Protection SOW

SCOPE OF WORK & TECHNICAL SPECIFICATIONS

FOR

INTEGRATION OF AL-KHAFJI BSPTO

EXISTING 115kV NETWORK

PTS-13EO1012

ENGINEERING & DESIGN DIVISION - EOA ENGINEERING & DESIGN DEPARTMENT

13-526-30502301 INTEGRATION OF NEW AL-KHAFJI 380/115/13.8KV BSP PAGE [2] OF [80]

1.0 GENERAL REQUIREMENT

a. The exact types and ranges of the relays and/or schemes; to be used; shall be subject to approval by the company.

b. Whether specified in details or not, the contractor shall provide the relays, protection schemes and all other related equipment/devices etc., to highest degree of engineering standards in judgment of the company.

c. The contractor shall be responsible for any omissions in delivering best quality engineering design and shall change / modify the scheme if it is observed by company that it does not meet the requirements to best engineering design.

d. Relay selection, its application, schemes, AC and DC wiring diagrams, relay and metering diagrams, schematic diagram

e. It is the contractor responsibility to visit the WORK SITE and to satisfy himself as to the extent of WORK, location and all conditions under which the WORK will be carried out. NO claims based on the lack of any such knowledge shall be entertained.

f. For numerical relays under this contract, it is the contractor responsibly to provide the latest updated configuration/settings original software(s) ensuring proper relays configurations and functionality of the entire protection scheme as approved by the company.

g. For all Numerical Protections provided under this project, all optional features as declared by the manufacturer must be provided including fault recording, event recording, GPS synchronization &

manufacturer(s) [softcopy & hardcopy] during Bid stage.

h. The CONTRACTOR'S setting proposals and configuration for any Numerical Relay, to be used shall be proposed and installed on PED computer for review, testing and approval during detailed design stage before drawings are issued for construction.

i. It is the CONTRACTOR/manufacturer's responsibly to ensure that relay(s) internal configurations are matched in the associated drawings. The CONTRACTOR shall ensure the same in the submitted drawings and provide all original and updated software(s).

j. CONTRACTOR shall update all drawings (protection AC/DC schematics, One line diagram, one line relaying and metering diagram etc.) affected by this work.

k. Additionally, all numerical relays involved in this project should be equipped with facilities and have the capability to be connected to the remote master station at ERB Hq.

l.Trip signal should be sent to remote ends.

SECTION I Protective Relaying Design Criteria


m. All proposed relays should be numerical relays type and provided with full options.

n. A minimum of two (2) years of satisfactory operating experience with a major electric utility. If the type of the test report is not considered to be comprehensive enough, the CONTRACTOR shall perform additional tests as specified by the COMPANY.

1.1 PROTECTION PHILOSOPHY

Design of the protective relay system shall have maximum reliability, selectivity and security. The protection of the substation(s) shall generally be achieved on primary circuit basis, except in few cases where the same shall be achieved on substation basis. The protective relays shall not maloperate under all normal service conditions. The protective relays shall also allow operation under abnormal emergency operation conditions but only upto limited duration, which shall be determined on case-to-case basis.

Under all conditions, the protection system(s) shall be designed such that it will initiate tripping action at the earliest such that equipment is saved from being damaged. Once faulty equipment/section/zone/portion is damaged shall be isolated at the earliest possible time. The protective system(s) shall coordinate with neighboring systems such that unwanted tripping are avoided. Whenever, requirements of high-speed and security shall conflict each other, the security shall be given priority over speed. However, maximum tripping time shall be governed by the requirements of tripping time specified in this specification. All areas of diametrically opposite interests of security and speed shall specially be brought to the notice of company for review/approval.

Each and every relay, relay system, relay schemes shall be designed in such a way that they shall not issue any mal-tripping signal. Maximum priority shall be given on achieving high degree of reliability. In order to provide definite trip, the protection of each equipment shall be based on one-out of two principles except for specified bus-bar wherein main and check zone relaying shall be followed. The protection of each primary equipment, except specified bus bar, shall be divided into two separate sets so called set-1 & set-2. Common device protections could be mounted in interface panels. Both set-1 & set-2 protections shall be electrically and mechanically separate for 115KV. Separation shall also be maintained in all AC & DC wiring. The criss- crossing must be avoided. For 115Kv line protection, set-1 & set-2 shall be from two different manufacturers.

In case criss-crossing cannot be avoided, the same shall generally be achieved through interface panels. Interface panels shall not be supplied if it does not house any relays. In applications, where interface panels is not available and crises-crossing is imminent and cannot be avoided e.g., inter-tripping of tripping function (lockout) relays, the same shall be provided but only after due approval of Company. The protection scheme shall be designed such that even if all protections of any one group is not available for any reason what so ever, the other group shall protect the primary equipment. Complete redundancy shall be maintained within frame work of this specification including DC supply wiring, cabling and cable selections etc., such that non-availability of any protection group of protection, DC supply, cables/cabling etc., shall not be the cause that equipment is not adequately protected. In case above requirement are not met, the contractor shall be responsible for the omissions and shall change/revise modify the wiring/scheme etc., even if they are installed/wired/commissioned at site.

Protection overlapping shall be provided around all CBs.

1.2 OVERALL CONSTRUCTION AND LAYOUT OF EQUIPMENT

Following basic requirements in construction and layout of protective equipment and panels etc., shall be met in substation.

Protection against environment.


Facilities to simplify maintenance and repairs.

Flexibility to allow future modifications and extensions.

Reliability in service.

Minimum space requirements.

Ease of installation on site.

Layout, separation and arrangement of panels shall be done by grouping protection systems on primary circuit basis to maintain each circuit in operation. While deciding the panel grouping, following criteria shall be fulfilled.

1. It must be possible to take out of service and work safely on the equipment for an individual primary circuit without risk of interfering with the operation of other primary circuit.

2. Provision must be made for the easy installation of equipment of new primary circuits.

3. It must be possible to disconnect the auxiliary supplies to the equipment associated with each individual primary circuit independently.

4. Clear segregation of the terminal wiring for each primary circuit must be provided to avoid error.

5. An outage of any part of the system must be acceptable for the time required to repair or replace the part and restore it to service.

6. A fault on any one equipment must not affect the continuous operation of equipment for other primary circuits. This requirements is also applicable to each protective system where duplicate systems are provided for one primary circuits.

Consequently following grouping shall be provided in protection of primary equipment.

i. Circuit Protections

Each primary circuit (lines, cable etc.) shall be protected by electrically and mechanically duplicate protections called set 1 & set-2. Segregation must be maintained between each

Relays shall have all their optional features available as per relay manual.

ii. Switching Device Protections of each primary circuit breaker.

iii. Auto-Reclosing equipment for each over head line (if specified).

iv. Bus Bar Protections including backup of each bus, bus-sectionalizer and bus coupler.

v. Various following systems and component shall usually be grouped together on a substation basis.

a. Sequence of event recorder, data logging, remote control and fault recorder etc.

b. Interfacing systems such as relays and transducers.

c. Synchronizing devices.

2.0 GENERAL TECHNICAL REQUIREMENT

2.1 RELAY TYPES


a. The exact types and ranges of the relays and/or scheme to be used shall be subject to approval by COMPANY.

b. Numerical type relays of modular design shall be used for protection and Electro-mechanical type all-or-nothing relays shall be used for tripping functions. DC/DC converters shall be provided for all numerical relays. Series resister type power supply units to drop the voltage are not acceptable. All the relay shall confirm to IEC60255. The relays used for transformer protection shall confirm to IEEE C37.91 STD. All over-current inverse time characteristics shall be selectable inverse to IEC60255 or BS-142.

c. Relay selection, its application, schemes, AC & DC wiring diagrams, relay and metering diagrams, schematics diagrams, terminal wiring diagrams, cabling diagrams, relay settings and coordination, etc. of all protection relays, and protective signaling equipment, etc., shall all be subject to approval of SEC-ERB.

d. Each protective relay, auxiliary relay, lockout relay etc., which either initiate tripping function (lockout) relays, and/or tripping to circuit breakers or initiate annunciation etc., shall be provided with positive means of indicating either by flag or LED. All definite time delayed tripping relays shall be provided with flag or LED indications only on their respective timer units but not in its instantaneous units. Hand or electrical reset targets/ indications shall be provided on all relays. In addition to above, all protective relays, auxiliary relays, lockout relays, tripping function relays etc., as stated above shall be provided with adequate contacts for following functions. If necessary, auxiliary relays shall be provided to accomplish these requirements.

Annunciation

Sequence of event recorders

Remote indication on SCADA

Fault recorder

Spares

e. The relays, inter-trip smatched at both ends of the line. The contractor of this project shall be responsible to ensure the matching of all devices, relays, equipment etc., such that the whole scheme will perform well to complete satisfaction of the SEC-ERB. The contractor of this project shall change/modify the relay/scheme, etc., if required by SEC-ERB to make the scheme functional in well-engineered and coordinated manner.

f. All drawings and instruction and maintenance manuals of respective protection schemes, protection-signaling equipment should be available to SEC-ERB for its review, relay setting and maintenance, etc. Adequate copies of the same should be supplied to SEC-ERB at various stages of the project.

g. All protective relays shall be immune to DC failures. They shall never operate on loss of DC supply.

h. Update all the existing drawings at all substations related to the project.

