Power Transformer 115kV/12.47kV Web viewThe tank cover shall be domed and external features shall be...

ATTACHMENT E MATERIAL SPECIFICATION FOR TRANSFORMER #1

1.0 SCOPE This material specification covers oil-immersed 12/16/20 and 20/27/33 MVA 3Ø, 117.875-12.47 kV, two winding, LTC power transformers in accordance with the following descriptive specifications.

2.0 NATIONAL STANDARDS The power transformers shall be manufactured, tested, and furnished according to the latest edition, revision or amendments to the applicable standards of ANSI, NEMA, and IEEE except as specifically noted in this specification. The equipment is required to meet OSHA standards.

3.0 MODIFICATIONS TO REFERENCE STANDARDS

3.1 Ratings General Ratings: The power transformer shall be outdoor, three-phase, two winding 60Hz, 65° C temperature rise, 80° C hot spot winding temperature rise with FR3 fluid for operation at an elevation up to 3300 feet rated:

1. 12/16/20 MVA and 117.875-12.47 kV or

2. 20/27/33 MVA and 117.875-12.47 kV.

The transformer shall be rated on ONAN/ONAF/ONAF or ONAN/ONAF/OFAF basis. The windings shall be connected Delta on the 117.875 kV high side and Wye on the 12.47 kV low side for use on a grounded Wye system. The angular displacements between the high voltage and low voltage windings shall be 30° lagging as shown below. The polarity of the transformer shall be subtractive.

MATERIAL SPECIFICATIONEUGENE WATER & ELECTRIC BOARD - EUGENE, OREGON

POWER TRANSFORMER 115 kV / 12.47 kV

August 14, 2015 REV. ES3-9.130 12PAGE 1 OF 42


Basic Impulse Level: The 117.875 kV high voltage winding shall have a BIL withstand rating of 450 kV. The 12.47 low-voltage winding including the neutral shall have a BIL withstand rating of 110 kV.

3.2 Transformer Impedance The impedance H to X shall be:

1. 6.0% on a 12 MVA base for 12/16/20 MVA transformers,

2. 10.0% on a 20 MVA base for 20/27/33 MVA transformers.

3.3 Construction The transformer shall be constructed of only the highest quality materials. All insulation material shall be of the thermal upgrade type. All blocking material shall be high-density transformer board, Weidmann, Type TX2 or EWEB approved equal.

The manufacturer shall be able to demonstrate during the design review, the design of the insulation system employed through finite element methods. An acceptable demonstration would be the static voltage plots for each of the windings.

The coils will be disc or helical type, pre-sized, clamped, and braced to provide adequate short-circuit strength. The Bidder shall submit a drawing or picture showing the coil bracing system to be used in the transformer. The manufacturer shall supply calculations for the maximum stresses for different fault conditions and tap positions as requested by EWEB. The inner winding buckling stress shall be specified for both the free (unsupported) and forced (supported) buckling. In addition, calculations for all buckling, loop, radial bending, axial bending, tipping and radial spacer stresses for all windings in all tap positions. The maximum axial forces and the withstanding capability of the end support shall be supplied prior to design review.

Vertical clamping force shall be uniformly applied to the entire horizontal surface of the one-piece upper and lower pressure plates. All windings shall have full-circumference clamping. Partial circumference block between the full-circumference pressure plate and the top and bottom frames shall not be allowed. The inter winding straps (flinch plates) tying the upper and lower support frames together shall be stainless steel. Any manufacturer that uses jacking bolts as a standard design will not be considered. Any system using jacking bolts to apply pressure to the coils shall not be allowed.





The ampere turns per unit height of all windings including, but not limited to, high voltage, low voltage, and regulator windings, shall be equal from the top to the bottom of the winding. Rectangular winding shall not be allowed. Only round windings with copper conductor shall be allowed.

Upon the request of EWEB the Bidder shall submit a drawing showing the coil winding and interconnections of the type shown below. (The drawing is only to show the type of drawing required and does not indicate that this type of winding configuration is necessarily preferred by EWEB.) The crossovers between discs and other bends in the magnetic wire shall be wrapped with additional insulation. All bends in the magnetic wire for connections to leads shall be minimized to the maximum extent possible.

When the winding of the coil is complete and prior to assembly on the core, the coil will be pre-sized. The pre-sizing process will consist of drying the individual coils; and then the individual coils will be pre-sized by hydraulically pressing the coil to the calculated pre-loading stress to determine the height of the coil. All coils will be sized to the same height. Preference will be given to a manufacturer that individually dries the coils via the vapor-phase process and impregnates the coils with insulating fluid while the coils are under full vacuum.

The core shall be circular, built with the highest quality grain-orientated silicon core steel. The core shall be designed so that the flux density does not exceed 1.7 Tesla at 110% of nominal voltage. Core laminations shall not exceed 0.012 inches in thickness.





The manufacturer shall employ burr detection and mitigation such that the maximum burr height does not exceed 30 microns. The core shall be epoxy-coated to help reduce the noise level of the transformer. Each layer of the core steel shall be sequentially cut and stacked in the same order as the core steel is cut. The top and bottom yokes of the core shall be single sheets of steel that run the full length of the yoke to minimize the number of joints in the core. Scrap-less mitered cores shall not be allowed.

The core will be supported with a combination of epoxy and blocks of high-density and high-temperature material. The insulation between the core and the end frames to support the core laminations and distribute the top and bottom frame pressure must be blocks of high-density and high-temperature material. Double nutting shall be used for all bolts in the clamping structure for the core and coil assembly.

The manufacturer shall photographs the core and coil assembly prior to tanking. Photos shall show all sides of the core and coil assembly including a top view. These photos shall be provided to EWEB for review and included in final documentation.

3.4 Internal Connections All connections of winding to lead shall be made by brazing or full-circumference crimp connection wrapped with foil-faced tape. All power leads shall be routed through high-density tubing for straight runs of distances greater than 12 inches. All leads shall be rigidly clamped within a lead support structure that fully supports the weight of the leads and the forces exerted on them during a short-circuit condition. Leads shall not be attached to the inter-phase barriers.

Lead support structures shall be attached to end frames on supports welded to the end-frames. No studs shall be shot on the end-frames without full welding around the perimeter of the stud. No ties of nylon or other plastic material shall be used. Lead bolts shall be epoxy-locked or use two nuts on each to ensure against loosening. No black iron or steel bolts shall be used.

3.5 Internal Frames and Bracing The core-and-coil assembly shall be positively located in the bottom of the tank. The top frame of the core-and-coil assembly shall be bolted to all four-tank walls or braced to all four-tank walls and the transformer cover to prevent movement in both the vertical and horizontal directions. Slotted bolt holes shall not be employed. No welding will be allowed in the tank once the core-and-coil assembly is placed in the tank.

3.6 Core Ground





An external core ground shall be furnished by means of an insulated cable brought up to a suitable bushing on the tank cover or near the top of the tank wall with a removable strap located between the bushing terminal and tank. The bushing shall be rated not less than 5 kV, and located and labeled to avoid confusion with other bushings. The transformer shall be shipped with this bushing installed.

3.7 Transformer Drying The core-and-coil assembly shall be dried via the proper vapor-phase process. The maximum elapsed time between removing the core and coil assembly from the vapor phase changer and pulling vacuum on the sealed transformer tank shall not exceed 8 hours. If the 8-hour exposure time is exceeded, the manufacturer shall pull a vacuum of 50 microns or less for a period of 4 hours for each hour or portion thereof that exceeds the 8-hour exposure time.

3.8 Tank All tanks shall be made of steel. The tank, including the radiators and accessories, shall be designed for a maximum pressure of 15 psig and to withstand a full vacuum, including the barrier between transformer and the LTC tank. The tank wall reinforcement shall be fully enclosed with all seams, joints, and end plates continuously welded on flat surfaces of the tank. All tank seam welds shall fully penetrate to the inside of the tank. Only stainless steel studs shall be used on the tank and the studs shall be completely welded around the perimeter of their base. All nuts, washer, and lock washers shall be silicon-bronze, or brass.

Transformer shall be sealed tank type with welded cover. During welding of the transformer cover, an inorganic gasket will be permanently located between the cover and the tank flange to prevent weld spatter from entering the tank. Covers on all manholes and inspection openings shall be bolted on. All bushings shall be bolted on. The transformer must be designed for full vacuum filling.

