SPECIAL SPECIFICATION

SECTION 16461-S

[SMALL POWER PADMOUNT TRANSFORMERS]{.underline}

[PART 1 - General 2](#__RefHeading___Toc172694041)

[1.01 DESCRIPTION 2](#__RefHeading___Toc172694042)

[1.02 QUALITY ASSURANCE 2](#__RefHeading___Toc172694043)

[1.03 SUBMITTALS 2](#__RefHeading___Toc172694044)

[PART 2 - products 4](#__RefHeading___Toc172694045)

[2.01 KVA RATINGS 4](#__RefHeading___Toc172694046)

[2.02 VOLTAGE RATINGS AND TAP RATINGS 4](#__RefHeading___Toc172694047)

[2.03 CORE DESIGN 4](#__RefHeading___Toc172694048)

[2.04 HIGH VOLTAGE TAPS 4](#__RefHeading___Toc172694049)

[2.05 TRANSFORMER IMPEDANCES 4](#__RefHeading___Toc172694050)

[2.06 SHORT-CIRCUIT CAPABILITY 5](#__RefHeading___Toc172694051)

[2.07 OVERCURRENT PROTECTION 5](#__RefHeading___Toc172694052)

[2.08 CONSTRUCTION 5](#__RefHeading___Toc172694053)

[2.09 MANUFACTURERS 7](#__RefHeading___Toc172694054)

[2.010 LOW VOLTAGE BUSHINGS AND TERMINALS
7](#__RefHeading___Toc172694055)

[2.011 HIGH-VOLTAGE BUSHINGS AND TERMINALS
7](#__RefHeading___Toc172694056)

[2.012 ACCESSORIES 8](#__RefHeading___Toc172694057)

[2.013 JACKING, ROLLING, LIFTING AND MOUNTING FACILITIES
8](#__RefHeading___Toc172694058)

[2.014 TERMINAL MARKINGS 8](#__RefHeading___Toc172694059)

[2.015 INSTRUCTION NAMEPLATE 9](#__RefHeading___Toc172694060)

[2.016 OIL PRESERVATION 9](#__RefHeading___Toc172694061)

[2.017 TANKS 9](#__RefHeading___Toc172694062)

[PART 3 - Execution 9](#__RefHeading___Toc172694063)

[3.01 INSTALLATION 9](#__RefHeading___Toc172694064)

[3.02 IDENTIFICATION TAGS 10](#__RefHeading___Toc172694065)

[PART 4 - EVALUATION 10](#__RefHeading___Toc172694066)

[4.01 LOSS EVALUATION 10](#loss-evaluation)

SPECIAL SPECIFICATION

SECTION 16461-S

SMALL POWER PADMOUNT TRANSFORMERS

[]{#__RefHeading___Toc172694041 .anchor}[General]{.underline}

1.  []{#__RefHeading___Toc172694042 .anchor}DESCRIPTION

    A.  This specification is written for three-phase, 60 hertz, 65oC
        temperature rise, liquid filled, self-cooled, pad mounted,
        live-front, compartmentalized distribution transformers, rated
        1,500 KVA and below, radial feed.

    B.  Pad mounted transformers shall be provided and installed in
        accordance with the details and ratings on the working drawings,
        and in accordance with this specification.

2.  []{#__RefHeading___Toc172694043 .anchor}QUALITY ASSURANCE

    A.  All characteristics, definitions, terminology, and voltage
        designations, except as otherwise specified herein, shall be in
        accordance with applicable provisions of the latest edition of
        ANSI C57.12.22, or its successors, and applicable ANSI C57
        series specifications including C57.12.00-1987 (or the latest
        editions).

    B.  Manufacturer will state the edition and date of ANSI C57.12.22
        on submittals.

3.  []{#__RefHeading___Toc172694044 .anchor}SUBMITTALS

    A.  The following shall be submitted in accordance with Sandia
        Specification 01300.

        1.  Outline drawings including overall height, overall width,
            overall depth, base dimensions, clearances required for
            opening doors, arrangement of bushings, and other
            appurtenances, and compartment dimensions.