2.2 AC CURRENT CIRCUITS

The protective relaying system shall be designed for rated current as applicable at each substation/line equipment and be compatible with the respective current transformer secondary. The current circuit neutral shall be grounded at the entry terminal blocks in the relay panel. In


case of summation of currents by direct galvanic connections, the neutral shall be grounded at one point at the entry terminal block.

Separate current transformer cores shall be used for relay set-1 & 2. CTs provided shall be as per CT requirement section of this scope.

2.3 AC VOLTAGE CIRCUITS

The protective relaying system shall be designed for 3-phase, 60Hz system, and shall be compatible with the voltage transformer secondary.

Single-phase secondary circuits of the voltage transformers shall be interconnected and grounded in the first entry block at the relay panel. No grounding in addition to the above shall be employed in the galvanically connected system of voltage circuits.

Also, separate circuits shall be provided for protection, synchronizing, metering and SCADA. Grouping of various circuits shall be done via first junction box from potential transformers, where each circuit shall be provided with high speed miniature circuit breaker or fuses for protecting the secondary circuit. Separate potential transformers secondary winding shall be used for relay set-1 & set-2.

2.4 AUXILIARY DC SUPPLY

Two DC supplies shall be provided for protection of each equipment. All DC supplies shall be provided with separate switch and fuse units such that failure of any fuse or supply shall not jeopardize other group supplies.

All fault recorders, sequence of event recorders indications, alarms, following relay functions (if any), metering transducers etc., shall be on looped supply for respective voltage levels.

The auxiliary DC supply required for all protective relays, tripping relays, breaker trip and closing coils, auxiliary relays, etc., shall be from station battery. The voltage rating of these shall also be same as that of respective station battery voltage. All relays, coils and other associated devices shall operate satisfactorily in the voltage range of station DC system within + 10% and - 20% and also in accordance with IEC60255 Std. for relays.

2.5 TRIPPING TIME

The tripping time of protective relaying shall be most critically adhered to. The tripping time shall be measured from time of occurrence of fault to the time when circuit-breaker tripping coils are energized. For all high speed/instantaneous form of protective relaying following tripping time shall not be exceeded. Silicon Controlled Rectifier (SCR) outputs or any static output shall not be used to reduce the tripping time.

The max. operating time of protection for major equipment is as follows :

a. 115KV Line Protections

45 msec for fault at mid-point of line.

50 msec for fault at relay locations.

b. 115kV Bus bar Protection

50 msec. at minimum fault current.


c. 115kV Transformer Protection

All ratings: less than 40 ms

NOTE:

The above tripping time shall; but not limited to; include relay operating time + carrier or fiber optics signaling time (if any) + tripping functions (lockout) relay time. It implies that if more time is lost in relay, the same shall recovered from other devices and vice-versa. However, tripping time of individual devices/relays shall not exceed those specified in respective clauses.

The tripping time of backup/slow operating relays shall include relay operating at its setting plus lockout-relay operating time. In cases, where instantaneous units are provided along with over-current protections, the maximum tripping-time from instantaneous unit shall not exceed 40 msec for any application.

In application, where operating time is excessively reduced due to use of ultra high speed relays, or where operating time exceeds the above set limits, special approval shall be obtained from company who may reject any or both proposals. And in case of any of such rejections above time limits shall be binding on the contractor.

Cascade application of multiple lockout relays is not allowed and should not be practiced for tripping functions. Series flag relays should be used where required.

2.6 SENSITIVITY:

The sensitivity of line, BF & busbar relays shall be to operate at 10% rated current.

2.7 OVERLOAD RATINGS:

The protective relays shall have the following minimum overload capabilities:

AC Voltage : 1.2 x Rated Voltage continuous

2.0 x Rated Voltage for 10 seconds

AC Current : Minimum Continuous Currents of 3 x Rated

Minimum 10 Seconds Current of 20 x Rated

Minimum 1 Second Current of 70 x Rated

2.8 TRIP CIRCUITS AND TRIPPING AND/OR LOCKOUT RELAYS:

Trip circuits for relay sets 1 & 2 shall be electrically and mechanically separate from each other. Trip power sources for the relay sets 1 & 2 shall be from the batteries No. 1 & 2, respectively (if any).

Trip coils of the breaker shall be energized via auxiliary electro-mechanical tripping relays. One set of tripping and/or lockout relays shall be provided for each set/group of protection relays. The tripping and/or lockout relay shall not have operating time in excess of 10 milliseconds of rated voltage. Tripping and/or lockout relays of set-1 shall trip coil-tripping and/or lockout relay of set-2 shall tip coil-relays with operating voltage of less than 50% of rated voltage are not acceptable. Tripping and/or lockout relays shall operate between 80% to 110% of rated voltage with their operating


time within guaranteed and specified limits. Relay should never maloperate due to cable/other capacitances in the entire DC system and boost charging voltage level. The contractor should justify this by calculation with respect of the total distributed capacitance on the DC system and also field test should confirm it.

Supervision relays shall be provided for each and every lockout/ tripping relay coil and its DC supply.

All lockout relays shall be of mechanically latched type design with electrical or manual reset. All tripping relays used for line protection and transformer mechanical targeting function auxiliary relays applications shall be of self-reset with hand reset target type.

All lockout/tripping relays shall have 3 NO & 2NC contacts available as spare and wired upto terminal blocks of respective panels.

For transformers protection, lockout relays of primary set 86-1 and 86-3 shall energize trip coil-1 of HV/LV CBs and lockout relay of backup set 86-2 and 86-4 shall energize trip coil-2 of HV/LV CBs. For lockout relay classification, refer to Relaying and Metering One Line Diagram of new substation.

All tripping, lockout and receive relays shall be of high burden, high security type. These relays should not operate due to capacitive discharge currents due to cabling in the DC system or any devices in the DC system. The CONTRACTOR must justify the relay stability by calculation and field test.

2.9 TESTING FACILITIES:

All individual relays used in the protective relaying shall be tested in accordance with the requirements of IEC-60255 or equivalent ANSI, British etc., as per company and manufacturer recommended test practices.

Each protective relay shall be capable of being tested completely from the front of the panel. Manufacturer test blocks shall be provided. Company approved manufacturer test blocks shall be provided. FT switches can be used if manufacturer test blocks are not available or not acceptable. However, in this case one testing facility to isolate both AC/DC at the same time shall be provided. Test switches shall facilitate shorting and grounding of the CTs and be clearly labeled. Each tier of the protective relay rack (regardless of the number of relay manufacturers in that tier) shall be equipped with sufficient number of test blocks to facilitate individual relay testing. by COMPA

All protective relays shall be capable of being tested individually, with adequate safety and without the risk of spurious tripping. Single-phase relays shall be equipped with separate test blocks to facilitate testing of relays individually and carry out load check.

The design shall be such that external test equipment can be connected to the protection system at a permanently mounted connector in front of the relay panel by means of test plugs.

Special test equipment supplied by the relay manufacturers and required or recommended by the relay manufacturers for acceptance and/or maintenance test shall be provided. This shall include connecting cables, plugs & operating manuals etc.

For relays equipped with serrelevant software and connecting cords shall be provided.


2.10 RELAY SETTINGS AND CTs SIZING CALCULATIONS:

The contractor shall furnish basis of relay settings and shall provide all relay setting calculations for each and every relay and timers etc used for the project.

Moreover, the contractor shall provide the settings calculations for the above subject project from the manufacturers and submit the same to SMD/PED.

The details of equipment to be protected are stated in this specification. The company shall approve relay settings furnished by the contractor. If, in judgment of company, it is observed that the relay setting(s) is (are) wrong, the contractor shall furnish revised calculations or relay settings. Also, in case, it is found that relays installed at site cannot meet the required settings, the contractor shall change the relay, relay wiring, testing commissions etc., without any additional price to complete satisfaction of the company.

The contractor shall provide preliminary relay settings, relay calculations, CT and relay suitability calculations at the earliest for all equipment along with related instruction manuals and documents on the basis of which these settings were calculated.

The CT and relay suitability calculations shall be furnished by contractor along with the tender. The recommended relay settings and relay calculations for each station shall be furnished by the contractor six (6) months before commissioning date of the respective substations. The time-current grading shall be provided for all over-current relays on log-log sheets separately for phase

for load sheddinused.

2.11 TRIP COILS AND DC SUPPLY SUPERVISION:

-

All DC supplies shall be supervised by DC supply supervision relays.

Trip-coils supervision relay shall be provided to supervise the trip coil, DC supply and all tripping wiring loopings etc., of all trip function/lockout relays.

Trip circuits supervision relay shall be provided to continuously supervise each trip coil of CB, whether the breaker is open or closed. The supervision shall include the DC supply, trip coils, all inter-connection cabling and when the breaker is closed auxiliary contacts for the coils. Where the circuit breaker is of single pole version the each pole trip coil must be individually supervised.

The contacts of above supervision relays shall be time delayed on drop-out by approximately 100 msec to cater for transient voltage dip conditions. The relay shall have adequate number of contacts for providing alarm, SOE and SCADA etc.

2.12 CT CIRCUIT TERMINAL BLOCKS:

The CT terminal blocks at the first accessible point of termination at the device (power circuit breaker, power transformer cabinet, switchgear cabinet etc.) shall have shorting and grounding facilities by means of a copper bar with shorting screws with the design similar or equivalent to the GE terminal board type EB27B06SC. The design shall be such that the removal of the shorting screw shall not cause any CT circuit opening. The terminal blocks used for termination of the CT cables in the marshaling boxes and panels shall contain no slide links and should be correctly sized to accommodate the required conductor sizes. Each CT shall have shorting and


isolating facilities at the first panel of entry in the control room or in the case of the switchgear, the control cabinet.