The tank cover shall be domed and external features shall be designed to prevent the collection of water. Doming the tank cover by flexing and welding it to the main tank or any other means that places stress on the cover weld or mail tank shall not be allowed, except where the top frame of the core-and-coil assembly is rigidly connect to the transformer cover. All external devices that are connected to the top of the transformer via a gasketed connection shall have the collar continuously welded to the top of the tank. All gasketed surfaces shall be provided with gasket recess and gasket compression-limit stops. All gaskets in contact with oil-bearing surfaces shall be nitril (Buna-N or TG-65) rubber.





The completed tank shall be tested at 10 psig for a period of 24 hours without any change in pressure to ensure the tank can hold the maximum pressure. During this test the tank will be equipped with a Qualitrol or equal pressure relief device with a minimum actuation pressure of 15 psi (for a Qualitrol model 208 or 213 this would mean a nominal pressure rating of 17 psi). If the manufacturer elects to perform this test with transformer oil-filled, the head space will be pressurized at 10 psig and the pressure on those portions of the tank below the oil level will be 10 psig plus the head pressure of the oil. The transformer shall be completely assembled during this test including all radiators, fans, pumps, bushings and all other accessories supplied by the manufacturer including lightning arrestors, if applicable. Test results shall be documented and included in final testing report to owner to review.

The tank shall be fitted with a Qualitrol model XPRD (Extra Protection Relief Device). The pressure relief device shall be set at 10 psig and the vent pipe shall be designed to prevent oil from spraying out on the transformer or other equipment, and shielded to inhibit animal access. Alarm contacts on the pressure relief device shall be wired to the control cabinet terminal blocks.

3.9 Bushings High-voltage line bushings will be located on the transformer cover in ANSI Segment 3. All high-voltage bushings shall be of the transformer draw-lead type with a minimum current rating of 800 amperes. The high voltage bushings shall be physically interchangeable with circuit breaker bushings of the same BIL rating.

The high voltage bushings shall be constructed of oil-impregnated paper and shall be on the condenser principle. Bushing shall be a fiberglass tube construction with flexible silicon rubber sheds or similar material that is hydrophobic, resists UV radiation, and resists ozone All bushings shall have a voltage tap for power-factor testing. All high-voltage bushings shall be liquid-filled with liquid level indication visible from the ground and have a 550 kV BIL rating and a minimum creepage based on the latest revision of IEEE C57.19.100, “Medium” contamination level, at the nominal voltage.

Three (3) LV phase bushings and one (1) LV neutral bushing shall be located on the transformer cover in ANSI Segment 1.

The low-voltage and neutral bushings shall have a minimum current rating of 2,000 amperes and shall be bottom-connected. The low voltage bushings must have a 150 kV BIL rating. Bushings are to be Pcore catalog number 89123-70 or EWEB approved equal.





All bushings shall meet all requirements of the latest ANSI Standard C 76.1 for bushings for power circuit breakers and outdoor transformers. All bushings shall be ANSI 70 Light Gray in color. Provide a NEMA standard four (4) hole stud connector on each bushing with appropriate current rating for bushing capacity.

All bushings and their associated mountings shall be suitable for washing by a stream of water under high pressure when the transformer is energized without admitting water into the bushing or the transformer, regardless of the angle at which the stream of water impinges on the bushing or the associated mounting.

3.10 Parallel Operation The transformer shall be capable of being operated in parallel with a similar unit by use of the circulating current method. This requirement shall be met with the use of the Reinhausen Tapcon 250 tap changer control specified in paragraph 3.14. EWEB reserves the right to require paralleling information at any time.

3.11 De-Energized Tap Changer (DETC) A DETC shall NOT be required.

3.12 Lightning Arresters All lightning arresters shall be gapless station class with polymer housings. The low-voltage arresters shall be Cooper catalog number UX00900749A11 and the high voltage arresters shall be Cooper catalog number UX09607649A11 or EWEB approved equal.

The manufacturer shall provide the three (3) high-voltage arresters rated 96 kV and three (3) low-voltage arresters rated 9 kV.

The top of the NEMA four (4)-hole connector at the top of the arrestor is to be at the same height and centerline as the NEMA four (4) hole connector of the associated bushing. All lightning arresters shall be gray in color.

The mounting brackets shall be drilled with three (3), 5/8-inch diameter holes on a 10-in bolt circle A line between two of the holes shall be perpendicular to the tank wall.

The manufacturer shall also include a minimum 1/4”x2” copper bus bar for grounding the arresters. The lightning arresters shall be double-grounded with each end of the copper bus bar terminating at a separate ground pad at the base of the transformer. The copper bus bar shall be attached to the transformer at a minimum of every 24 inches. The copper bus bar shall be routed such that the neutral bushing can be connected to the bus bar with





a minimum amount of 4/0-stranded copper. Additional copper bus should be installed to connect HV arrestor ground bus with LV arrestor ground bus. The copper bus bar shall attach at all four (4) corners of the transformer to a NEMA ground pad in a way that allows for EWEB to connect station grounds to the copper bus bar as shown in EWEB standard EC3-6.0501.

3.13 Current Transformers Provisions shall be made to allow for the mounting of two (2) bushing-type multi-ratio current transformers in each of the 115 kV and 12.47 kV bushing wells.

The transformers shall be supplied with the bushing type current transformers specified below:

Terminals Full-Winding Amperes Relay Accuracy Rating

FactorH1, H2, H3 600 C400 2.0H1, H2, H3 600 C400 2.0X1, X2, X3 N/A N/A N/AX1, X2, X3 N/A N/A N/A

X0 1200 C400 2.0

The current transformers shall be of the 5-lead type with ratios as listed in ANSI C57.13-1968 Table 8. All taps for each current transformer shall be connected to a GE type EB27B06S shorting-type terminal located in the control cabinet for customer use. All wiring between the CT terminal boxes and the control cabinet shall be in rigid conduit.

All the current transformers specified above are in addition to the necessary current transformers as required for the specified accessories.

3.14 Load Tap Changer The transformers shall be supplied with a three-phase automatic-manual load tap changer designed to regulate the 12.47 kV winding plus and minus 10% of the rated voltage in thirty-two 5/8% steps.

The transformer shall be capable of supplying ONAF or OFAF kVA rating when the load tap changer is on any position at, below, or above rated secondary voltage. The tap changer shall be of vacuum-diverter reactive design. The Bidder shall list in the Proposal





section, the type and electrical rating of the tap changing equipment the Bidder will provide.

Approved LTC mechanisms are the Reinhausen Type RMV-II.

If a booster transformer is required to reduce the current level to the LTC, the booster transformer shall be of the same design and construction as the main core-and-coil assembly, including short-circuit withstand capability. Preference shall be given to designs that do not include a booster transformer.

Each tap of the regulating winding shall be fully distributed over the entire coil height and wound such that the amp-turn per height ratio of the high-voltage winding, the low-voltage winding and each tap of the regulating winding are equal.

All arcing contacts of the tap changer shall be in a separate compartment. The compartment shall be oil-filled with a liquid-level gauge and a sudden-pressure relay and the associated seal-in relay located in the control cabinet with a contact that closes if there is an unusual pressure rise within the load tap changer compartment. In addition, the tap changer compartment, together with the barrier between the LTC compartment and the main tank shall be able to withstand a full vacuum while the main tank is at atmospheric pressure.

The tap changer shall have a direct-driven position indicator, with electrically resettable drag hands. The position indicator shall be easily read from the ground without opening any doors. Any control cabinets required for the LTC shall meet the requirements of paragraph 3.19 of this specification as applicable.

The tap changing compartment shall be supplied with a Qualitrol model XPRD (Extra Protection Relief Device). The pressure relief device shall be set at 10 psig and the vent pipe shall be designed to prevent oil from spraying out on the transformer or other equipment, and shielded to inhibit animal access. Alarm contacts on the pressure relief device shall be wired to the control cabinet terminal blocks.

