Maintenance Schedule for Substation

OPERATION AND COMPREHENSIVE MAINTENANCE FOR SUB-STATION

ELIGIBILITY CONDITIONS

1. The firm shall have establishment and maintenance setup located at Mumbai or suburban Mumbai. The firm shall have Solvency certificate from the Bankers for a minimum of Rs. 20 lakhs, latest Chartered Accountants Certificate, valid Electrical Contractor’s licence and round the clock fixed and Mobile telephone number.

2. a) Registered Electrical Contractors of BSNL/CPWD/MES subject to their financial limits corresponding to the estimated cost of work for 12 months.

ORb) Registered Electrical Contractors of highest class in State PWD.

ANDa) Firms who have carried out satisfactorily at least 1 work (Cost of the work

shall not be less than 75% of 12 month’s estimated cost) of Maintenance in MTNL/BSNL comprising of either Sub station or Engine Alternator service as part of scope of work. Also firm's aggregate turn over for the last 3 years shall not be less than Rs. 50 lakhs reckoned from date of notice inviting tender.

1. The firm shall have following valid certificates/ registration:-

i. Sales Tax/ VAT registration certificate.

ii. EPF registration.

iii. ESIC registration.

iv. Works Contract registration number and address of WC Tax Assessing Authority as a proof of their establishment in Mumbai/ Navi Mumbai region.

v. Service Tax registration.

SUB-STATION MAINTENANCE DOCUMENT

1. Scope of Maintenance:

1.1 Ensuring that HT Panel, Transformer, LT panels, capacitor panels & out door structure as well as connecting cables/ducts, constituting the substation are maintained in healthy & clean condition,

1.2 Monitoring on continuous basis power factor & peak load and ensuring that these are maintained within limits to avoid penalty.

1.3 To perform maintenance tasks as per schedule given below.

1.4 To disconnect total electric supply and or individual loads in case of emergent situation to avoid/ limit damage.

1.5 To ensure continuous power supply and in case of breakdowns take steps to ensure restoration at the earliest.

2. Tasks to be performed within first 15 days

2.1Identify a persons(s) with necessary competence to be responsible for substation maintenance

2.2The person(s) deputed for substation job should

2.2.1 Know how to treat the persons suffering from electric shock/ burn etc.

2.2.2 Be able to operate fire extinguisher.

2.2.3 Make himself familiar with the distribution scheme the switches controlling

various loads and also importance.

2.2.4 Clearly understand what is to be done in case of an emergency. This should

be done in consultation with Engineer In-charge.

2.2.5 Carry out general inspection with a view to identify shortcoming if any in the

sub stations installation.

2.3Check all the switches & meters for proper operation

2.4Check availability and working of fire extinguishers at earmarked locations.

2.5Check operation and calibration of all the safety devices like relays and fuses.

2.6Check the earthing system for the proper earth values & continuity of earthing system.

2.7Check insulation value of oil in all the equipments.

2.8Carry out megger test.

2.9Check oil level in all the equipment to ensure proper levels.

2.10 Check power factor meter, maximum demand meter for proper functioning

2.11 Check the tripping of the HT Panel including batteries etc. for proper functioning.

2.12 Check all the electrical connections for proper tightness.

2.13 All results of above inspection to be recorded and brought to the notice of

Engineer-in-Charge specially highlighting shortcomings for necessary action.

2.14 All rectification, replacements, calibration and testing costs at the time of taking

over the maintenance at beginning shall be borne by the department.

3. Special conditions

3.1 If anything adverse is noticed during the daily check the matter will be reported to the EE (E) / DE (Bldg) and wherever necessary corrective measures should be taken immediately.

3.2 The firm shall make up any penalty on account of power factor/ maximum demand.

3.3 On receipt of breakdown call, the firm has to restore power supply immediately, not later than 8 hours, if necessary making alternate arrangement. The regular maintenance and thorough checking shall be done by the agency within 24 hours.

3.4 All materials required for repair, replacements including transformer oil should be the responsibility of the firm without any extra cost. In case of total burn out of transformer beyond repairs, department shall arrange for replacement. The decision about ‘beyond repairs’ shall rests with Engineer – in – charge. However the installation, testing and commissioning including electrical inspection shall be responsibility of the firm.

3.5 Tests are to be carried out before handing over the maintenance as per the yearly test schedule attached.

3.6 The agency will be responsible for all rectification, replacements, calibration and testing costs and hand over the installation to the new agency in healthy condition. In case the same agency continues for operation and maintenance of the installation, the agency will carryout these activities as per the maintenance schedule.

MAINTENANCE SCHEDULEFOR CAST RESIN TRANSFORMER

Sr. No.