NOTE:

The first panel of entry, control panel or relay panel for a CT circuit shall have a shorting type terminal block similar or equivalent to the terminal block used at the power circuit breaker and power transformer cabinet etc.

2.13 CT, PT, CONTROL CABLES

All control cables for CT & PT/CVT circuits for various relaying, recording and metering functions shall be lead sheathed/shielded type unless relay or recorder manufacturer additionally requires twisted pair cables also. The shield shall be grounded at both ends, i.e. in 115KV GIS S/S and in relay/control house at inlet of the concerned panels. The cross sectional area of the cables and current carrying capacity of the shield shall be adequately sized to suit the application. The Contractor shall furnish the calculations for approval of the Company. Maximum cross-sectional area of the CT lead shall not exceed 10mm² cu. Neutral of all CT and PT shall be grounded at first entry point in relay panel. However, facility shall be provided to ground CT & PT neutrals (temporarily for maintenance purposes) in switchyard also. In any case neutral shall be grounded at only one place at a time and that is in relay room for permanent position.

2.14 PT FUSE-FAILURE SUPERVISION RELAY:

Fuse-failure relays shall be provided to supervise both failure of PT fuses and any open circuiting of PT secondary circuits/loopings etc. Thereby, PT fuse-failure relay shall be connected in the end of PT secondary looping. The fuse failure relays shall supervise single, poly and three phase fuse-failure conditions. The operating time of the fuse-failure relay shall be less than 8 msec such that its output can be used to block protection from maloperation. For 3- -failure relay shall be based on either detection of zero-sequence voltage or balanced voltage principle. The relay shall not maloperate on system ground faults. Zero-sequence current

o' principle. Additional voltage signal parallel to any of the fuses shall be provided to make relay suitable to detect 3-phase fuse-failure for

relays operating on Vo principle. For single-voltage balance principle. The relay shall be provided for each relay utilizing voltage supply such as distance, DEF, directional O/C, neutral displacement, synchro-check relays and dead-line/bus check feature (where provided).

a. Relaying standards

b. For capacitor bank protections

ANSI/IEEE C37.99 - 1990 - IEEE guide for protection of shunt capacitor banks.

As per specification.

c. For other protections

As per specification.

2.15 SURGE PROTECTION TO CT's, PT's, RELAYS AND CONTROL CABLES


a. Surge protection for various current-transformers, voltage transformers/CCVT's, relays shall be provided and complete system shall be designed to meet the requirements of clause 10.6 of IEEE C37.99-1990.

b. All control and relaying + metering cables and cabling schemes shall be designed to meet recommendation of clause 10.7 of IEEE C37.99-1990.

c. Overvoltage protection and surge withstand capability of CT's, its primary and secondary wirings; CT neutral grounding etc. shall be designed to meet requirements of clause 10.5 of IEEE C37.99-1990.

d. Control cabling shall be done between end-to-end/without any junction point in between.

2.16 INSTRUCTION AND MAINTENANCE MANUALS:

a. not brochures) shall be provided to Protection Engineering Division of company and accepted prior to acceptance of relays or relay systems. Other complete manuals must be provided to the company before relays or relay systems are delivered to the construction site. This information shall allow the company to determine all settings, to set and calibrate, to verify correct installation and connections, and to repair in place the relay or relay system.

b. Information in the manuals and documentation for the relay system shall not contain less than the following:

pecification and characteristics.

External connections.

Description and drawing of the construction and principals of operation. Additionally for relay systems, the module layout, interconnection drawings, internal wiring, and component descriptions.

All setting calculation instructions explained with examples.

All setting and calibration procedures and instructions.

Receiving inspections and acceptance test on instructions.

Installation requirements and instructions.

Routine maintenance requirements and instructions.

Repair and recalibration instructions.

Parts list.

Design test reports.

2.17 DRAWINGS AND PROTECTION SCHEMES

All new drawings shall be made according to SEC-ERB standard specification No. SES-P-119-33. Existing drawings at all stations related to this project shall be revised by being re-drawn showing

with new revision number. Drawing size shall be as per company requirement.

2.18 CT REQUIREMENTS:

The existing CT's at all involved substations shall be used with the new protection relays unless found inadequate or otherwise specified.


Irrespective of the CT tap used, each new CT shall have required continuous thermal rating in accordance with the primary connected equipment maximum capability & shall also be suitable for Relay thermal ratings.

Number of CT cores and their requirements to be provided on either side of CBs shall be coordinated with all concerned departments, and also shall meet the protection requirements as required by the intended protection.

PX of IEC-61869/TPS IEC 60044-6 unless otherwise specified.

VA burden (if any) shall be minimum 125% of required.

All new CTs for all new protection provided under this project must be justified for the requirement in accordance with the Relay Manufacturer's recommendations and PTS requirements (whichever is higher).

, RCT, Rb etc must be attached for each & every class CT involved under the project

Also, note that required parameters for the CTs indicated in this PTS & drawings are only minimum requirement & are not a limiting factor for the performance of any CT. Should any CT with higher performance, change in tap etc becomes necessary as per the calculations performed by the contractor, the same shall be highlighted and proposed for the Company approval. However, no justifications or proposals for CTs with lower performance than PTS indicated on any parameter will be accepted.

For Secondary circuit wire length cable route layout must be attached for each & every protection. A multiplication factor of 1.2 shall be used over the length as per proposed cable route plan

For all protective cores, minimum safety margin of 20% in knee point voltage shall be provided. In addition, to above, the knee point voltage shall be rounded to nearest round/whole figure.

The calculations for selection and sizing of all CTs shall be furnished by the contractor along with tender for approval by the company. CTs shall not be procured prior to CTs approval. If in its judgment of the company these CTs found not adequate, contractor shall change the CT and provide adequately sized CT.

All protection CT cores shall have continuous thermal rating of two times In i.e., 2 x In for all taps.

CTs shall be located on either side of CBs to provide complete overlap of protections around the CB.

All protection class CTs shall be identical, so that their interchangeability could be possible.

Breaker interrupting capacity shall be used as basis for CT sizing.

All spare bays CTs for future protection shall be sized both for distance and line differential protection by considering Minimum length 4 km for distance protection & 1 km for line


Minimum two (2) tap steps on higher side and three (3) tap steps on lower side in CT ratio must be available to cope up with future modifications in the grid/system operating conditions.

In case any protective (distance, differential) relay requires lower knee point voltage than those calculated above, the same shall not be accepted unless and until relay manufacturer furnishes type test report to prove the CT requirements without increasing the relay operating time under full CT remenance and 100% DC off-set conditions and 3-open-close sequence.

In case knee point voltage at the highest tap of the CT core is more than 2000V (r.m.s) suitable non-linear surge suppresser devices (e.g. lightening arrestors etc.) shall be permanently wired in parallel with secondary winding of respective CT core in respective CT terminal box located in switchyard to limit the peak voltage less than 3000V (peak). The calculations to prove the application and characteristics of above non-linear surge suppresser device shall be furnished by contractor for the approval of the company.

(maximum CT knee point voltage requirement for various protections at applicable tap). In these calculations the short circuit level shall be the short circuit interrupting capability of the circuit breaker.

Following formulae shall be used in sizing the minimum CT knee point voltage requirements for various protections at applicable tap irrespective of type of relay used. In case, any particular relay requires more CT knee point voltage, the same shall be overriding these requirements. Margin shall be provided for remanence while using CT adequacy formula. The calculations shall be based on CB interrupting capacity.

a. For distance protections

The higher of the following two requirements shall be chosen:

a. Vk1> If1. (X/R+1) (RCT+Rl+Rr+Rb)

b. Vk2> K.If2.(RCT+R1+Rr+Rb)

WHERE:

Vk1 & Vk2 Knee point voltage (rms)

If 1 Fault-current (sec) for fault at the reach of zone-1 relay.

If 2 Fault-current (sec) for fault at the relay location.

RCT CT secondary winding resistance at the tap.

Rl Cable lead resistance (both ways total)

Rr Relay resistance.

Rb Resistance of all other relays/burdens connected on the respective CT core.

X/R Ratio of total system reactance to resistance at relay each


K (1+X/R) subject to multiplication factor as recommended by the relay manufacturer which shall be approved by the company.

b. Transformer Differential Protection Relay

Vk KIs ( RCT + RL + Rr + Rb ) or as per manufacturer's recommendation.

WHERE:

Vk CT knee point voltage (rms)

Is Rated CT secondary current

RCT CT secondary winding resistance at selected tap

RL Cable lead resistance (both ways total)

Rr Relay resistance

Rb Resistance of all other relays/burdens connected on respective CT core

K Constant as recommended by the manufacturer inrush through fault and D. C. transients

The above requirement presumes that if CT saturates after six (6) cycles, it will have adequate harmonics in its secondary to make relay remain stable on through fault. In case the offered relay does not remain stable, the number of cycles shall be suitably increased. The transformer differential HV side (115kV) CT shall have extended thermal rating of 2xIn (In is rated current of CT). The CONTRACTOR shall furnish the calculations along with its justification to prove the above requirements to COMPANY for its approval.

c. Restricted Ground Fault Protection, STUB BUS and High Impedance Bus Bar Differential Protection

Vk > 2Vs

Vs > K.IFs (RCT +2 Rl)

Ip = T. (Ir+nIm+IM+Isp+Iv)

WHERE:

Ip Primary fault current (min. effective)

Vk Knee point voltage (rms)

Vs Relay setting voltage

K Constant (e.g. 2)

T CT ratio

Ir Relay operating current

n Number of CTs in parallel


IM Current taken by voltage limiting device at Vs volts

Isp Current taken by fault setting resistor at Vs.