The Reinhausen Tapcon 250 load tap changer control together with the separate “First House Voltage Protector,” a Beckwith M-0329B, shall be mounted in the control cabinet. The load tap changer control shall be complete with the TC250-80 Adaptor Panel and meet all of the following operational requirements:

1. Paralleling equipment shall be of the circulating-current type, selectable with a selector switch.





2. The LTC control shall be furnished with the following:

A. Remote / Local Selector Switch

B. Auto / Manual Selector Switch

C. Raise / Off / Lower Momentary Switch

D. Paralleled / Independent Selector Switch

E. Voltage Source Internal / External Selector Switch

F. Voltage Test Terminals

G. Test Terminals for energizing the control circuits from an external source with a disconnecting device for de-energizing the LTC controls. The disconnecting devices shall open the control circuit from the potential sources and short/isolate the internal current transformers from the control circuit.

H. Customer usable contact wired to terminal blocks for remote indication of auto/manual status of LTC controller.

3. Terminal blocks shall be provided in the control cabinet for connecting EWEB SCADA contacts as listed below:

A. SUP/M

B. SUP/A

C. SUP/Raise

D. SUP/Lower

4. LTC control shall be wired according to EWEB standard drawing, ED3-5.2001

5. The manufacturer shall provide a 4-20mA output for LTC tap position indication. A separate contact output shall indicate “on-tap/off-tap” position. All contacts shall be wired to a suitable terminal block in the control cabinet for connection to EWEB’s SCADA system.

6. The current transformer (CT) for the line drop compensator shall be located on bushing X1. Line drop compensator auxiliary CT’s shall be rated 5/0.2A. The current transformers specified herein are not included in Section 3.13.





7. An isolating transformer with ratio 1:1 shall be furnished in the 120V LTC control potential input circuit. EWEB will furnish the necessary 7200/120V line to neutral or 12470/124.7V line-to-line potential transformer for LTC control.

8. Overload protection and disconnecting devices for tap changer drive motor circuits and line drop compensator circuits shall be provided.

9. A hand crank mechanism shall be provided to manually operate the tap changer, interlocked with the electrical system so that when the manual handle is used, the motor is disconnected from its source. The interlock must show a visible break in the motor circuit.

10. The current and potential circuit for the load tap changer control shall be electrically isolated from the 120/240V, single-phase, auxiliary power source.

11. The load tap changing drive motor and all necessary control relays shall be capable of operating from a 120/240V, single-phase, 60 Hz three-wire source.

12. Vacuum bottle interrupters shall include complete integrity controls.

13. Over current blocking controls to protect the tap changer from operating when load current is beyond the tap changers rating.

14. The LTC controller shall be furnished with a serial communications port and a multi-mode fiber optic port.

15. The LTC control shall support the DNP3 protocol.

16. Furnish and install the following LTC control accessories:

A. Tap changer operation counter

B. Neutral indicating light on the control panel

17. The tap changer compartment shall be equipped with the following accessories:





A. Internal motor power supply and terminals for external motor power supply.

B. Oil drain valve, sampling device and filter press connections.

C. The load tap changer compartment breather will be equipped with maintenance-free silica gel breather. The maintenance-free breather will contain 600 grams of silica gel desiccant that is automatically dried once every two weeks. The auto-recharging dehydrating breather system shall be a Waukesha Electric type ARDB.

3.15 Auxiliary Power Source Manufacturer shall provide terminals in the control cabinet for customer connection of 120/240V, single-phase, three-wire source and 125VDC ungrounded two-wire source.

EWEB will provide 120/240Vsingle-phase, three-wire, 60 Hz source for operation of all transformer auxiliaries, including the cooling equipment. The manufacturer shall provide an AC load schedule or recommend circuit size for AC service to transformer.

EWEB will provide 125VDC ungrounded two-wire source for DC control voltage.

3.16 Cooling Equipment The transformer shall be designed for continuous self-cooled operation. The self-cooled top oil temperature rise by resistance shall not exceed 65° C, and hottest spot winding temperature rise shall not exceed 80° C, when cooled with FR3 fluid. The manufacturer shall demonstrate the capability to model transformer heating using FR3 and provide this model/calculations upon request.

The transformer shall be capable of being loaded continuously to:

1. 12,000 kVA self-cooled and 20,000 kVA with two stages of forced cooling

2. 20,000 kVA self-cooled and 33,000 kVA with two stages of forced cooling

without exceeding the specified temperature rise. Such operation shall be available without any decrease in the normal life expectancy of the insulation.

The complete transformer, including external components (bushings, etc.), as well as internal components, shall be suitable for overload operation in accordance with ANSI C57.92, NEMA TR-98, and IEEE 5071D5.





Cooling class of transformer with self-cooled rating only shall be ONAN. Cooling class of transformer with self-cooled rating and two forced-cooled ratings shall be of ONAN/ONAF/ONAF or ONAN/ONAF/OFAF.

The cooling equipment shall be controlled by winding hot-spot temperature, manual control switches in the control cabinet, and by transformer monitoring equipment. Winding temperature equipment shall be furnished as follows (necessary current transformers shall be in addition to the current transformers in paragraph 3.13).

1. Each set of equipment specified shall include a dial-type temperature-indicating relay with four (4) adjustable contacts each. Dial indicator design, and mounting arrangement shall permit reading from ground level near the transformer. All gauge contacts shall be wired to terminal blocks in the transformer control cabinet.

2. Two sets of temperature gauges with temperature indicating relays will be used; one indicating top oil temperature and one indicating hot spot temperature. Settings for the temperature indicating relays shall be as follows:

Top oil relay shall be set at 75°C, 80°C, 100°C and 110°C.

Winding relay shall be set at 75°C (Stage 1 cooling), 80°C (Stage 2 cooling), 110° (alarms) and 130°C (trip).

3. The radiators shall be galvanized panel-type and all radiators shall be removable. In conjunction with removable radiators, manufacturer shall furnish suitable valves on the transformer side of the radiator mounting flanges, and top and bottom pipe taps with plugs (minimum 1/2-inch) on the radiators, to permit draining and removal of the radiators without draining oil from the transformer tank. All shutoff valves shall be easily accessible with all the radiators in place. Removable radiators shall be equipped with lifting eyes, and so designed that they can be handled without the addition of special bracing. Provide a separate oil-tight blank flange for each radiator connection for use when the radiator is removed and during shipment. Ensure adequate space for radiator removal assuming there will be a fire wall between adjacent units four (4) feet higher than the highest oil containing component on the transformer e.g. high voltage bushing, conservator, etc and approximately eight (8) feet from any radiators mounted in Segment 2 or Segment 4 of the transformer.





4. For transformer cooling that includes oil circulation pumps, oil flow indicator with alarm contact shall be furnished for each pump to indicate low oil flow when pumps should be running. Oil pumps shall be located near foundation level; manufacturer shall furnish suitable valves on both sides of each pump and pipe tap with plug (minimum 1/2-inch) at the lowest point on the pump section between the valves, to permit draining, removal, and reinstallation of pump without draining oil from the radiators or the transformer tank. The power supply to pumps shall not be made through connectors, which must also seal the oil system.

5. Cooling fans shall be located only on the sides of the radiators to provide maintenance accessibility with adequate safety clearances from transformer live parts. The fan guards are to be stainless steel or hot-dipped galvanized and shall meet all OSHA requirements, including that a 1/2-inch diameter rod shall not penetrate the guards. Provide a sufficient number of low-speed propeller-type fans to allow any one cooling fan to be taken out of service without exceeding top oil temperature rise limits while operating at rated load. Fan blades to be one-piece cast aluminum or stainless steel. All fan motors are to be totally enclosed with plug/receptacle cord connections. Fan motors shall be equipped with double sealed, grease-lubricated ball bearings and shall not require lubrication during the life of the motor.

6. The mounting hardware for all cooling and any cooling related equipment including, but not limited to, fans, radiators, radiator bracing, radiator pumps, flow indicators and flexible connectors, valves, shall include flat washers, lock washer, and nuts.

7. A 100 ohm platinum resistance temperature detector (RTD) shall be installed in a separate tank well, with a load current biasing heater similar to that employed in the hot spot gauge. The RTD signal shall be input directly to the Transformer Monitor (SEL-2414). RTD’s shall be easily replaced without removing any additional components.

8. An auxiliary relay shall be furnished to provide alarm indication for loss of power to the cooling equipment with a 30-second time delay to avoid alarming for momentary loss of power.