        2.  Weights of tank, oil, transformer total, and shipping
            weight.

        3.  Volume of oil, gallons.

        4.  Material Safety Data Sheet for transformer oil.

        5.  Test and Performance Data.

            a.  The manufacturer shall perform all routine tests as
                defined in ANSI C57.12.00-1987 (or the latest edition).

            b.  The manufacturer shall provide Sandia with the following
                certified data by transformer serial number for each
                transformer shipped.

                1.  Excitation loss, watts.

                2.  Impedance, % Z.

                3.  Total loss, watts.

                4.  No load loss, watts.

                5.  Full load loss, watts.

                6.  Exciting current at 100% and 110% of rated voltage.

                7.  Average excitation loss in accordance with ANSI
                    C57.12.00-1987 (or the latest edition), Section 9,
                    paragraph 9.3, and Table 16, line 3.

                8.  Average total loss in accordance with ANSI
                    C57.12.00-1987 (or the latest edition), Section 9,
                    paragraph 9.3, and Table 16, line 3.

                9.  Percent impedance volts, of the low voltage winding
                    with respect to the high voltage winding at rated
                    self cooled KVA.

                10. Steady state transformer top oil temperature rise
                    above ambient, degree Celsius.

                11. Transformer oil time constant, time for top oil to
                    obtain 63% of steady state rise above ambient.

                12. Certified statement of compliance with short circuit
                    capability requirements of Paragraph 3.06.

                13. Certification of tamper resistant design with
                    complete test data.

        6.  Manufacturer shall certify that all transformers supplied
            under this specification contain less than 1 ppm PCB.

        7.  All required information and laboratory test performance
            data per Section 3.1.2 of \"EEI Finishing Guidelines for
            Padmounted Equipment,\" Draft 6.

        8.  No individual transformer shall be shipped with losses that
            exceed quoted losses by more than the tolerances in ANSI
            C57.12.00-1987 (or the latest edition), Table 16, line 2,
            without written approval of SNL, SCR.

            []{#__RefHeading___Toc172694045
            .anchor}[products]{.underline}

4.  []{#__RefHeading___Toc172694046 .anchor}KVA RATINGS

    A.  Kilovolt-ampere ratings shall be 500, 750, 1000, and 1500.

5.  []{#__RefHeading___Toc172694047 .anchor}VOLTAGE RATINGS AND TAP
    RATINGS

    A.  Voltage ratings, minimum BIL rating, and tap ratings shall be in
        accordance with Table I, below.

TABLE I

+-----------+-----------+-----------+-----------+-----------+-----------+
| High      | BIL       | Low       | BIL       | KVA       | High      |
| Voltage   | Rating    | Voltage   | Rating    | Rating    | Voltage   |
| Ratings   | (KV)      | Rating    | (KV)      |           | Taps      |
| (Volts)   |           | (Volts)   |           |           | Required  |
| Delta     | Delta     |           |           |           |           |
|           |           | WYE       |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 12470     | 95        | 4160      | 60        | 500-1500  | 2-2 ½ %   |
|           |           |           |           |           | Abv & Bel |
+-----------+-----------+-----------+-----------+-----------+-----------+

6.  []{#__RefHeading___Toc172694048 .anchor}CORE DESIGN

    A.  Transformers shall be of five-legged core design and connected
        delta-wye.

7.  []{#__RefHeading___Toc172694049 .anchor}HIGH VOLTAGE TAPS

    A.  High voltage taps shall be provided in accordance with Table I.
        Taps shall be suitable for de-energized operation only. The tap
        changer switch shall be ganged and shall be externally operable.
        The operating handle shall be located either in the high voltage
        compartment above the primary bushings or in the secondary
        compartment above the low voltage bushings. The tap changer
        shall be set on the 100% tap at the factory and shall be secured
        to prevent inadvertent change from this position.

8.  []{#__RefHeading___Toc172694050 .anchor}TRANSFORMER IMPEDANCES

    A.  Minimum impedances shall be in accordance with Table II, below:

TABLE II

Secondary Voltage

\*Minimum AC Impedance %

  ---------------------------------- ------------------------------------
  KVA                                2400 Delta

  500                                5.75

  750                                5.75

  1000                               5.75

  1500                               5.75
  ---------------------------------- ------------------------------------

\*ANSI Standard Tolerance

9.  []{#__RefHeading___Toc172694051 .anchor}SHORT-CIRCUIT CAPABILITY

    A.  Mechanical short-circuit capability shall be demonstrated by
        design compliance with ANSI C57.12.90-1987 (or the latest
        edition).