Iv Current taken by CT supervision relay

IFs Maximum secondary fault current i.e. CB rating for busbar protection.

Im Magnetizing current of CT at relay setting voltage.

Rct, Rl Same as in distance protection.

NOTE:

All CTs involved in these protections should have matching characteristics in ratio, Vk, Im and design etc.

d. Low impedance bus bar differential protection

Specific recommendation of CT requirements of offered relay shall be furnished by contractor along with his tender. The CT requirement recommendations shall be supported by high-current tests on through fault stability and extreme transient CT saturation including high degree of remenance in the CT. The CT shall have knee point voltage derived by the formula recommended by relay manufacturer.

e. For inverse time protection

To suit the applications provided inter-changeability and other requirall.

The CT shall have Knee-point voltage derived from the following formulae:

Vk > Is (RCT + RL + Rr + Rb)

WHERE:


Is CT secondary current corresponding to Switchgear interrupting current.

RCT, RL, Rr, Rb Same as in distance protection

f. For instantaneous over-current protection

Accuracy limit factor must be at least as high as the value of the setting current used but it should not be lower than 80 to 90 p.u. to avoid excessive saturation of CT and hence possible non operation of relay due to CT saturation unless high current tests really prove positive operations of relay for higher ALF.

The CT shall have Knee-point voltage derived from the following formulae:

Vk > 2 Is (RCT + RL + Rr + Rb)


WHERE:


Is CT secondary current corresponding to Switchgear interrupting current.

RCT, RL, Rr, Rb Same as in distance protection

g. For the capacitor protection

13.8KV Overcurrent CT requirements

The CT shall have a rated primary of 1.4 times rated current of the bank. And rated to full system voltage.

The CT Knee voltage calculation shall be based on the manufacturer recommendation.

All CTs shall PX class as per IEC 44-6

h. Line differential protection relay

Vk kIn (RCT+2 RL)

WHERE:

K secondary through fault current x primary X/R ratio is less than 350In.

When the above product is 350In then ,

K a constant as recommended by the manufacturer supported by justifying calculations by the manufacturer subject to COMPANY approval.

Vk Knee point voltage of current transformer for through fault stability

In CT rated current

RCT Resistance of current transformer secondary circuit (Ohms)

RL Lead Resistance of single lead from relay to current transformer (Ohms)

2.19 Operating Time of Auxiliary Relays for SOE/TFR etc.

In all applications that require high-speed performance for SOE/TFR (e.g. inter trip signal receive) and various applications which require input to SOE and fault-recorder etc.) Various auxiliary relays (if used) shall have its operating time of typical 1 msec, at rated voltage. The number of contacts shall be provided as required to meet specification requirements. In all other general type applications, the operative speed of auxiliary relays shall be within 4 to 10msec depending on application. In case it is more than above value, special approval from the Company shall be taken. Signals send/receive functions for protection shall be performed directly without using any multiplication through aux devices.

2.20 Requirements for Numerical Relays for Data Retrieval System.


The requirements for Numerical Relays for data communication shall be as follows:

Evaluation Master Station PC (latest type) should be provided to PED at SEC-ERB HQs, which shall through the Substation

Automation System (SAS) Engineering Workstation PC (for Substation with SAS) and through data retrieval system (for substation without SAS) for Relay monitoring & data retrieval and Analysis. This is required to & from all involved substations under this project to PED Evaluation center.

to have full access to the numerical relays including software/hardware required to get the system functioning shall be provided.

The communication protocol used should conform to a well-known standard and should be capable to be upgraded to any further new systems (open system) as per the SAS appendix. This shall be compatible with various type & make of Numerical Relays involved under this project at each S/S end.

Required setting & configuration software shall be installed on PED PC during detailed design stage

numerical relay to be used shall be proposed and installed on PED computer for review, testing and approval during detailed design stage before drawings are issued for construction.

A detailed training on the installed Relay monitoring & data retrieval and Analysis system for both engineering & field personnel shall be provided.

All proposed relays should be numerical relays type and provided with full options.

2.21 Impedance Measurements for all transmission lines/cables involved in this project:

The following requirement shall be included under the T/L PTS under relevant section:

a. SOIL RESISTIVITY MEASUREMENT

There shall be sufficient number of Measurements for various 'Electrode spacing' (in tabular form) to provide a clear indication of Resistivity of various underlying layers. These tests must be performed in strict compliance with IEEE Guidelines under standard 81. These measurements shall be accompanied with calculations and 'interpretations' as per the mentioned standard.

Finally, based on the soil Resistivity pattern and other Geotechnical considerations and involved standards, the T/L contractor shall provide equivalent single soil Resistivity value for use with HV and EHV fault calculations, suggested by an approved 'Independent Agency'.

These measurement and Equivalent Soil Resistivity values must be submitted individually for each T/L under this project.

E&DD/EHVE&DD shall include this requirement in the relevant section of the PTS to be provided at the 'Final Line construction stage'. These data must be submitted to SMD/PED as well as to the S/S contractor in order to prepare relay settings & fault analysis.

b. IMPEDANCE MEASUREMENT

The contractor shall have line impedances measured by 'TWO INDEPENDENT APPROVED' agencies for all newly constructed lines.


The measurement shall provide the following individual impedances accompanied by various measured voltage and measured currents as well as Test circuit diagrams for each impedance measurement (all impedances must be in rectangular form R+jX):

Zab

Zbc

Zca

ZaE

ZbE

ZcE

Z0 with parallel line open & grounded at one end only

Z0 with parallel line open & grounded at both ends

In accordance with the standards involved, Positive sequence Impedance shall be evaluated as Z1 = (Zab+Zbc+Zca)/6.

Average value ZPh-E of measured Phase-Earth impedance, where ZPh-E = (ZaE+ZbE+ZcE)/3, shall be checked with theoretical calculations ZPh-E calc (ZPh-E calc shall be evaluated using Z1 and measured Z0 as determined above from ZPhE calc=(2Z1+z0)/3. The difference between ZPh-E and ZPh-E calc shall not exceed 2%. Failing which, repeated measurement shall be performed to satisfy the accuracy within 2%.

With parallel line open and grounded at both ends again, average value ZPh-E of measured Phase-Earth impedance, where ZPh-E = (ZaE+ZbE+ZcE)/3, shall be checked with theoretical calculations ZPh-E calc (ZPh-E calc shall be evaluated using Z1 and measured Z0 as determined above from ZPhE calc=(2Z1+z0)/3. The difference between ZPh-E and ZPh-E calc shall not exceed 2%. Failing which, repeated measurement shall be performed to satisfy the accuracy within 2%. Here, Z0 is effective reduced z) value due to parallel line mutual i.e. Z0 = (z0 - ZOm²/Z0), where z0m is zero sequence mutual impedance.

The value of Z0m shall be provided along with Z1 and Z0.

c. CALCULATED IMPEDANCES

The Contractor shall provide line impedance calculations for all T/L lines based on physical line construction using 'Equivalent Soil Resistivity'. These calculated impedances shall be submitted to SMD/PED and S/S contractor for each line at the time of start of the project as well as at the time of final testing of the lines.

d. LINE CONSTRUCTION DATA

Line construction data must be submitted for each line. The data shall be submitted at end of final construction and shall include the following for each line individually:

Power conductor type, size and details of strands

Bundle details (i.e. numbers of conductors per phase)

Bundle spacing in inches

If more than two conductors per phase alpha angle

Typical structure configurations.


Spacing coordinate X, Y for each phase conductor (X=0, Y=0 shall be centre line of structure at ground surface).

Sag for phase a, b & c (average, minimum and maximum).

Ground wire type, size and details.

Spacing coordinate X, Y for each Ground wire (for both OPGW & OGW).

Sag for each ground wires (average, minimum and maximum).

le,

Sag table for each span

Plan and profile drawing for each line

Parallel running line information in sketch form with name, KV and length marked for each parallel line.

Transposition details, phasing and length in sketch for from end to end.

Total length of line from Bus-bar to Bus-bar at two ends (i.e. Gantry to Gantry + Gantry to GIS or CB).

2.22 Bid proposal form

All bid proposals shall be submitted as per the form as per attachment BIDDER FORM. Any submitted bid proposals shall be completed in this form and any bid submittals with missing/ omitted information shall not be reviewed by SMD/PED.

It is the concern department/division responsibility to make sure all bidders have this form and use it for there submittals.

2.23


A. NEW AL-KHAFJI 380/115/13.8KV BSP SUBSTATION

1. 115kV Protection Relay Panels:

The CONTRACTOR shall provide and install the following new 115kV relay panels in the substation control building. Number of panels shall be decided based on detailed design schemes & space requirement and as per E&DD requirements.

Relay panel(s) for transmission line containing set-1 protection.

Relay panel(s) for transmission line containing set-2 protection.