Inspection Frequency

Items to be inspected

Inspection Notes

1 Hourly Ambient Temperature Check ambient temperature2 Hourly Winding Temperature Check WTI temperature3 Hourly Load (Amperes) Check load current4 Hourly Incoming voltage Check against rated figures

5 After every tap change/ half

yearly

HT tap links Check that links are fully tightened and locked

6 Daily WTI (Winding Temperature Indicator)WTR (Winding Temperature Relay)

Check RTD for healthinessCheck alarm & trip thermisters for healthiness

7 Half yearly Enclosure & marshalling box

(a) Check for cowebs, dust, dirt deposits

(b) Painting8 Half yearly Core & coil assembly (a) Check for cowebs, dust, dirt

deposits(b) Painting

9 Half yearly HT/ LT connections Check for tightness of nut bolts

10 Yearly Core & coil assembly Check for tightness of core bolts/ tie rod nuts

11 Yearly Earth resistance Check earth resistance

12 Yearly Transformer Check ratio (Refer to manufacturer if necessary)

13 Yearly Enclosure Side covers, cable boxes, marshalling box

14 Yearly Relays, its alarm & trip contacts, their circuits

(a) Check relays, its contacts, their operation

(b) Check alarm/ trip circuit operation for alarm

15 Yearly (or as found necessary)

Cooling fan (only for forced air cooled CRT)

Motor bearing

16 Yearly HT/LT bushings (a) Examine for dirt deposits(b) Examine for cracks/ damages

RECORD OF MEASUREMENTS FOR SUBSTATION - 3 HOURLY (BY OPERATOR)

DEPT.MV PANEL EB PANELIncomer-1 TR-1 Incomer-2 TR-2

Hou

rs

Am

bie

nt

tem

p.

Cu

rren

t

Volt

ag

e

Tem

pera

ture

Oil/

Win

din

g (

Dry

ty

pe)

Cu

rren

t

Volt

ag

e

Tem

pera

ture

Oil/

Win

din

g (

Dry

ty

pe)

PF

KW

h

KV

Ah

PF

MD

Perm

issib

le

ran

ge

85%

0f

full

load

cu

rren

t

+/-

5%

of

415

Volt

s

65 o

C (

Oil)

105°C

(D

ry

typ

e)

85%

0f

full

load

cu

rren

t

+/-

5%

of

415

Volt

s

65 o

C (

Oil)

105°C

(D

ry

typ

e)

0 .

912.00

AM 3.00 AM

6.00 AM

9.00 AM

12.00 PM

3.00 PM

6.00 PM

9.00 PM

RECORD OF DAILY CHECKS (BY OPERATOR)Month :-

X'MER HT PANEL

Date

Gen

era

l cle

an

lin

ess

Deh

yd

rati

ng

b

reath

er

Oil

OC

B t

an

k

Au

xilia

ry

fuses

Ala

rm

an

d

ind

icati

ng

cir

cu

itIn

dic

ati

ng

an

d

measu

rin

g

instr

um

en

tsBattery

(Check

for

pre

mis

es,

doors

and O

CB

etc

.)

(Check

colo

ur

of

act

ive

agent)

(Check

for

leaks

.)

(Check

for

loca

l h

eati

ng

, unusu

al sm

ell

/ nois

e)

(Check

for

healt

hin

ess

)

(Check

for

healt

hin

ess

)

(Check

for

sati

sfact

ory

opera

tion)

(Check

for

volt

age a

nd

sp

. gra

vit

y)

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

RECORD OF WEEKLY CHECKS (BY OPERATOR)

Year :- Item to be inspected :- Oil level of TransformerInspection note :- Check against oil level mark Weeks

Month 1 2 3 4 5Remark

s

January

February

March

April

May

June

July

August

September

October

November

December

RECORD OF MONTHLY CHECKS (BY OPERATOR)Year :- Months

Sl. No.

Items to be Inspected

Inspection Note JanFeb

Mar

AprMay

Jun JulAug

Sep

OctNov

Dec

LT PANEL1 Connections Check for

tightness and over heating, unusual smell or noise

2 Busbar/Cable joints

Examine insulators, busbar contacts, cable joints etc for overall condition

3 Indicating and measuring instruments

Check for satisfactory operation

4 Earthing Check for proper earthing

LT CIRCUIT BREAKER1 General

conditionsCheck for premises, doors and locks etc.

2 Connections Check for tightness and over heating

3 Load Check for load conditions and match the CT ratings

4 Busbar/Cable joints

Examine insulators, busbar contacts, cable joints etc for overall condition

5 Alarm and indicating circuit

Check for continuity and proper operation

6 Indicating and measuring instruments

Check for satisfactory operation

7 Earthing Check for proper earthing

EARTH STATION1 Earth pits Watering of pits2 Connections Tighten them

CONTACTORS1 Connections Check for

tightness of elect & mech. Joints

RECORD OF QUARTERLY CHECKS (BY AMC)Year :- Quarter

Sl. No.