    B.  Thermal short-circuit capability shall be demonstrated by design
        compliance with ANSI C57-12.00-1987 (or the latest edition).

10. []{#__RefHeading___Toc172694052 .anchor}OVERCURRENT PROTECTION

    A.  Overcurrent protection devices shall not be supplied in radial
        feed transformers.

11. []{#__RefHeading___Toc172694053 .anchor}CONSTRUCTION

    A.  Description

        1.  Transformers shall be designed to protect people against
            accidental contact of energized parts, discourage
            unauthorized access to or climbing upon the unit by the
            public and protect against weather.

        2.  The padmounted transformer shall consist of the transformer
            tank, high voltage cable terminating compartment, and the
            low voltage cable terminating compartment. The transformer
            tank and compartment shall be assembled as a raintight
            compartment, outdoor, and tamper resistant integral unit
            suitable for mounting on a flat surface.

        3.  There shall be no exposed screws, bolts, or other fastening
            or hinging devices (other than the pentahead bolt specified
            in 2.08 D.5) which are externally removable. There shall be
            no opening through which foreign objects such as sticks or
            wires might be inserted to contact energized parts. Suitable
            means for padlocking the compartment door(s) shall be
            provided. Normal entry shall be possible only with the use
            of proper access tools.

        4.  The high- and low-voltage compartments shall be located side
            by side on one side of the transformer tank. When facing the
            compartment, the low voltage compartment shall be on the
            right.

        5.  Construction of the unit shall be such that it can be
            lifted, skidded, and slid into place on the mounting pad
            without disturbing the entrance cables.

        6.  All external surfaces shall be constructed of steel, 13 USS
            gauge or thicker.

        7.  The transformer and compartment hoods shall be crowned to
            insure water run off.

    B.  Bottom Protection

        1.  The transformer tank base shall be raised above the pad to
            protect the bottom finish during installation and to
            minimize corrosion due to moisture accumulation. The base
            shall be cross braced to permit rolling in two directs.

        2.  All external surfaces of ferrous material used in the
            construction of the assembly shall have undercoating over
            the regular finish, applied to the bottoms of the components
            and extending up the side to a point one inch above the
            bottom of their bases.

    C.  Protective Coating

        1.  All coated surfaces both exterior and interior shall be
            painted using a system which conforms to the requirements of
            \"EEI Proposed Finishing Guidelines for Padmounted
            Equipment,\" Draft 6. The finish coat shall be light gray
            (ANSI Color No. 70).

    D.  High and Low-Voltage Compartments

        1.  Terminal compartments shall be full height, air filled
            compartments with separate hinged doors. The compartments
            shall be completely isolated from each other by a steel
            barrier without opening or discontinuity of any kind.

        2.  The edges of the access doors and hoods shall be formed to
            provide a close fitting mating surface, with internal
            insertion-prevention lip that will be shaped to resist entry
            or prying by screwdrivers, wrecking bars, tire irons,
            single-socket lug wrenches or other readily accessible
            tools.

        3.  Hinges and hinge pins shall be passivated AISI Type 304
            stainless steel or equivalent corrosion-resistant metal.

        4.  There shall be a threaded fastening device for the high
            voltage door, accessible only through the low voltage
            compartment. Screen door latches with wing nuts, gravity
            hooks, etc., are acceptable. The low voltage compartment
            door shall have a minimum of three point latching and the
            handle shall have provisions for pad locking. The padlocking
            provision shall be so designed and located as to resist
            prying or breaking off by screwdrivers, wrecking bars, tire
            irons, single-socket lug wrenches or other readily
            accessible tools and to inhibit removal of the padlock with
            a bolt cutting device or hacksaw.

        5.  In addition to the regular locking provision above, the
            access doors shall be secured by a captive, recessed
            pentahead bolt as depicted in Figure 11, ANSI C57-12.26-1987
            (or the latest edition). Bolts and associated hardware must
            be rust and corrosion resistant and the design shall
            minimize the possibility of misalignment and
            cross-threading. The design must be such that wire entry
            through the bolt hole into the compartment(s) is prohibited
            when the bolt is removed. The non-rotating cup shall be
            permanently attached.

            a.  The captive pentahead bolt shall be coordinated with the
                latch and padlock to prevent unlatching and insertion of
                the padlock into the hasp when and until the bolt is
                completely threaded, respectively.

            b.  The captive pentahead shall also function as an
                interlock device to pin the latch closed.