2. 115KV Line Protections:

2.1 KHAFJI SUB-2 Line Protection:

The following are the required new protection sets for 115kV line to KHAFJI SUB-2 at NEW AL-KHAFJI 380/115/13.8KV BSP Substation.

SET # 1

New Line Distance set (21/DEF-1) for 3-phase and ground fault protection. The relay shall be numerical type with built in DEF (67N) and O/C (67 & 67N) for phase and ground faults and provided with full options (as per the related attachment DIS-21).

Electro magnetic tripping relay (94-1) with adequate contacts for alarms, SOE, TFR etc.

Supervision relay (74) for tripping relay (94-1).

Trip coil supervision relay (74) for TC-1 of CB.

DC supervision relay (74) for DC-1 set 1.

PT fuse failure relay (98) for blocking the 87L built-in distance feature and DEF (67N)

Receive relay (85DTTR) with operating speed of less than 10msec., self-reset type with the target shall be provided for each breaker failure/ pole discrepancy protection channel for NEW AL-KHAFJI 380/115/13.8KV BSP S/S line. This relay shall be provided on Set # 1 protection portion of the panel and will operate 94-1 & 94-2.

SET # 2

SECTION II Protection Relaying Requirements


New Line distance set (21/DEF-2) for 3-phase and ground fault protection. The relay shall be numerical type with built in DEF (67N) and O/C (67 &67N) for phase and ground faults and provided with full options (as per the related attachment DIS-21).




DC supervision relay (74/DC-2) for set -2.

PT fuse failure relay (98) for blocking the 87L built-in distance feature and DEF (67N).

NOTE:

Set-2 should be from different manufacturer than set-1.

AUTO-RECLOSING SCHEME:

New Auto-Reclosing relay (79) for selectable high speed & delayed reclosing of 115kV line shall be provided as stand alone along with dedicated synchro check plus live-line/dead bus and dead-line/live-bus scheme per CB for the line with Fuse supervision Relays (for each VT input of each sync check relay), Dc supervision relays etc. The auto reclosing relay & its scheme shall be (As per the main relay specification attachment AR-79+25).

CT REQUIREMENTS:

The existing CT's at Khafji-2 shall be used with the new line distance protection . It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.

Contractor shall get the complete data of the existing CTs of the respective CTs at remote end substations. The new CTs shall be sized as per requirement provided in this scope.

The minimum thermal rating for CTs when not specified shall be two (2) times rated at all taps.

All CTs shall be multi-ratio type. Two (2) taps above and two (2) taps below the indicated tap shall be used. Margin shall be provided for remanence while using CT adequacy formula. The calculations shall be based on CB interrupting capacity.


2.2 KHAFJI SUB-5 Line Protection:


SET # 1








SET # 2







NOTE:





CT REQUIREMENTS:





2.3 KHAFJI SUB-4 Line Protection (both lines):


SET # 1

New Line Differential set (87/21/DEF-1) for 3-phase and ground fault protection. The relay shall be numerical type with built in Distance, DEF (67N) and O/C (67 & 67N) for phase and ground faults and provided with full options (as per the related attachment 87L).








SET # 2







NOTE:


CT REQUIREMENTS:

The new line differential protection shall be suitable for used with the existing CT's at Khafji-4. It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.





2.4 KHAFJI SUB-3 Line Protection (Both lines):


SET # 1








SET # 2







NOTE:





CT REQUIREMENTS:





2.5 RAS AL-MISHAB PORT Line Protection:

The following are the required new protection sets for 115kV line to Ras Al-Mishab Port at NEW AL-KHAFJI 380/115/13.8KV BSP Substation.

SET # 1








SET # 2







NOTE:




CT REQUIREMENTS:




3. Existing 115KV system:


The existing Khafji BSP 115KV breaker failure scheme, 115KV under frequency scheme and pole discrepancy scheme shall be modified to be used with all new lines protections. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.

Also, the existing breaker failure scheme shall be modified to transfer trip the LV side breakers of the Khafji-1 Transformers.

Moreover, existing bus bar protection shall be modified to include the 115kV feeders/Transformersetc, shall be provided by the contractor.

B. KHAFJI SUB-1 SUBSTATION: The existing 115KV lines protection, 115KV Bus bar protection, 115KV Bus section protection, transformer 87T, 87REF & O/C HV protection shall be dismantled and returned to the company.

1. 115kV Protection Relay Panels

The CONTRACTOR shall provide and install the following new 115kV relay panels in the substation control building. Actual number of relay panels shall be decided based on detail design scheme & as per the standard 115/13.8KV SOW/TS.

2. 115/13.8KV Power Transformer Protections ( Each Transformer ):

Each 115/13.8KV power transformer new numerical protection requirements are as follows:

SET-1:

One (1) numerical three phase percentage biased differential protection (87T) with harmonic restraints provided with Interposing CT's suitable for use with 1A on HV side & 5A on LV side. (as per the related attachment 87T).

One (1) restricted earth fault (high impedance type) protection relay (87REF). (as per the related attachment 87REF). The relay shall be based on high stability circulating current relay with externally mounted, continuously variable series stabilizing resister and current range 5% to 40% In.

New lockout relays (86) for tripping HV and LV sides of the transformers (the number of lockout relays shall be similar to the existing lockout relays).

lockout supervision relays (74/86) .

One (1) DC supervision relay (74/DC-1).

The auxiliary relay shall be provided with adequate number of contacts for trip, alarm, SOE, SCADA and as spare.


Auxiliary targets relays for transformer mechanical protection shall also have the same performance requirements as the line tripping relay.

SET-2:

Two separate numerical relay each having (3) phase (50/51) and ground (50N/51N) over current protection shall be provided for transformer high side connected in series. The phase and ground Over current functions shall have a harmonic restrained. (as per the related attachment 50/51P&N)

One numerical (3-Phase & Ground), directional over current protection relay (67 and 67N) having selectable inverse time characteristics with instantaneous unit for transformer low side. (as per the related attachment 67/67N and 50/51P&N).

Provide PT fuse failure relays (98) for blocking each voltage dependent protection.

One (1) numerical neutral time over current protection relay (51G) with selectable inverse time characteristics. (as per the related attachment 50/51P&N, but without instantaneous unit).

Buchholz protection for both main tank and OLTC (63), having two (2) stages (one for alarm and one for tripping).

New lockout relays (86) for tripping HV and LV sides of the transformers (the number of lockout relays shall be similar to the existing lockout relays).

lockout supervision relays (74/86)

One (1) DC supervision relay (74/DC-2).

Lot - Separate auxiliary high burden voltage operated relays for trip stage with hand resettable target for the following transformer safety devices:

o Buchholz Relay Trip (Annunciator, SCADA)

o Winding Temperature Trip (Annunciator, SCADA)

o Oil Temperature Trip, (Annunciator, SCADA)

o Pressure Relief Device Trip for Main Tank and OLTC (Annunciator, SCADA)

o Pressure switch trip for OLTC (Annunciator, SCADA)

The auxiliary relay shall be provided with adequate number of contacts for trip, alarm, SOE, SCADA and as spare.

Auxiliary targets relays for transformer mechanical protection shall also have the same performance requirements as the line tripping relay.


Lot - Auxiliary voltage operated high burden relays for alarm stage with self reset coil and hand reset target, with adequate number of contacts for alarm, SCADA and as spare, shall be provided for the following function/device:

o Buchholz Relay (1st stage) Alarm

o Winding Temperature - High (1st stage) Alarm

o Oil Temperature - High (1st stage) Alarm

o Magnetic Oil Level - Low Alarm

o Cooler Trouble Alarm

NOTE :

The arrangement of 115/13.8kV power transformer lockout relays shall be exactly similar to the existing lockout arrangements and tripping scheme.

CT REQUIREMENTS :

The contractor shall propose new transformer differential with Interposing CT's that are suitable for use with the existing CT's at Khafji BSP (5A) on HV side & at Khafji-1 13.8KV LV side (5A CT).It is the contractor responsibility to provide the calculations for the Interposing CT's proving their suitability for use with the transformer differential protection (5A & 1A).

It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.



The existing Khaji BSP 115KV breaker failure scheme, 115KV under frequency scheme and pole discrepancy scheme shall be modified to be used with the new line protection. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.

Also, the existing Khaji BSP breaker failure scheme shall be modified to transfer trip the LV side breakers of the Khafji-1 Transformers.

Moreover, existing Khaji BSP bus bar protection shall be modified to include the 115kV feeders/Transformers. Any materials including bay units, etc, shall be provided by the contractor.


1. Existing 13.8kV Automatic Bus Transfer Scheme (ABTS)

The existing ABTS scheme shall be modified to include the new Transformers' lockout relay and the existing ABTS logic/scheme shall be used/followed.

The CONTRACTOR is responsible for the automatic switching scheme in a fully operational order. Any material required shall be supplied. The CONTRACTOR is responsible for any existing equipment being utilized in the scheme. The proposed scheme shall be reviewed and approved by the COMPANY. The scheme shall be thoroughly tested during commissioning.

C. KHAFJI SUB-2 SUBSTATION:



2. 115KV Line Protections :

2.1 NEW AL-KHAFJI 380/115/13.8KV BSP 115KV Line Protection :

SET # 1








SET # 2








NOTE:




CT REQUIREMENTS:




The existing Khaji Sub-2 breaker failure scheme, Bulbar differential scheme shall be modified to be used with the new line protection. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.