9. Cooling control relays shall remove electrical power from the “high” side of the cooling equipment loads. The manufacturer shall also furnish all





necessary wiring, labeling and terminations between the cooling equipment and equipment in the control cabinet (paragraph 3.19).

10. All cooling equipment shall be free from any and all undue or harmful vibration.

11. The cooling fans shall be operated from contacts on the temperature gauges, manual control switch in the control cabinet, and from the transformer monitor equipment in the control cabinet as programmed by EWEB. The gauge settings are discussed in section 3.16 point #2. The manual control switch shall have OFF, AUTO, and MANUAL settings independent for each stage of fans; OFF removes control power from the specific group of fans, AUTO enables control power and allows the gauge or transformer monitor to govern operation and MANUAL operates the group of fans continuously. The transformer monitor shall be connected to the fan control circuits as shown in the EWEB standard drawing but shall be programmed by EWEB.

3.17 Oil The transformer tank will be supplied and filled with new natural ester fluid, Cargill Envirotemp FR3. Residual natural ester fluid shall be shipped in 50 gallon barrels or other shipping containers as approved by EWEB.

The transformer tank shall include a weather resistant sign specifying that the transformer has been designed for and filled with FR3 insulating fluid. Additionally the nameplate shall specify that the unit was designed for and filled with FR3 insulating fluid.

The FR3 oil supplied with the transformer shall be handled in accordance with the latest revision of Cooper Power Systems Bulletin 97080.

The LTC tank will be supplied and filled with new mineral oil inhibited against oxidation prior to shipping with 0.3 percent by weight of DBPC. Residual oil shall be shipped in 50 gallon barrels.

All the mineral oil supplied to properly fill the transformer shall not be contaminated with other substances and the manufacturer shall certify that the oil contains less than one (1) ppm of polychlorinated biphenyls (PCBs). In addition, the manufacturer shall state on the nameplate, “The transformer contains less than 1 ppm of PCBs.”





The mineral oil supplied with the transformer shall be in accordance with ASTM D3487 “Standard Specification for Mineral Insulating Oil Used in Electrical Apparatus.”

If the transformer is shipped with dry air or nitrogen, the oil shall be delivered on date and time, as specified by EWEB.

3.18 Oil Preservation System The oil preservation system shall be a positive pressure system and designed so that oxygen is excluded from the preservation system. EWEB may specify one or the other preservation system (Nitrogen Pressure or Conservator Oil Preservation System) as part of specific requests for quotation.

1. Nitrogen Pressure: A nitrogen gas pressure system shall include a 200 cubic ft gas cylinder installed in a stainless steel cabinet mounted on the transformer tank with the bottom of the enclosure not more than 2” above the bottom of the transformer base; a three stage pressure regulating system; and a pressure-vacuum gage, pressure relief valves, and alarm contacts to indicate high and low transformer gas pressure and low nitrogen cylinder gas pressure. A valve for purging the gas space shall be provided. Purging fitting shall be tapped into opposite side of transformer tank from nitrogen gas inlet. The full nitrogen cylinder installed in the cabinet shall become the property of EWEB.

2. Conservator Oil Preservation System: A conservator oil preservation system shall include an expansion tank and a nitrile or urethane air cell vented to outside air through an auto-recharging, dehydrating breather system. The maintenance-free breather will contain 600 grams of silica gel desiccant that is automatically dried based upon an adjustable schedule of daily to once every two weeks. The auto-recharging, dehydrating breather system shall be a Waukesha Electric type ARDB. One expansion tank is preferred, located on either end of the transformer (per ANSI C57.12.10 Segment 2 or Segment 4). The air cell shall be designed for flange installation (clamps not allowed), and shall prevent contact between oil in the expansion tank and the air. The expansion tank shall be of sufficient volume to operate through an ambient temperature range of -40° C to +50° C without causing the low oil level alarm contacts to close at the lower limit, and without exceeding the recommended full oil level at the upper limit. An air cell failure relay shall be furnished to provide an alarm for the conservator system when it detects a bladder leak. The auto-recharging dehydrating





breather system shall be located so it can be safely maintained with the transformer energized. A Buchholtz-type relay shall be furnished, equipped with two float mechanisms that contain two normally open contacts, one associated with each float. The petcock furnished on the Buchholtz relay for taking samples and releasing gas from the top of the relay housing shall be located in the same segment as the control cabinet and located that samples may be taken 4 feet above ground level.

Provision shall be made for testing the relay operation without removing the relay from the transformer. The relay shall be readily removable for maintenance purposes without draining oil from the conservator or the transformer. The relay shall be provided with an external device to operate the switch contacts and thereby test the contact operation together with the circuit continuity of the relay. Suitable valves shall be furnished in the oil line between the expansion tank and the main transformer tank, one valve on each side of the Buchholtz-type relay. A by-pass valve shall also be furnished. All of the valves between the main tank and the expansion tank shall be vacuum tight. A temporary pressure-vacuum gauge shall be furnished for monitoring the pressure in the main transformer tank during shipment.

3.19 Control Cabinet

1. The control cabinet shall be a stainless steel NEMA 4 enclosure. Doors shall be gasketed, continuous hinge with a 3-point door latch operated by a single handle. Interior swing panels shall be included to accommodate panel mount equipment and provide access to back panel wiring and equipment. The cabinet shall be furnished with cooling equipment control devices, LTC equipment control devices, customer specified transformer monitor, and terminal blocks for terminating all auxiliary wiring and shall be mounted on Segment 1 wall of the transformer tank. The cabinet shall be furnished with two heaters, one that operates continuously and one heater that is thermostatically controlled, or an EWEB approved alternative heating system. All thermostats shall be adjustable from 45 F to 90 F. The control cabinet shall be supplied with screened vent openings with fiberglass dust filters in order to avoid condensation within the cabinet. EWEB will bring all external auxiliary power and control wiring in conduit to this cabinet. This cabinet shall be furnished with removable bottom plate(s) for drilling by EWEB. These plate(s) shall be supplied with





gasket(s) to provide a weather tight connection. Controls, terminal blocks, and other devices requiring access for operation and maintenance shall be mounted in the compartment at a height less than six feet above foundation level. The door swing shall be limited to 36” and feature a maintenance free locking mechanism that will keep the door open after opened beyond a certain point.

2. All auxiliary power and control wiring shall consist of highly stranded copper, SIS, switchboard wire, 600V class, with insulation (or outer covering over the insulation) that is flame-retardant and heat, oil, and moisture retardant. Where possible, wiring inside the control cabinet shall be run in plastic wire duct with covers. Where it is not possible to contain the wiring in the duct, the wiring shall be wrapped with plastic spiral binding. Wire bundles crossing hinges shall be spiral bound and securely clamped to both the door and the cabinet, and run parallel to the hinge for at least half the door length. The plastic duct and spiral binding shall be manufactured by the Panduit Company, Hoffman, or EWEB approved equal. Wiring runs outside the control cabinet shall be in RGS conduit except for short, flexible leads from conduit boxes to fans, pumps, and relay and alarm devices, which may be in seal-tight conduit or weatherproof cable; each of these leads shall be furnished with a separable, weatherproof connector. Both ends of all wires and all terminal block points shall be clearly marked with the designation shown on the manufacturer’s wiring diagrams. No control circuit shall be spliced. All installed conduits shall be oversized by 25% to allow for future expansion.

3. All devices shall be identified with permanently attached labels, which correspond to the wiring drawing provided by the manufacturer..

4. The control cabinet shall contain terminal blocks for terminating all auxiliary equipment wiring, wiring from the cooling equipment, all alarm and relay contacts and all current transformer secondary leads.

5. Alarm and relay contacts shall be normally open, ungrounded. Both sides of each contact shall be isolated from all other contacts and independently wired to the control cabinet.

6. All auxiliary relays supplied or installed by the manufacturer shall be Square D Type X, or EWEB approved equal.





7. All cabinet doors shall be provided with door pockets large enough to accommodate a 3-inch wide three-ring binder. In addition to the items mentioned above each door shall control a light inside the control cabinet and the control cabinet shall contain a 20A non-GFCI duplex outlet.