        6.  Both compartment doors shall be equipped with stops for
            holding each door in a 90o open position. The stops shall be
            captive to prevent loss of the device.

        7.  Doors on the high- and low-voltage compartments shall be of
            sufficient size to provide adequate working space when open.

        8.  The bottom edge of the transformer shall provide for flush
            mounting on a flat rigid surface to prevent wire entry into
            the high- or low-voltage compartments.

12. []{#__RefHeading___Toc172694054 .anchor}MANUFACTURERS

    A.  Padmount transformers manufactured by ABB Company, General
        Electric, Cooper Industries or Howard Industries are acceptable
        to Sandia.

13. []{#__RefHeading___Toc172694055 .anchor}LOW VOLTAGE BUSHINGS AND
    TERMINALS

    A.  Bushings arrangement for live front, radial feed transformers
        shall comply with the latest revision of ANSI C57.12.22 1987.

    B.  Low-voltage bushings are to be made of wet-process porcelain and
        clamped externally to the wall of the transformer. Reusable
        nitrite rubber gaskets shall seal the bushing to the tank wall
        in the terminals to the porcelain.

    C.  Low-voltage terminals shall be 2-hole blade spades with NEMA
        hole spacing to provide six holes.

    D.  Low-voltage cable terminals shall be oriented for vertical
        take-off of secondary cables entering the compartment from
        below.

14. []{#__RefHeading___Toc172694056 .anchor}HIGH-VOLTAGE BUSHINGS AND
    TERMINALS

    A.  Bushings arrangement for live front, radial feed transformers
        shall comply with the latest revision of ANSI C57.12.22.19.87.

    B.  High-voltage bushings are to be made of wet-process porcelain
        and clamped externally to the wall of the transformer. Reusable
        nitrite rubber gaskets shall seal the bushing to the tank wall
        in the terminals to the porcelain.

    C.  Transformer sizes of 500-1500 KVA, shall have 2-hole blade
        terminals with 9/16-inch diameter holes.

    D.  High-voltage cable terminals shall be oriented for vertical
        take-off of primary cables entering the compartment from below
        in accordance with Figure 4, ANSI C57.12.22-1989.

    E.  Transformer design shall allow field replacement of high voltage
        bushing wells and low voltage bushings by means of common hand
        tools and oil handling equipment, without totally untanking the
        transformer.

15. []{#__RefHeading___Toc172694057 .anchor}ACCESSORIES

    A.  The following accessories are required on all transformers and
        located in the low voltage compartment in such a manner as to
        not interfere with low voltage terminals:

        1.  Pressure relief device.

        2.  Upper filter valve or plug.

        3.  One inch combination drain, lower filter valve, and sampling
            device. Combination drain plug and sampling device may be
            substituted.

        4.  Liquid level gauge.

        5.  Top oil thermometer.

16. []{#__RefHeading___Toc172694058 .anchor}JACKING, ROLLING, LIFTING
    AND MOUNTING FACILITIES

    A.  Suitable jack bosses or equivalent jacking facilities shall be
        provided on the tank. Vertical clearance for jack shall be 1 1/2
        inches minimum, 3 1/2 inches maximum.

    B.  Transformer base shall be arranged for rolling in two
        directions: parallel to and at right angles to the center line
        of the high-voltage bushings.

    C.  Lifting lugs shall be adequately strengthened, sized, and
        arranged on the tank to provide a suitable lift for the
        completely assembled unit.

    D.  A 3/4 inch minimum and a 1 1/2 inch maximum integral flange
        shall be provided at the base of the high-voltage and
        low-voltage compartments, to provide means of anchoring the unit
        to the pad.

17. []{#__RefHeading___Toc172694059 .anchor}TERMINAL MARKINGS

    A.  External terminals on radial feed transformers shall be marked
        H1, H2, H3, and X1, X2, and X3 by stenciled white lettering on
        the tank.