Also, the existing Khaji Sub-2 breaker failure scheme shall be modified to transfer trip the LV side breakers of the Khafji-1 Transformers.


Moreover, existing Khaji Sub-2 bus bar protection shall be modified to include the 115kV feeders/Transformersetc, shall be provided by the contractor.

D. KHAFJI SUB-5 SUBSTATION:




2.1 NEW AL-KHAFJI 380/115/13.8KV BSP 115KV Line Protection :

SET # 1








SET # 2








NOTE:




CT REQUIREMENTS:

The existing CT's at Khafji-5 shall be used with the new line distance protection. It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.



The existing Khaji Sub-5 115KV breaker failure scheme, 115KV under frequency scheme shall be modified to be used with the new line protection. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.




E. KHAFJI SUB-4 SUBSTATION:




2.1 NEW AL-KHAFJI 380/115/13.8KV BSP 115KV Line Protection (Both lines):

SET # 1








SET # 2








NOTE:


CT REQUIREMENTS:

The new line differential protection shall be suitable for used with the existing CT's at Khafji-4. It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.



The existing Khaji Sub-4 115KV breaker failure scheme, 115KV under frequency scheme shall be modified to be used with the new line protection. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.



F. KHAFJI SUB-3 SUBSTATION:





2.1 NEW AL-KHAFJI 380/115/13.8KV BSP 115KV Line Protection (Both lines):

SET # 1








SET # 2







NOTE:





CT REQUIREMENTS:

The existing CT's at Khafji-3 shall be used with the new line distance protection. It is the contractor responsibility to visit the existing substations to get all required CT information (local and remote) and provide those information along with the CT sizing calculation to PED-E for review and approval.



The existing Khaji Sub-3 115KV breaker failure scheme shall be modified to be used with the new line protection. The contractor shall be responsible for connection, modification, commissioning and all related equipment/devices etc., to accomplish the scheme as per the related attachment BFP including breaker failure transfer tripping to the other line end.

Also, the existing Khaji Sub-3breaker failure scheme shall be modified to transfer trip the LV side breakers of the Khafji-1 Transformers.



All equipment/devices required for interfacing protective relaying schemes with communication system shall be provided by the contractor. It shall be subject to approval of the company. It shall be of proven type for its reliability, dependability, security etc., and shall not be new to SEC-ERB. These equipment/devices shall be provided in each sides of the line wherever either new and/or modified protection schemes require the same. It shall have adequate number of channels. The protective relaying/communication interfacing equipment shall be separate for each set of relay-set and transfer-trip etc., such that its availability shall not be jeopardized under maintenance and non-availability conditions. Adequate number of guard signals shall be provided to avoid maloperation. In addition, codes and regenerating codes shall be provided to safeguard the signals. Adequate number of signaling channels shall be provided for various protection and transfer trip signals. The number of channels for protective relaying and transfer trips in each 115kV lines shall be as per protective relaying channel requirements stated below.

A. NEW AL-KHAFJI 380/115/13.8KV BSP - KHAFJI SUB-2 NEW AL-KHAFJI 380/115/13.8KV BSP - KHAFJI SUB-2 115KV Line [ Both Ends per each line ]:

One channel for set-1 protection line distance protection (21-1).

One channel for set-1 protection line DEF protection feature (DEF-1).



One channel for breaker failure/ Pole Discrepancy direct intertrip send/receive.

B. NEW AL-KHAFJI 380/115/13.8KV BSP - KHAFJI SUB-5 115KV Line [ Both Ends per each line ]:






C. NEW AL-KHAFJI 380/115/13.8KV BSP - KHAFJI SUB-4 115KV Line [ Both Ends per each line ]:

One channel for set-1 protection line Differential protection (87-1).


SECTION III Communication Requirement



One channel for set-2 protection line Differential protection (87-2).




D. NEW AL-KHAFJI 380/115/13.8KV BSP - KHAFJI SUB-3 115KV Line [ Both Ends per each line ]:







I. NEW AL-KHAFJI 380/115/13.8KV BSP SUBSTATION

Sequence Of Events (SOE) Recorder System

The existing sequence of event recorder(s) having adequate number of points shall be modified/expanded to include the new protections as part of SAS. Tentative /typical points list per protection is as per attachment SOE (Additional MINIMUM 20% shall be supplied as spare). All protections and equipment shall be monitored except 13.8 kV outgoing feeders for lines and auxiliary transformers.

Transient Fault Recorder (TFR)

Existing TFR recorders shall be expanded/modified to monitor the points related to set-1/set-2 of all new lines/Transfomers. If not possible, then new TFR equipment's shall be provided.

The TFR shall not be included in the Substation Automation System (SAS) and it shall have its own LAN network and it shall not be connected to the SAS Engineering PC. The connection to the TFR shall be through a dedicated TFR LAN as per the existing procedures.

II. KHAFJI SUB-5 115/13.8KV SUBSTATION


The existing sequence of event recorder(s) having adequate number of points shall be modified/expanded to include the new protections as part of SAS. Tentative /typical points list per protection is as per attachment SOE (Additional MINIMUM 20% shall be supplied as spare). All protections and equipment shall be monitored except 13.8 kV outgoing feeders for lines and auxiliary transformers.

III. KHAFJI SUB-4 115/13.8KV SUBSTATION

Transient Fault Recorder (TFR)

Existing TFR recorders shall be expanded/modified to monitor the points related to set-1/set-2 of all new lines. If not possible, then new TFR equipments shall be provided.

The TFR shall shall have its own LAN network and it shall be connected to PED PC. The connection to the TFR shall be through a dedicated TFR LAN as per the existing procedures.


SECTION IV SOE & TFR Point Lists


Existing SOE shall be modified/expanded to incorporate the addition of new line protections (including provision of additional panels, if required).

Number of TFR/SOE points shall be as per the related attachment TFR & SOE.


A T T A C H M E N T S To Protective Relaying System Requirements

SOE SOE Point List

1. Bus Differential Protection With Main & Check Zone And With CT Supervision Feature

ALARM CODE LEGEND

9 XXXKV BUS-XX DIFF 87 XXXXX MAIN ZONE PH-A OPTD * BUS SECTION ID TYPE

9 XXXKV BUS-XX DIFF 87 XXXXX MAIN ZONE PH-B OPTD *

9 XXXKV BUS-XX DIFF 87 XXXXX MAIN ZONE PH-C OPTD *

M XXXKV BUS-XX DIFF 87 XXXXX MAIN ZONE PROT TEST POSITION *

9 XXXKV BUS DIFF 87 XXXXX CHECK ZONE PH-A OPTD

9 XXXKV BUS DIFF 87 XXXXX CHECK ZONE PH-B OPTD

9 XXXKV BUS DIFF 87 XXXXX CHECK ZONE PH-C OPTD

M XXXKV BUS DIFF 87 XXXXX CHECK ZONE PROT TEST POSITION

9 XXXKV BUS DIFF 86-XXXX LOCKOUT OPTD ** CB ID

9 XXXKV BUS DIFF 74/86-XXXX SUPVN OPTD ** CB ID

M XXXKV BUS DIFF 87 XXXXX MAIN ZONE PROT ABNML TYPE

M XXXKV BUS DIFF 87 XXXXX CHECK ZONE PROT ABNML

M XXXKV BUS DIFF SCHEME 74/DC-BB LOSS OF DC

M XXXKV BUS-XX DIFF 87 XXXXX UNDERVOLTAGE ALARM *

M XXXKV BUS-XX DIFF MAIN ZONE 95 XXXXX PH-A CT SUPVN OPTD

M XXXKV BUS-XX DIFF MAIN ZONE 95 XXXXX PH-B CT SUPVN OPTD

M XXXKV BUS-XX DIFF MAIN ZONE 95 XXXXX PH-C CT SUPVN OPTD

M XXXKV BUS DIFF CHECK ZONE 95 XXXXX PH-A CT SUPVN OPTD

M XXXKV BUS DIFF CHECK ZONE 95 XXXXX PH-B CT SUPVN OPTD

M XXXKV BUS DIFF CHECK ZONE 95 XXXXX PH-C CT SUPVN OPTD


2. Numerical Differential / Distance Protection

LEGEND ALARM CODE XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-A START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-B START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-C START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-A-B START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-B-C START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PH-C-A START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX 3-PH START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX REVERSE START 2

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) REVERSE START 2

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX ZONE-1 OPTD 5



XXXXXX XXXKV LINE-X SET-X 21 XXXXXX ZONE-X OPTD** 4

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DIST XMIT* T

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DIST RECV* R

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) DEF XMIT* T

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) DEF RECV* R

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX AIDED TRIP* P

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) DEF TRIP* P

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX SOTF TRIP 7

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DIST WEAKFEED TRIP*** 1

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DIST WEAKFEED/OPEN CB ECHO*** T

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) DEF WEAKFEED TRIP*** 1

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DEF WEAKFEED/OPEN CB ECHO*** T

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PSB OPTD 6

XXXXXX XXXKV LINE-X SET-X 74/DC-X XXXXXX LOSS OF DC M

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX PROT ABNML M

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX DIST CH/FAIL* F

XXXXXX XXXKV LINE-X SET-X 67N (XXXXXX) DEF CH/FAIL* F

XXXXXX XXXKV LINE-X SET-X 21 XXXXXX LOSS OF AC OR FFR OPTD M

If only one line remove 'line-x' (applicable for all tables) * Point not required for plain distance protection ** For each additional zones/starters If DEF trip by backup time delayed trip then change the alarm code to '4' in case of plain distance scheme with backup DEF trip only. Points shall be provided for line protection CT supervision, Stub protection & broken conductor features, when used. *** Applicable for POTT scheme when weak feed feature enabled. NOTE: If a point is not related to main function of the protection then relay 'type' shall be enclosed within brackets following the ANSI device number (e.g., See points related with DEF above).