Items to be Inspected Inspection Note 1 2 3 4

TRANSFORMER1 Oil Check dielectric strength (>30

KV/mm) & pH value (≥ 5.5)2 Bushing Examine for cracks and dirt deposits3 Connections Examine for looseness4 Explosion vent Examine the packing

HT PANEL1 Cleaning Remove all loose external dirt with

dry cloth2 Operating mechanisms Check for trouble free operation

3 Interlocking device Check for healthy operation4 Isolating contacts /

ShuttersCheck for proper functioning

5 Cable boxes Check for sealing arrangements for filling holes and compound for cracks

6 Insulators Check for signs of damage7 Aux. contacts/

switches/fusesCheck for any deterioration

8 Contacts Check for alignment and pressureLT CIRCUIT BREAKER

1 Cleaning Remove all loose external dirt with dry cloth

2 Fastening and clamps Check for tightness

3 Operating mechanisms Check for trouble free operation

4 Interlocking device Check for healthy operation5 Isolating contacts /


6 Arc chutes Check for carbon formation, damage etc.

7 Insulators Check for signs of damage8 Aux. contacts/ switches Check for any deterioration9 Contacts Check for alignment and pressure

10 CTs & relays Check for settings & operationLT PANEL

1 Cleaning Remove all loose external dirt with dry cloth


3 Operating mechanisms Check for trouble free operation

4 Interlocking device Check for healthy operation5 SFU/FSU Check for operation & tightness6 Isolating contacts /


7 Aux. contacts/switches Check for any deterioration

Sl. No.

Items to be Inspected Inspection Note 1 2 3 4

CAPACITOR PANEL1 Connections Check for tightness, corrosion and

breakage2 Busbar/Cable joints Examine insulators, busbar contacts,

cable joints etc for overall condition3 Indicating and

measuring instrumentsCheck for satisfactory operation

4 Capacitors Check for leakages & contacts5 External fuses Check for condition6 Insulation Measure insulation resistance

between phases and phase to earth7 Automatic power factor

relayCheck for setting and operation

OUTDOOR STRUCTURE

1 Poles Check for damages, erosion and corrosion, leaning due to overloading etc.


3 Insulators and fittings Check for cracks, flash over marks and tilting

4 Conductors and earth wire

Check for proper supports, intactness, sag, joints etc.

5 Jumpers and other accessories

Check for proper supports , clearances , proper insulation and loose joints etc.

6 Air break switch Check for proper functioning, over heating, pitting on the contacts, earth connections, locking arrangement, complete fitting of male and female contacts, arcing horns etc.

7 Lightning arresters Check for deterioration of porcelain, intactness of line and earth connection, indication of fused or spark over etc.

8 Earthing system Check for tightness CONTACTORS

1 Contacts Check for over heating marks, damage to insulation through over heating, contactor hum/chattering

RECORD OF YEARLY CHECKS (BY AMC)Sl. No.

Items to be Inspected

Inspection Note 1 2 3 4 5

TRANSFORMER1 Gasket joints Examine for tightness 2 Cable boxes Check for sealing arrangements for

filling holes and compound for cracks

3 Earth resistance Check for value, earth connections 4 Insulation resistance Check for healthiness of insulation 5 Temperature

indicationCheck pockets of thermometer

6 Paint work Check overall painting HT PANEL

1 Earth resistance Check for value, earth connections 2 CTs & PT’s Check for satisfactory functioning 3 Oil level & quality Examine for dielectric strength & oil

level in tank LT CIRCUIT BREAKER (MCCB)

1 Contacts Clean the contacts with a piece of cloth dipped in Carbon tetra Chloride and TrichloroEthyline (for corrosive atmosphere)

2 Contacts After major fault clearance, contact buttons should be cleaned with fine emery paper, after that with piece of cloth dipped in Carbon tetra Chloride and TrichloroEthyline

LT PANEL1 Rubber mats Check for condition 2 Insulators Check for signs of damage 3 Contacts Check for alignment and pressure 4 CT’s & relays Check for settings & operation 5 Insulation Measure insulation resistance

between phases and phase to earth 6 Earthing Check for earth resistance 7 Control wiring, fuses,

protectionCheck for continuity & healthiness

RELAYS/METERS/CT/PT

1 Relays Check for settings, functioning rotating mechanism etc.

2 Control wiring, fuses, protection

Check for continuity & healthiness

3 Meters Check for functioning 4 CT’s & PT’s Check for ratio 5 Insulation Measure insulation resistance

between phases and phase to earth EARTH STATION

1 Earth resistance Check for value

YEARLY TESTING OF INSTALLATION

1. Test for any sign(s) of overloading in respect of H.T. & L.T. equipments

2. Check for existence of any unauthorized temporary installation.3. Check whether the transformer oil samples are being tested

periodically and results recorded in a register.4. Check whether earth resistance is being measured periodically

and results recorded in register.5. Check where lighting arrestors have been provided near the

transformer for protection against lightning.6. Check the condition of service lines, cables, wires, circuit

breakers, isolating switches, protective recording & integrating apparatus and such other fittings.