8. Control circuit wire size shall not be less than 12 AWG except when wiring to customer-specific devices that will not accept 12 AWG. In this case, the largest wire size the device will accept shall be used. All control circuit wiring shall be terminated with un-insulated ring-type terminals except for devices which will not accept a ring-type terminal. All power circuit wiring shall be sized and protected for the current and voltage required.

9. All current transformer secondary wiring shall be 10 AWG with un-insulated ring type terminal connectors. Each CT shall be individually grounded inside the control cabinet.

10. Adequate space shall be provided around all devices and terminal blocks to allow for the removal, installation, and termination of all incoming wiring. No more than two (2) wires shall be landed under any one terminal screw. The manufacturer shall provide an additional ten percent (10%) of spare terminals. A 10-inch high by 10-inch wide by 8.5-inch deep space shall be reserved on the backplane of the control cabinet for future equipment to be installed by EWEB.

11. All terminal blocks shall utilize #10 screws with 32 threads per inch and shall be General Electric-type EB-25, with the exception of current transformer terminal blocks, which shall be General Electric-type EB-27.

12. The control cabinet shall be completely assembled and wired at the time of delivery.

13. A fiber optic patch panel shall be mounted to the main backplane of the control cabinet to facilitate fiber optic communications between the substation control house and the transformer control hardware. The fiber optic patch panel shall be Corning Single Panel Housing model SPH-01P and be equipped with Closet Connector Housing model CCH-CP12-15T. EWEB shall furnish all fiber optic cables. The fiber optic patch panel should be mounted in a way and location that limit the bends required by the fiber optic cable through the control cabinet.





14. A 100 ohm platinum resistance temperature detector (RTD) with protective guard shall be mounted below the control cabinet for use as measuring ambient temperature. The RTD should be mounted and guarded in a way that would discourage insect activity and limit possible physical damage. This RTD will be connected directly to the transformer monitor.

15. The control cabinet shall include swing out panels that house the technician interface equipment. Equipment includes the following: LTC controller, LTC adaptor panel, and LTC indicating lights on the left swing panel; Transformer Monitor and Cooling Equipment control switches on the right swing panel. All terminal blocks and other equipment are to be mounted on the back and sides of the enclosure or as approved by EWEB.

3.20 Accessories The following standard accessories shall be furnished with location in accordance with the latest ANSI Standards. Dial-type gauges shall be grouped together on one side of the transformer to the maximum extent possible. The dial-type gauges, valves, and no-load changer switch handle shall not protrude beyond the floor space determined by the radiating surfaces. All gauges over 96 inches from the ground shall have their faces tilted down at an angle of 30° from the vertical. Wells for thermometer bulbs and liquid level gauge floats shall be within the main tank so as not to require removal for untanking.

1. Manually operated no-load tap changer control handle shall be located on the side of the tank within easy reach from the ground and provided with means for padlocking in any position.

2. Magnetic liquid level gauge (with alarm contacts) set to close at the minimum safe operating level and with trip contacts set to close at a level 2 inches below the alarm contacts.

3. Dial-type oil thermometers with four (4) adjustable contacts each. (see section 3.16, #2 for temperature set points)

4. Pressure vacuum gauge with alarm contacts to indicate high and low transformer gas pressure.

5. Purge valve on the constant pressure system, together with a low N2 cylinder pressure alarm.





6. Globe-type combination drain and lower filter valve (2” screw end) with sampling device (3/8”). The drain valve and the oil-sampling valve shall be located so as to allow draining or sampling from the bottom surface of the tank.

7. Ball-type upper filter valve, 2” screw end. The oil filling connection shall be provided with deflection plates inside the main tank to prevent the force of incoming oil from impinging on the core and coil assembly and the associated leads.

8. All valves shall be made of brass or comparable non-corrosive material. Valves, except for the radiator port valves and the bottom drain valve, shall be of the ball-seat type with stainless steel balls, Teflon seals or EWEB approved equal. Valves with American Standard Pipe Threads or bolted and gasketed flanges shall be provided. The radiator port valves shall be a 3-inch minimum flange mounted butterfly-type valve.

9. Provide guards over any valve that may otherwise be used as a step.

10. Lifting eyes for the cover only.

11. Facilities for lifting core-and-coil assembly from tank without a spreader bar.

12. Lifting lugs for complete transformer.

13. Base to be designed for rolling, provision for pulling in both directions of centerlines of segments. The transformer base shall permit the transformer, complete and oil filled to be rolled over a concrete slab on three 2-inch steel rods without distortion of the base of the transformer.

14. Jacking provisions at four (4) corners of the base.

15. Four (4) ground pads with tapped holes for tank grounding (see EWEB Power Transformer Grounding specifications EC3-6.0501).

16. One (1) or more hand-holes or manholes in the cover.

17. Cover-mounted mechanical pressure relief device with automatic resealing-resetting operation and mechanical signal for indication of device operation.





Indicator design and mounting arrangement shall provide visibility from ground level near transformer. The pressure relief device shall be a QualiTrol model XPRD (Xtra Protection Redial Device).

18. Solid metal diagrammatic nameplate with embossed data in U.S. Customary units.

19. Removed.

20. An SEL-2414 Transformer Monitor (configuration 241421A3A9X3A851000) will be used to monitor the operation of the transformer and aggregate all I/O data from the transformer. The transformer monitor shall be mounted approximately 60” above the foundation to facilitate reading of the front panel display. As shown in EWEB standard drawing ED3-4.2100 (see reference drawings paragraph 3.27) this device will receive; signals from all resistance temperature detectors RTD on the transformer, all specified digital alarm indications, and specific CT inputs. The output contacts controlling Stage 1 and Stage 2 fans shall be included in the control circuit and the outputs shall not directly control the fan circuit but instead control an auxiliary relay/contactor to protect the output contacts of the transformer monitor. The device shall be powered by the 125VDC source. EWEB shall provide and install the fiber optic cable connection between the transformer monitor and fiber optic patch panel. EWEB shall also provide all programming for the transformer monitor.

21. The transformer shall be equipped with base plate(s) for fall protection system Uni-Hoist Part #NUH4000-2. The plate(s) shall be welded to the transformer tank per Uni-Hoist guidelines and include attachment points for worker D-ring during fall protection hoist erection.

3.21 Provision for Future Installation of a Hydran Two (2) 1-1/2” valves with 1-1/2” NPT female thread shall be provided on side tank wall approximately 18” and 24” up from the bottom of the transformer tank for the future installation of a Hydran.

The output end of the valve shall not be more than 1-1/2” from the oil flow.

A threaded cap shall be provided for the valve.





A clear space approximately 24” vertical by 12” horizontal shall be provided on the tank wall in the vicinity of the valve for the future installation of the electronic unit. Mounting brackets shall be provided in this space.

The mounting brackets shall consist of two (2) 6” lengths of 3” C-channels welded to the tank with the “C” on both channels facing the bottom of the tank with 15-3/8” between the top of the two (2) C-channels (or something similar).

3.22 Gaskets All manhole openings, bushing busses, or risers and any other areas where bolting is necessary will be provided with machined surfaces with a gasket groove to limit compression of the gasket material. All gasket material shall be reusable nitrile. Gaskets and gasket material containing asbestos shall not be used in any part of the transformer or its auxiliary equipment.

Each transformer shall be shipped with one complete set of gaskets in addition to those required to complete assembly.

3.23 Cleaning and Painting Transformer All surfaces of the transformer, tanks, covers, panels, etc., shall be thoroughly cleaned by de-greasing and abrasive blasting to remove grease, scale, rust, and corrosion. All surfaces shall then be given at least one (1) coat of rust-resistant primer.

The exterior surface of the transformer tank, covers, metal barrier, and the interior and exterior of panels, etc., shall be given two (2) coats of finish enamel. Color – ANSI No. 61 Gray, low-gloss, Alkyd Resin Enamel. The total paint thickness shall not be less than 3 mils at any point.

The interior of all control cabinets and the tank shall be painted white.