LEGEND ALARM CODE XXXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX PH-A OPTD CIRCUIT ID 9

XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX PH-B OPTD 9 XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX PH-C OPTD 9 XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX CH/FAIL F XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX LOSS OF AC M XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX PROT ABNML M

XXXXXX XXXKV LINE-X SET-X 87L-X XXXXXX LOSS OF DC M


3. Line Directional Non-Directional O/C Phase And Ground Protection Built-In Feature Of Numerical Line Protections

LEGEND ALARM CODE

XXXXXX XXXKV LINE-X PH-A 67 XXXXX DIR TOC OPTD CIRCUIT ID 4

XXXXXX XXXKV LINE-X PH-B 67 XXXXX DIR TOC OPTD 4

XXXXXX XXXKV LINE-X PH-C 67 XXXXX DIR TOC OPTD 4

XXXXXX XXXKV LINE-X PH-A 67 XXXXX DIR INST O/C OPTD 5

XXXXXX XXXKV LINE-X PH-B 67 XXXXX DIR INST O/C OPTD 5

XXXXXX XXXKV LINE-X PH-C 67 XXXXX DIR INST O/C OPTD 5

XXXXXX XXXKV LINE-X GROUND 67N XXXXX DIR TOC OPTD 4

XXXXXX XXXKV LINE-X GROUND 67N XXXXX DIR INST O/C OPTD 5

XXXXXX XXXKV LINE-X 98 FFR FOR 67 OPTD M

4. Line Tripping/Lockout Relays (As Required)

LEGEND ALARM CODE XXXXXX XXXKV LINE-X SET-1 94-1 OPTD CIRCUIT ID S

XXXXXX XXXKV LINE-X SET-1 74/94-1 SUPVN OPTD M

XXXXXX XXXKV LINE-X SET-2 94-2 OPTD S






5. Under Frequency Relay

ALARM CODE LEGEND

9 UNDER FREQUENCY 81-1 STAGE-1 OPTD

9 UNDER FREQUENCY 81-1 STAGE-2OPTD



M 74/DC-81 U/F DC SUPVN OPTD

M 74/94-1 U/F STAGE-1 TRIP RELAY SUPVN OPTD





6. Breaker Failure Protection With Single Channel I/T

ALARM CODE LEGEND

M XXXXXX BKR FAIL 74/DC-BF LOSS OF DC

9 XXXXXX BKR FAIL 62-1 STAGE-I TIMER OPTD

9 XXXXXX BKR FAIL 94BF STAGE-I TRIP RELAY OPTD

M XXXXXX BKR FAIL 74/94BF SUPVN OPTD

9 XXXXXX BKR FAIL 62-2 STAGE-II TIMER OPTD

9 XXXXXX BKR FAIL 86BF STAGE-II LOCKOUT OPTD

M XXXXXX BKR FAIL 74/86BF SUPVN OPTD

T XXXXXX XXXKV LINE-X BKR FAIL INT/TRP XMIT *

R XXXXXX XXXKV LINE-X BKR FAIL INT/TRP RECV **

F XXXXXX XXXKV LINE-X BKR FAIL INT/TRP CH FAIL *

**IF REMOTE END ALSO HAS BFP ** NOT REQUIRED IF THERE IS NO INTERTRIP REQUIREMENT

7. Circuit Breaker

ALARM CODE LEGEND

B XXXXXX XXXKV XXXXXX LINE-X STATUS CB ID EQUPTID

B XXXXXX X XXXKV XXXXXX LINE-X STATUS B OR M EQUPT ID (FOR 1 1/2 CB SCHEME)

M XXXXXX SF6 LOW PR STAGE-I OPTD (FOR SF6 CBs)

9 XXXXXX SF6 LOW PR STAGE-II OPTD (FOR SF6 CBs)

M XXXXXX MECH FAILURE STAGE-I OPTD (FOR OTHER TYPE CBs)

9 XXXXXX MECH FAILURE STAGE-II OPTD (FOR OTHER TYPE CBs)

M XXXXXX 74/TCS-1 SUPVN OPTD (FOR 1-THREE POLE CBs)

M XXXXXX 74/TCS-2 SUPVN OPTD (FOR 1-THREE POLE CBs)

M XXXXXX 74/TCS-1 PH-A SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

M XXXXXX 74/TCS-1 PH-B SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

M XXXXXX 74/TCS-1 PH-C SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

M XXXXXX 74/TCS-2 PH-A SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

M XXXXXX 74/TCS-2 PH-B SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

M XXXXXX 74/TCS-2 PH-C SUPVN OPTD (FOR 3-THREE SINGLE POLE CBs)

IF GIS SCHEME HAS DIFFERENT TYPE OF COMPARTMENT ARRANGEMENT AND HAS DIFFERENT TYPE OF TRIP BLOCK, TRIPPING, BLOCK CLOSE, BLOCK TRIP SCHEME SAME SHALL BE USED ALARM CODE SHALL BE 9 IF BLOCK TRIP OR TRIPPING IS RESULTED UPON OPERATION OF MECHANICAL/SF6 LOW ALARM ALARM CODE SHALL BE M IF INVOLVES ONLY BLOCK CLOSE


8. Pole Discrepancy Scheme (For Independent Three Single Pole CBs)

ALARM CODE LEGEND

9 XXXXXXX POLE DISCREPANCY 62-1 STAGE-I TIMER OPTD CB ID

9 XXXXXXX POLE DISCREPANCY 62-2 STAGE-II TIMER OPTD 9 XXXXXXX POLE DISCREPANCY 94PD-1 STAGE-I TRIP RELAY OPTD M XXXXXXX POLE DISCREPANCY 74/949D-1 SUPVN OPTD 9 XXXXXXX POLE DISCREPANCY 94PD-2 STAGE-II TRIP RELAY OPTD M XXXXXXX POLE DISCREPANCY 74/94PD-2 SUPVN OPTD T XXXXXX XXXKV LINE-X POLE DISCREPANCY INT/TRP XMIT R XXXXXX XXXKV LINE-X POLE DISCREPANCY INT/TRP RECV * F XXXXXX XXXKV LINE-X POLE DISCREPANCY INT/TRP CH FAIL M XXXXXX XXXKV POLE DISCREPANCY 74/DC-PD LOSS OF DC

* IF REMOTE END ALSO HAS PD SCHEME

9. 50/51 Function

LEGEND ALARM CODE

XXXXXXX XXXKV LINE-X PH-A 51 TOC OPTD 4

XXXXXXX XXXKV LINE-X PH-B 51 TOC OPTD 4

XXXXXXX XXXKV LINE-X PH-C 51 TOC OPTD 4

XXXXXXX XXXKV LINE-X PH-A 50 INST O/C OPTD 5

XXXXXXX XXXKV LINE-X PH-B 50 INST O/C OPTD 5

XXXXXXX XXXKV LINE-X PH-C 50 INST O/C OPTD 5

XXXXXXX XXXKV LINE-X GROUND 51N TOC OPTD 4

XXXXXXX XXXKV LINE-X GROUND 50N INST O/C OPTD 5

10.DEF Feature With Communication Aided Scheme

LEGEND ALARM CODE

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX DEF XMIT T

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX DEF RECV R

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX DEF OPTD P

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX DEF BACKUP TRIP 4

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX DEF CH/FAIL F

XXXXXX XXXKV LINE-X SET-X 67N XXXXXXX LOSS OF AC OR FFR OPTD M


11.High Impedance Bus Diff With CT Supervision & Without Check Zone

LEGEND ALARM CODE

XXXKV BUS-XX DIFF 87 XXXXX PH-A OPTD * BUS ID 9

XXXKV BUS-XX DIFF 87 XXXXX PH-B OPTD * 9

XXXKV BUS-XX DIFF 87 XXXXX PH-C OPTD * 9 XXXKV BUS-XX DIFF 95 XXXXX PH-A CT SUPVN OPTD * M XXXKV BUS-XX DIFF 95 XXXXX PH-B CT SUPVN OPTD * M

XXXKV BUS-XX DIFF 95 XXXXX PH-C CT SUPVN OPTD * M

XXXKV BUS-XX DIFF SCHEME 74/DC-BB LOSS OF DC * M XXXKV BUS-XX DIFF 87 XXXXX PROT TEST POSITION * M XXXKV BUS-XX DIFF 86 LOCKOUT OPTD * 9

XXXKV BUS DIFF 74/86 SUPVN OPTD * M * FOR EACH INDEPENDENT BUS SECTION ADDITIONAL POINTS AS DECIDED WHILE FINALIZING THE SCHEME BASED ON AVAILABLE OUTPUTS