7. Check if Danger Notice plates in the local language and of the type approved by the electrical inspector are affixed as per rules permanently in conspicuous position.

8. Check safety measures on live lines and apparatus.9. Check whether all circuits and apparatus are so arranged that

there is no danger of any part(s) becoming accidentally charged by any voltage beyond the limits of voltage for which it is intended.

10. Check if first aid boxes or cupboards conspicuously marked and properly equipped are provided and maintained.

11. Check where staff trained in first aid treatment.12. Check if instructions in HINDI, ENGLISH and MARATHI for

restoration of persons suffering from electric shock have been affixed in conspicuous place.

13. Check insulation resistance between conductors and earth in Meg. Ohms.

14. Check if all conductor and apparatus i/c live parts thereof are inaccessible.

15. Check the method adopted to guard L.V. circuits in transformer becoming accidentally charged above its/their normal voltage.

16. Check if trenches inside substation containing cable are filled with non-inflammable material or completely covered with non-inflammable slabs.

17. In case of metal sheathed electrical supply lines check whether the metal sheath connected with earth properly.

18. Check provisions made for immediate and automatic discharge of every static condenser on disconnection of supply.

19. Check every guard wire been properly earthed at each point at which its electrical continuity is broken.

ANNEXURE – I

A. Details to be supplied before starting the work

1 Name of the Agency

(with Office address):

2 Name of Proprietor/partners

:

3 Telephone No.(s)of the firm

:

4 Name & address of the Supervisor

:

5 24 Hours contact No. :

6 Particulars of the Licence/ Registration

:

B. Detail of staff to be posted at site.

Sr. No.

Name and Address

EPF no. of Operator

Annexure - II

COMPLAINT REGISTER

Sr. No.

Date &Time of

complaint

Nature of complaint

LocationTime & Date of attending complaint

Cause of fault

Material used

Dated Signature of complainant

Dated Signature of

Firm Representative

ANNEXURE – III

Programme for Periodical Maintenance for the month of __________

Name of contractor: __________________

Agreement No. : _____________________

Name of Division: _________________

Location: __________________

Sr. No.

Name of Service

Maintenance activity with

requirements of materials

Remark

(Contractor) SDE / DE

ANNEXURE – IV

Actual Periodical Maintenance carried out in the month of __________

Name of contractor: __________________

Agreement No. : _____________________

Name of Sub Division: _________________

Location: __________________

Sr. No.

Name of service

Periodical maintenance

actually carried out

Resultssatisfactory/unsatisfactor

y

Remarks

(Contractor) SDE / DE

ANNEXURE V

LOG BOOK OF SUBSTATION (INDOOR)DATE : __________

TIMEH. T.

VoltageIn KV

HT CurrentIn Amp.

Incoming

Transformer – I Transformer – II Total Power Remarks

Voltage CurrentTemp

in° C

Voltage CurrentTemp in° C

MD in

KVA

Kwh ( a)

Kvah( b )

P.F.(a/b)

RY

YB

BR

R Y B RY

YB

BR

R Y B RY

YB

BR

R Y B i) Record no. & duration of Mains failure on each day.

ii) Details of maintenance like, heating of silica gel, dehydration of transformer oil, servicing of LT. ACBs, replacement of HRC fuses, indication lamps & contacts of contactors, etc.

iii) Record of earth resistance.

08.0011.0014.0017.0020.0023.0002.0005.00

ANNEXURE VILOG BOOK OF SUBSTATION (OUTDOOR)

DATE: __________

TIME

Transformer – I Transformer – II Total Power Remarks

Voltage CurrentTemp

in° C

Voltage CurrentTemp in° C

MD in

KVA

Kwh ( a)

Kvah( b )

P.F.(a/b)

RY YB BR R Y B RY

YB BR R Y B i) Record no. & duration of Mains failure on each day.

ii) Details of maintenance like, heating of silica gel, dehydration of transformer oil, servicing of LT ACB’s.

iii) Record of earth resistance.

08.0011.0014.0017.0020.0023.0002.0005.00

Note: 1. Log book shall be checked daily by the Technician/JTO in- charge.2. Log book shall be checked and reviewed by SDE in-charge at least once in a week.3. Log book shall be checked and reviewed by DE in-charge at least once in a fortnight.

Maintenance Schedule for Substation

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