All transformer finishes shall adhere to the latest version of the EEI Finishing Guidelines for Padmount Equipment. All manufacturers shall furnish certified test results demonstrating that their coating system and application method meets the following minimum test requirements:

1. Salt Fog ResistancePer ASTM B117, 1500 hours.





2. Crosshatch AdhesionPer ASTM D3359, tape removal per Method B.

3. HumidityPer ASTM D2247, except at 45° C ± 1° C, there shall be no blisters.

4. ImpactPer ASTM D2794.

5. OUV Exposure Accelerated Weather TestExposure rate per ASTM G53; loss of gloss shall not exceed 50% as per ASTM D523.

6. Abrasion Test – Taber AbraserPer ASTM D4060, coating shall survive at least 3,000 abrasion cycles.

7. Oil ResistanceAs related to probable mineral oil contact. Immerse two (2) test panels in mineral oil for 72 hours, one at room temperature (20° C - 25° C) and one at 100° C - 105° C. There shall be no apparent changes such as color shift, blisters, loss of hardness, or streaking.

8. Moisture Condensation ResistancePer ASTM D1735. Prior to and upon completion of exposure test, specimen shall be tested for adhesion per ASTM D3359. There shall be 100% adhesion to bare metal and between paint layers

Items (9) through (12) may be provided at manufacturer’s option.

9. FlexibilityPer ASTM D1737, 180° bend.

10. Elcometer AdhesionMust provide psi value.

11. Dry Heat ResistancePer ASTM D2485.

12. Direct ImpactPer ASTMG 14.





3.24 Wind Loading & Seismic Wind Loading Strength: The transformer shall be designed to withstand wind loads as defined by local building code, or 95 miles/hour, whichever is greater, in its service configuration (i.e., with bushings, arresters, radiator/coolers, etc. installed). Documentation in the form of test data or calculations (either static or dynamic) confirming the transformer wind stand capabilities shall be provided with final drawings per paragraph 8.2.

Earthquake Strength: The completely assembled transformers shall meet the HIGH seismic qualification level as published in IEEE Standard 693 without damage. Dynamic testing or dynamic analysis results shall be provided with final drawings per paragraph 8.2.

3.25 Short Circuit Requirements The transformer is to be designed to meet the short circuit requirements given in the short circuit test code as per C57.12.00 and C57.12.90 latest revision.

Design test reports verifying compliance to short circuit requirements shall be provided with bid review drawings.

EWEB reserves the right to reject any design when, in the judgment of the Engineer, the manufacturer has not taken sufficient steps to meet the mechanical short-circuit requirements as listed in the paragraphs above.

Performance of short-circuit tests may be considered as a possible additional requirement. The manufacturer will include, as an alternative, a quotation for the performance of such tests, including the system conditions under which the test will be performed and the test procedures to be followed. The customer will advise the manufacturer at any time during the engineering and manufacturing cycle whether such tests will be required, but no later than two (2) weeks prior to shipment.

In addition to the above, each bidder shall submit with his proposal a complete listing of all full-sized transformers of his manufacturer, in ratings 501 through 50,000 kVA, which have been short-circuit tested. This list shall include all full-sized units tested, whether they were development tests or test of customer units. The list shall indicate if the test was a development test or a customer test. Complete ratings shall be given of each unit.

In case of units tested for or by the ultimate customer, indication shall be given on each unit as to whether the test was successful or unsuccessful and, if tested more than once,





each subsequent test shall be so listed and appropriate comments given as to design changes made, if any.

3.26 Transformer Loading The transformer and all associated parts shall be suitable for loading without exceeding loss-of-life as specified in ANSI C57.92. The manufacturer shall furnish necessary design constants and information as is related to the loading schedules, with the final drawings per paragraph 8.2.

3.27 Reference Drawing(s) The following reference drawing(s) are included as a part of this specification.

Drawing Number TitleED3-4.2100 SEL-2414 Transformer Monitoring Schematic & WiringED3-5.2001 Auto/Manual LTC Control SchematicEC3-6.0501 Power Transformer Grounding

4.0 ELECTRICAL TESTS The transformer shall be filled with in-service insulating fluid (FR3 in main tank and mineral oil in LTC tank) for all electrical tests.

Transformer will receive all routing and optional test in accordance with ANSI C57.12.90, C57.12.10, C57.15, and C57.90 including the following tests:

1. Cold resistance test on each winding on the rated voltage connection.

2. Polarity and phase relation test on the rated voltage connections.

3. No-load loss and exciting current shall be measured both at nominal rated voltage and at 105% and 110% of nominal rated voltage, both before and after impulse tests. Values of no-load loss and exciting current measured after impulse tests will be the values used in determining compliance with manufacturer’s performance guarantees; these values shall not exceed the values measured before impulse tests by more than 7.5%.

After the impulse test, load loss tests shall be performed on the unit at rated voltage, for DETC position 1 and DETC position 5 at base load (12 MVA or 20 MVA) at the neutral tap position, maximum boost position, and the position adjacent to the maximum boost position plus the maximum buck





position and the position adjacent to the maximum block buck position. Load loss tests shall also include tests at rated current (20 MVA or 33 MVA) and at rated voltage, for DETC position 1 and DETC position 5 at the neutral tap position, maximum boost position, and the position adjacent to the maximum boost position, plus the maximum buck position and the position adjacent to the maximum buck position.

4. H-winding to X-winding position sequence impedance shall be measured at nominal rated voltage.

5. Zero sequence impedances shall be measured if transformer is 3-phase core form; impedances shall be recorded in equivalent T-form, if applicable.

6. The following shall be calculated, based on measured losses and impedances; regulation at 1.0 and 0.8 power factor, and efficiency at 1.0 power factor and 0.25, 0.5, 0.75, and 1.25 times rated load.

7. Temperature test shall be performed at the maximum forced-cooled rating (if two or more duplicate units are ordered for manufacturer at the same time, EWEB may elect to require temperature test on only one of such units); dissolved gas analysis shall be performed on transformer oil samples taken immediately before and immediately after temperature testing. The manufacturer shall establish acceptable limits for the incremental increase of the dissolved gases listed below. These limits are to be furnished as part of the Approval Drawing package and are subject to acceptance by EWEB.

The manufacturer shall furnish the calculated hot-spot winding temperature rise corresponding to the highest measured value of average winding temperature rise at both the self-cooled rating and the maximum forced-cooled rating

8. All dissolved gases tests (DGA) shall include the following gases at a minimum:

Hydrogen (H2) Methane (CH4) Ethane (C2H6) Ethylene (C2H4) Acetylene (C2H2) Carbon Monoxide (CO)





Carbon Dioxide (CO2) Oxygen (O2)

Nitrogen (N2)

The initial DGA sample shall be taken after the unit is oil-filled and prior to any electrical dielectric tests are performed. In addition to the DGA tests performed immediately before and after the temperature rise test, all units will have a final DGA test performed at the factory just prior to shipment.

9. Capacitance and insulation power factor between windings and between each winding and ground shall be measured. A power-factor test shall be performed on all windings and bushings at 10 kV. No winding shall exceed a 0.5% power factor. For each high voltage terminal, an excitation current test shall be performed at 10 kV on each de-energized tap.

10. Control wiring and contacts shall be tested with 60-hertz potential of 1,000V applied for 60 seconds.

11. One-hour, 3-phase induced potential and corona test shall be performed. The first test voltage to be applied shall be 182 kV rms phase-to-phase and an enhancement voltage level of 208 kV with the transformer set on the maximum DETC tap. The test voltage shall be applied for a period of one (1) hour. Tests shall be accompanied by continuous monitoring of partial discharge level; level shall be recorded at 5-minute intervals. Measured partial discharge level shall not exceed 100 microvolts or shall not exceed 250 pico Coulombs (including background).

12. NEMA audible sound level tests will be performed in accordance with the latest revision of C57.12.91 without forced-cooling equipment in operation, and with two stages of forced-cooling in operation.

13. Applied potential tests.

14. Induced potential tests.

15. Impulse test on line terminals, for the chopped wave test the time to chop shall be between 2 and 6 microseconds. All impulse tests shall be performed with the DETC set on the maximum tap and the LTC in either the 15 raise or lower position.





16. Temperature test(s) shall precede all dielectric tests, including impulse and switching surge tests. In accordance with ANSI C57.12.90, impulse and switching surge tests shall precede the low-frequency dielectric tests.

17. Manufacturer’s test report shall include diagrams showing winding connections (including windings or terminals not being tested) and voltages applied for impulse and switching surge tests, if specified, and for 7200-cycle induced tests.