12.Auto Reclosing Scheme

LEGEND ALARM CODE

XXXXXX XXXKV LINE-X 79 AUTO RECLOSER INITIATED CIRCUIT ID 2

XXXXXX XXXKV LINE-X 79 AUTO RECLOSER BLOCKED F XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER OFF * CB ID M

XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER LOCKOUT * F XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSE UNSUCCESSFUL * F XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSED * B XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER LOSS OF DC M XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER OUT OF SERVICE M XXXXXX XXXKV LINE-X 98L/79 LINE VT SUPVN AUTO RECLOSER M XXXXXX XXXKV LINE-X 98B/79 BUS VT SUPVN AUTO RECLOSER F XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER ABNML F XXXXXX XXXKV LINE-X XXXXX 79 AUTO RECLOSER IN PROGRESS B

* ONE POINT PER CB REQUIRED IN CASE OF 1&1/2 CB SCHEME

13.Bus-Tie or Bus-Section or Bus-Coupler O/C Protection

LEGEND ALARM CODE

XXXXXX XXXKV BUS TIE PH-A 51 XXXXX TOC OPTD CB ID 4

XXXXXX XXXKV BUS TIE PH-B 51 XXXXX TOC OPTD 4XXXXXX XXXKV BUS TIE PH-C 51 XXXXX TOC OPTD 4XXXXXX XXXKV BUS TIE GROUND 51N XXXXX TOC OPTD 4XXXXXX XXXKV BUS TIE 86 LOCKOUT OPTD 8XXXXXX XXXKV BUS TIE 74/86 SUPVN OPTD M

FOR BUS SECTION CHANGE BUS TIE AS BUS SECTION


14.Power Transformer Two Winding (Delta-Star)

LEGEND ALARM CODE TXXX SET-1 87 XXXXX DIFF PROT PH-A OPTD XFMR ID TYPE 8

TXXX SET-1 87 XXXXX DIFF PROT PH-B OPTD 8 TXXX SET-1 87 XXXXX DIFF PROT PH-C OPTD 8 TXXX SET-1 87REF XXXXX OPTD 8 TXXX SET-1 MAIN TANK 63 BUCHHOLZ TRIP STAGE OPTD 8 TXXX SET-1 OLTC 63 BUCHHOLZ TRIP STAGE OPTD 8 XXXX OLTC 63 BUCHHOLZ ALARM M XXXX MAIN TANK 63 BUCHHOLZ ALARM M TXXX SET-1 74/DC-1 SUPVN OPTD M TXXX SET-1 86-1 LOCKOUT OPTD 8 TXXX SET-1 74/86-1 SUPVN OPTD M TXXX SET-1 86-3 LOCKOUT OPTD 8 TXXX SET-1 74/86-3 SUPVN OPTD M TXXX SET-2 MAIN TANK PRES RELIEF OPTD 8 TXXX SET-2 OLTC PRES RELIEF OPTD 8 TXXX SET-2 MAIN TANK 26 OIL TEMP HIGH ALARM M TXXX SET-2 OLTC TANK 26 OIL TEMP HIGH ALARM M TXXX SET-2 HV PH-A 51 XXXXX TOC OPTD 4 TXXX SET-2 HV PH-B 51 XXXXX TOC OPTD 4 TXXX SET-2 HV PH-C 51 XXXXX TOC OPTD 4 TXXX SET-2 HV PH-A 50 IXXXXX NST O/C OPTD 5 TXXX SET-2 HV PH-B 50 XXXXX INST O/C OPTD 5 TXXX SET-2 HV PH-C 50 XXXXX NST O/C OPTD 5 TXXX SET-2 HV GROUND 51N XXXXX TOC OPTD 4 TXXX SET-2 HV GROUND 50N XXXXX INST O/C OPTD 5 TXXX SET-2 LV PH-A 67 XXXXX DIR TOC OPTD (FOR LV WITH DIR O/C RELAYS) 4 TXXX SET-2 LV PH-B 67 XXXXX DIR TOC OPTD (FOR LV WITH DIR O/C RELAYS) 4 TXXX SET-2 LV PH-C 67 XXXXX DIR TOC OPTD (FOR LV WITH DIR O/C RELAYS) 4 TXXX SET-2 LV PH-A 67 XXXXX DIR INST O/C OPTD (FOR LV WITH DIR O/C RELAYS) 5 TXXX SET-2 LV PH-B 67 XXXXX DIR INST O/C OPTD (FOR LV WITH DIR O/C RELAYS) 5 TXXXX SET-2 LV PH-C 67 XXXXX DIR INST O/C OPTD (FOR LV WITH DIR O/C RELAYS) 5 TXXX SET-2 LV GROUND 67N XXXXX DIR TOC OPTD (FOR LV WITH DIR O/C RELAYS) 4 TXXX SET-2 LV GROUND 67N XXXXX DIR INST OPTD (FOR LV WITH DIR O/C RELAYS) 5 TXXX SET-2 NEUTRAL 51G XXXXX TOC OPTD 4 TXXX SET-2 74/DC-2 SUPVN OPTD M TXXX SET-2 86-2 LOCKOUT OPTD 8 TXXX SET-2 74/86-2 SUPVN OPTD M

IF SUDDEN PRESSURE RELAY AVAILABLE THEN IT WILL REPLACE THE POINTS FOR BUCHHOLZ


TFR Analog & Digital Points List


BFP Circuit Breaker Failure Protection


87L Differential Protection (87L) With Distance Protection (21) And O/C (50/51 &

50N/51N) + DEF (67N) Features


DIS-21 Numerical Distance Protection Relay


DEF Numerical Directional Comparison Ground Fault Protection Relay


50/51P&N Numerical Phase & Ground Overcurrent Protection Relays


PROTECTIVE RELAY STANDARD SPECIFICATION SPECIFICATION # RPS: 87STUB

High Impedance Differential Relay - (87)

STUB PROTECTION RELAY - (87STUB)

This protection shall be used for fault protection of Tee-Off or also called as stub, an area bounded between two(2) breakers. The relay shall be based on high-impedance principle and should be designed for being stable under all external faults. The relay shall not be affected by harmonics and DC components present in the through fault currents under CT saturation. The relay shall be either voltage operated, or current operated .In case of current operated, the relay shall have external adjustable stabilizing resistor and adjustable current setting range. The stabilizing/setting resistor shall either be externally or internally mounted type depending upon type of the relay. The current range of the relay shall be 20% to 80% of rated current or equivalent in voltage calibrated relays. The ohmic value of the resistor shall be adjustable and suitable for full current setting range of the relay. The operating time of the relay shall not generally be more than 25 msec at 3 times the relay setting current. Auxiliary CT's shall not be provided in the relay either externally or internally. The CT knee point requirements, and relay setting voltage requirements including any constants (if any) shall all be furnished by the contractor along with Tender. The Contractor shall match the CT and relay application and if found unsuitable, the relay and/or CT should be changed accordingly. Non-linear type voltage limiting device or metrosil of suitable characteristics shall be provided to limit the voltage across secondary devices e.g. the relay and secondary wiring etc. to a value less than 3000 volts (peak). It shall be mounted either externally or internally. The Contractor shall provide the formula and constants of non-linear device along with tender such that its suitability should clearly be established by the Company.

"The relay shall be provided with adequate contacts for tripping, annunciation SOE, SCADA and other functions.


87T Numerical Percentage Biased Differential Protection Relay


87REF Restricted Ground Fault Protection Relay

67/67N Numerical directional Backup Phase & Ground Fault Protection Relay


LI-87BBP+BFP Low Impedance Bus Bar Differential Protection With Built-In BF Scheme


HI-87BBP Busbar Protection Relay (High Impedance Type)


95B CT Open Circuit Supervision Relay

SC-25 Synchrocheck Relay Protection


AR-79 13.8KV Automatic Reclosing Relays


CAP-59 Capacitor Bank Over voltage protection

CAP-27 Capacitor Bank Under Voltage Protection (27 + 2/27)

CAP-50/50N Harmonically Desensitized Instantaneous Overcurrent Relay


CAP-50/51P&N Capacitor Bank Non Directional Overcurrent Protection

1.1 Phase Overcurrent Protection

1.2 Neutral/Ground/Earth Overcurrent Protection


AR-79+25 Auto Reclosing With Synchrocheck Relay


UV-27 Under Voltage Load Shedding Protection (27-1 To 27-4)


UF-81 Under Frequency Relaying (81-1 to 81-4)


BIDDER FORM All Bid Proposals Shall Be Submitted In This Form

BIDDER (Name)

OFFER (Name) SUBSTATION (Name) NEW AL-KHAFJI 380/115/13.8KV BSP SUBSTATION

Relay function Bidder Proposal SMD/PED acceptance Bidder response

1 87L-1 (115KV)

2 87L-2 (115KV)

3 85-DTTR

4 87B (115KV)

5 51PH (115KV-BC/BS)

6 51N (115KV-BC/BS)

7 87T

8 87REF

9 50/51 (PH-HV)

10 50/51 (N-HV)

11 67P/N-LV

12 51G-LV

13 AVR

14 94

15 86

16 74/CB TC

17 74/94,86

18 74/DC

19 98

20 25MC

21 50/N capacitor

22 51P/N capacitor

23 64 capacitor

24 59-1 capacitor

25 59-2 capacitor

26 27 capacitor

27 13.8KV 87B

28 13.8KV 95

29 13.8KV BT 51-PH

30 13.8KV BT 51-N

31 13.8KV Feeder O/C

32 27 (13.8KV)

33 81

34 TFR

Protection SOW

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