18. Insulation resistance shall be measured at 10 kV DC. Test report shall include actual readings; readings corrected to 20° C, a polarization index for each test connection (the ratio of the 10-minute reading to the 1-minute reading); and the make, model, and serial number of the measuring instrument. For measurements between windings, the tank and windings not being tested shall be “guarded.” For measurements between windings and ground, test report shall show the condition of windings not being tested (whether “guarded” or grounded).

19. The manufacturer shall perform a Sweep Frequency Analysis (SFRA) test. The manufacturer shall submit with the final documentation a complete diagram of the test performed and the test report.

20. Test for unintentional core grounds shall be performed after loading for shipment.

21. After the transformer is filled with oil at the manufacturer’s plant in preparation for performance of transformer tests, a sample of oil shall be taken from the transformer and analyzed to determine the level of polychlorinated biphenyl contamination, if any. Prior to shipment, the assembled transformer will be liquid-filled and pressure-tested for a minimum of 24 hours at 10 psig pressure for detecting the presence of leaks. There shall be no drop in pressure for the successful completion of this test.

22. The manufacturer shall notify the customer of the dates of the above-referenced tests shall be performed not less than four (4) weeks prior to performing any of the tests.





23. EWEB reserves the right to witness the specified tests and will notify the manufacturer two (2) weeks prior to the date of testing if EWEB will witness the testing of the unit(s).

24. Certified test reports shall be provided within three (3) weeks of shipment and shall include the results of all the tests indicated above.

5.0 BID EVALUATION

5.1 Losses Cost of Losses = (A x No-Load Losses) + (B x Load Losses)

A = Cost of No-Load Losses in dollars/KWB = Cost of Load Losses in dollars/KW

Should the combined losses of the transformer when tested exceed the guaranteed combined losses, an amount as determined by the equation above will be withheld from the bid price as damages. No credit will be given for actual losses that are less than the guaranteed values.

5.2 Sound Level Sound Costs = (C – NEMA Sound Level at Transformer Base Rating + D – NEMA Sound Level at Transformer Maximum Rating) * $5000.00/db

C = Guaranteed Sound Level at base MVAD = Guaranteed Sound Level at maximum MVA

Acceptable Sound Levels per NEMA TR 1-2013:20MVA transformer at 12 MVA = 71db20MVA transformer at 20MVA = 74db33MVA transformer at 20 MVA = 73db33MVA transformer at 33 MVA = 76db

Should the sound levels of the transformer at either load value when tested exceed the guaranteed sound level, an amount as determined above, will be withheld from the bid price as damages. No credit will be given for actual sound levels that are below the guaranteed values.

5.3 Technical Alternative





Should the manufacturer choose to propose an alternative or take exception to any item or portion of these specifications, the manufacturer shall clearly state the alternative(s) or exception(s) and technical reasoning supporting the alternative(s) or exception(s). Statements like “in accordance with manufacturer’s standard procedures” are unacceptable and may make the Bidder’s proposal subject to disqualification.

5.4 Factory Inspection Bidder is encouraged to document their manufacturing process and demonstrate how their process aligns with the requirements of this specification. Bidders should highlight their QA during manufacturing, effectiveness and experience of their testing department, and how the manufacturer has incorporated technology into the manufacturing process.

EWEB reserves the right, prior to award of the contract, to perform a factory inspection of the plant(s) where the transformers will be manufactured, assembled, tested, packed, and shipped.

Bidder, along with the manufacturer’s representative (if not the same) must be prepared to host EWEB factory inspection within 14 days of request by EWEB. EWEB must be allowed to observe all areas of operation (reference above) to validate Bidder’s ability to meet the requirements of the contract.

Should a “Notice of Intent” be issued and as a result of the factory inspection EWEB is not confident in Bidder’s ability to meet the requirements of the contract, EWEB reserves the right to rescind its notice and reject Bidder’s bid.

6.0 WARRANTY Bidder warrants to EWEB that any goods/equipment furnished will operate and function in the manner represented by Bidder and will achieve the performance stated in the material specification when operating within the design conditions described.

Bidder warrants the goods/equipment furnished is free from defects in material and workmanship, and agrees to repair or replace any unit that is unsuitable for operating or fails in operation during normal and proper use, including all parts and labor at no cost to EWEB. EWEB reserves the right to complete repairs internally upon mutual agreement or when manufacturer or assignee does not complete repairs within 72 hours of notification. Work completed by EWEB will be covered under Warranty when documented and performed by a qualified technician. Internal repairs will be billed to manufacturer at current EWEB labor rates plus 20%, plus materials, payment terms are net 30.





EWEB requires a factory representative to be present during transformer assembly at the EWEB site, and shall inspect and approve final assembly before EWEB field tests are performed.

EWEB requires a minimum warranty period of five (5) years after the date of final acceptance. In addition, any defect in the design or manufacture discovered by the manufacturer and/or the purchaser in the warranty period shall be corrected to EWEB’s satisfaction at no cost to the purchaser.

The equipment manufacturer must have service and repair facilities capable of complete overhaul. The manufacturer must have five (5) years experience or more in the design, manufacturing, and testing of power transformers of this size and voltage class.

7.0 PACKAGING All bushings and accessories susceptible to damage shall be adequately protected to insure against damage during transit. The transformer will be filled with dry nitrogen at a minimum pressure of three (3) psig. A conspicuous tag will be placed in nitrogen system compartment specifying the actual nitrogen pressure and the ambient temperature at the time of filling.

Major transformer components shall be removed for shipment including but not limited to; high voltage bushings, radiators and lightning arrester supports. Metal components i.e. radiators and lightning arrestor supports shall be metal stamped on the component and the transformer to identify the location and orientation of the components.

The manufacturer will be responsible for checking the shipping dimensions, clearances and weight for shipment to the specified destination together with acquiring any and all required permits.

The manufacturer will furnish and install not less than two (2) 3-way impact recorders before shipment of the transformer. The recorders will be mounted on the transformer tank wall near the top on opposite tank walls. Prior to the transformer leaving the factory, the impact recorders shall be started and verified that they are working properly. The impact recorders are to remain on the transformer until both the manufacturer’s representative and EWEB’s representative are present to witness their removal together with the review of the data. Tracking information for impactor recorders (if applicable) shall be sent to EWEB prior to the start of transit.





Acceptable limits of impact and ranges of impact requiring additional inspection or testing shall be furnished to EWEB not less than 30 calendar days prior to delivery.

8.0 BIDDER INFORMATION

8.1 Installation Engineer The services of a competent engineer specializing in installation work may be required to inspect the complete installation and be responsible for the proper installation and operation of the transformer, and for any tests that may be necessary. Bidders shall state the total costs of travel expense, services and expenses of the engineer while working at the installation site and all other costs EWEB will be expected to pay, in the bid form. Personnel whose primary duties are sales will not be acceptable.

8.2 Drawing and Instruction Books All prints, instruction books, etc., shall be sent to the Buyer’s attention, Eugene Water & Electric Board, Purchasing Office, 4200 Roosevelt Boulevard, Eugene, Oregon 97402.

Drawing approval before construction is required. The manufacturer shall furnish drawings for approval in AutoCAD and PDF format through a secure FTP site or CD/DVD. These drawings shall include a general outline drawing, nameplate, wiring schematics and connection diagrams and list of equipment and accessories by style number. The outline drawings shall include anchoring details of the tank base together with dimensions, weights, center of gravity, insulating fluid volume and weights and foundation loadings. The drawings shall also include foundation reactions produced by equipment operation and by wind and seismic forces. The approval drawings must be received at EWEB no later than eight (8) weeks after receipt of order by manufacturer.

The manufacturer shall supply at least thirty (30) days before shipment of the transformer, four (4) sets of final prints of all drawings and four (4) sets of instruction books. One (1) complete instruction book and set of drawings shall accompany transformers. One CD/DVD shall be included additionally with all the below documentation included in PDF or Microsoft Office Suite format. The final documents shall include, but not be limited to, the following:

1. Assembled transformer outline drawing (including bushing locations and connection points, centerline location and sizes of all control cabinet conduit plates; structural details of transformer base; center of gravity of installed unit and of unit prepared for shipment; and minimum dimensions and weight of unit prepared for shipment).





2. Nameplate drawing (including identification of type of winding connection and conductor material used in each winding).

3. Bushings outline drawings.

4. Surge arrester outline drawings.

5. Terminal fitting drawings.

6. Schematic and wiring diagrams showing number, size, and power requirements of fans and pumps; fan and pump control; alarm and relay connections; and current transformer connections.

7. Complete point-to-point wiring drawings shall be supplied for all electrical circuits installed on the transformer by the manufacturer.

8. Instruction manual covering receiving, handling, installation, operation and maintenance of transformer and all auxiliary equipment.

A. Complete instructions and data for ordering of all parts and accessories.

B. Complete instructions covering installation, assembly, operation, maintenance and adjustment of the transformer and all associated equipment. Cuts or drawings or descriptive information shall be provided showing all points where adjustment may be made.

C. Complete instructions for maintenance of bushings, including any special instruction required for disassembly and assembly of the bushing or its parts.

D. Complete parts list, including a breakdown of all assemblies, including name or included drawings.

E. Spare parts list as recommended by the manufacturer, including the information listed in the preceding paragraph.

F. A list of the special tools, if applicable, being provided by the manufacturer.

9. Certified test reports (for each transformer) including all tests performed on the transformer, weather requested by EWEB or not.





8.3 Schematic and Wiring Diagram Specifications

The manufacturer shall provide diagrams showing the complete control cabinet and terminal box wiring including: (1) EWEB connection points, (2) the number, size, and power requirements of fans and pumps, (3) the fan and pump control, (4) the alarm and relay connections, (5) the current transformer connections, and (6) the load tap changing equipment control.

Wiring diagrams shall be physically representative of the arrangement of equipment and of the format shown below in Figure 1. Wiring tables/lists are not acceptable.

An electronic copy of all final drawings shall be furnished at or before delivery of equipment. These files shall be compatible with EWEB’s latest AutoCAD standard, which EWEB will send to the successful Bidder.

In addition to the two dimensional drawings EWEB requests an electronic three dimensional model (3D) of transformer be provided. This model should also be provided in a format that is compatible with the latest version of AutoCAD. The model is not held to the same drafting standards requirements as the working drawings mentioned above. If 3D is not available, the drawings should contain sufficient information that a 3D model can be created from the drawings. For example there should be views from all sides including the top and bottom. The drawings should be fully dimensioned.

8.4 Current Transformer Information





The manufacturer shall provide the following: (1) current transformer resistance per winding turn, (2) resistance of each lead, (3) curves showing ratio correction and secondary excitation for relaying, and (4) ratio and phase angle correction for metering.

8.5 Correspondence

Correspondence regarding this document, and technical questions regarding this material specification, or notice of any other technical matters which arise during the proposal process shall be directed to the Purchasing Office, Eugene Water & Electric Board.

The successful bidder will be provided contact information for EWEB Engineering and the bidder will correspond directly with Engineering during the equipment design, manufacture, testing and delivery phases.

9.0 TAP CHANGER OPERATIONS

The manufacturer shall state the number of operations for which the load tap changer contacts are guaranteed.





SPECIFIC INFORMATION REQUIRED WITH QUOTATION(Submit Separate Sheets for Each Bid Item)

Bidder shall submit the following complete descriptive information and performance specifications on this form with his proposal.

1. Losses

All transformer losses listed below will be for transformer in the 117.875kV tap position. All quoted below shall include any auxiliary losses.

a. No Load Losses at neutral __________watts

b. No Load Losses at 15R __________watts

c. No Load Losses at 16R __________watts

d. No Load Losses at 15L __________watts

e. No Load Losses at 16L __________watts

f. Load Losses at 12 or 20 MVA and neutral __________watts

g. Load Losses at 12 or 20 MVA and 15R __________watts

h. Load Losses at 12 or 20 MVA and 16R __________watts

i. Load Losses at 12 or 20 MVA and 15L __________watts

j. Load Losses at 12 or 20 MVA and 16L __________watts

k. Load Losses at 20 or 33 MVA and neutral __________watts

l. Load Losses at 20 or 33 MVA and 15R __________watts

m. Load Losses at 20 or 33 MVA and 16R __________watts

n. Load Losses at 20 or 33 MVA and 15L __________watts

o. Load Losses at 20 or 33 MVA and 16L __________watts

The No-Load loss values to be used in the equation in Section 5 of this specification shall be determined by averaging the five (5) no-load loss values stated above.

The load loss values to be used in the equation in Section 5 of this specification shall be determined by averaging the ten (10) load loss values stated above.



August 14, 2015 REV. ES3-9.130 12 PAGE 37 OF 42


2. Excitation Current

All the excitation currents listed below will be for the transformer DETC in the 117.875kV tap and the LTC in the neutral position.

a. Excitation Current at rated voltage: H1__________mA

H2__________mA

H3__________mA

b. Excitation current at 105% of rated voltage: H1__________mA

H2__________mA

H3__________mA

c. Excitation current at 110% of rated voltage: H1__________mA

H2__________mA

H3__________mA

3. Sound Levels

All sound levels quoted and the sound level tests shall be for the transformer DETC in the 117.875kV tap and the LTC in 15 raise position.

a. Calculated sound level at base MVA __________db

b. Calculated sound level at maximum MVA __________db

c. Guaranteed sound level at base MVA __________db

d. Guaranteed sound level at maximum MVA __________db

Sound levels shall be based on the guaranteed sound level at the two (2) MVA levels listed above. This credit will be reflected in the total evaluation as determined in Section 5 of this specification.





4. Impedances

a. H to X at 12 or 20 MVA (circle transformer size) __________%

5. Outline Dimensions

a. Overall height __________inches

b. Height of tank __________inches

c. Bushing removal __________inches

d. Phase spacing high voltage __________inches

e. Phase spacing low voltage __________inches

f. Length of transformer __________inches

g. Width of transformer __________inches

6. Weights

a. Fully assembled transformer __________pounds

b. Tank with cover & coils (shipping weight) __________pounds

7. Oil

a. Capacity __________gallons

b. Weight __________pounds

8. Bushings

a. High Voltage Type __________________

b. Manufacturer __________________

c. Catalog Number __________________

d. Current Rating __________A

e. Bushing-stud size-diameter __________inchesThreads __________per inch

f. Low Voltage Type __________________





g. Manufacturer __________________

h. Catalog Number __________________

i. Current Rating __________A

j. Bushing-stud size-diameter __________inchesThreads __________per inch

9. Oil Preservation System

__________________

10. Type of Cooling

a. Cooling each stage -Stage 1 __________-Stage 2 __________

b. Power Required -Stage 1 __________-Stage 2 __________

11. Arresters

a. High Voltage Type __________________

b. Manufacturer __________________

c. Catalog Number __________________

d. Maximum spark over voltages

Front of wave __________kV

1.5 x 50 wave __________kV

Switching surge __________kV

IR Drop at 10,000 amp __________kV

IR Drop at 20,000 amp __________kV

Maximum continuous operating voltage __________kV

e. Low Voltage Type __________________

f. Manufacturer __________________

g. Catalog Number __________________





h. Maximum spark over voltages

Front of wave __________kV

1.2 x 50 wave __________kV

Switching surge __________kV

IR Drop at 10,000 __________kV

IR Drop at 20,000 __________kV

Maximum continuous operating voltage __________kV

12. Load Tap Changer (LTC)

a. LTC Manufacturer __________________

b. LTC Catalog Number __________________

c. Rated switching current of LTC __________A

d. Rated step voltage of LTC __________V

e. Voltage ration of booster transformer, is used __________

f. Number of operations of LTC at full load before maintenance __________

13. No-Load Tap Changer (NLTC)

a. NLTC Manufacturer __________________

b. NLTC Catalog Number __________________

c. Current rating of NLTC __________A

d. Short-circuit current rating of NLTC __________kA

14. Typical outline drawing(s).

Information provided on proposal page number(s). __________________

15. List of recommended spare parts


16. List of short circuit tests to show compliance with ANSI C57.12.90.






17. Average number of years the manufacturer’s engineers have been electrical transformer engineers.

18. Average number of years the manufacturer’s mechanical engineers have been mechanical engineers.

19. Average number of years the manufacturer’s winders have been power transformer winders.




Power Transformer 115kV/12.47kV Web viewThe tank cover shall be domed and external features shall be...

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