    B.  A winding diagram with high- and low-voltage connections shall
        be shown on the instruction nameplate.

18. []{#__RefHeading___Toc172694060 .anchor}INSTRUCTION NAMEPLATE

    A.  Instruction nameplate shall be located on the inside of the
        low-voltage compartment door.

    B.  Instruction nameplate shall contain the information specified in
        paragraph 5.12 of ANSI C57.12.00-1987 (or latest edition),
        nameplate B.

    C.  Nameplate shall indicate that the transformer oil contained less
        than 1 ppm PCB at time of manufacture.

19. []{#__RefHeading___Toc172694061 .anchor}OIL PRESERVATION

    A.  Transformers shall be of sealed tank construction, so designed
        that the interior is sealed from the atmosphere and the gas plus
        oil volume remains constant. The transformer shall remain
        effectively sealed for all temperatures to plus 105oC top oil.

20. []{#__RefHeading___Toc172694062 .anchor}TANKS

    A.  The tank shall be of sufficient strength to withstand a pressure
        of 7 psi gage, without permanent distortion.

        1.  Welded main cover construction shall be provided. Access to
            internal connection for test purposes shall be provided by
            means of a handhole, accessible only from the padlocked
            compartments.

        2.  Tank grounding provision shall consist of:

            a.  Two unpainted copper-faced steel or stainless steel
                pads. 2 inches x 3 1/2 inches each with two holes spaced
                on 1-3/4 inch centers and tapped for 1/2 inch - 13 NC
                thread. The minimum thickness of the copper facing shall
                be 0.015 inch. Minimum threaded depth of holes shall be
                1/2 inch.

        3.  These ground pads shall be welded on the transformer base or
            on the tank wall near the base, one in the high-voltage
            compartment and one in the low-voltage compartment.

            []{#__RefHeading___Toc172694063
            .anchor}[Execution]{.underline}

21. []{#__RefHeading___Toc172694064 .anchor}INSTALLATION

    A.  Transformer shall be installed on a concrete pad as shown on
        contract drawings. Handling of the transformer shall be in
        accordance with manufacturer\'s instructions.

    B.  Touch up scratched or marred surface to match original finish.

    C.  Check for damage and tighten connections prior to energizing
        transformer.

    D.  Energization of primary circuits and transformer shall be in
        accordance with Sandia specification 16475, \"Primary System
        Safety Requirements\" and contract drawings.

    E.  Upon energization of the transformer, the phase rotation shall
        be verified and secondary voltages measured, line-to-line and
        line-ground, on all phases.

22. []{#__RefHeading___Toc172694065 .anchor}IDENTIFICATION TAGS

    A.  All transformers shall have 3-1/4\" identification tags
        identifying transformer number per contract documents. Tags
        shall be black letters on yellow background, 3-1/4\" high,
        reflective pressure sensitive, Almetek brand.

        []{#__RefHeading___Toc172694066 .anchor}EVALUATION

## 4.01 ***LOSS EVALUATION***

A.  Transformers bid under this specification will be evaluated for no
    load losses and load losses using the present worth method. Each
    type of loss is associated with a demand charge and an energy
    charge. The present value of carrying charges associated with each
    of the charges are multiplied by the appropriate loss figure
    supplied by the manufacturer for each unit then added to the each
    unit bid transformer price to obtain the total evaluated cost (TEC)
    per unit:

    a.  TEC = T\$ + PVDC x NLL + PVEC x LL; where:

    b.  TEC = Total Evaluated Cost

    c.  T\$ = Unit bid transformer price, \$

    d.  PVDC = Present worth value of demand charges per kilowatt of no
        load losses, \$/KW.

    e.  PVEC = Present worth value of energy charges per kilowatt of
        load losses, \$/KW.

    f.  NLL = Transformer no load losses, KW.

    g.  LL = Transformer load losses, KW.

> Current Values:
>
> PVDC = \$8134.00
>
> PVEC = \$3326.00

B.  In the event actual losses exceed the losses guaranteed, SNL shall
    have the right to either reject the equipment or to accept the
    equipment for a reduced price. The amount due SNL shall be
    calculated as follows:

    a.  Price Reduction = (NLLA - NLLQ) x PVDC +(LLA - LLQ) x PVEC;
        where:

    b.  NLLA = Actual transformer no load losses, KW.

    c.  NLLQ = Quoted transformer no load losses, KW.

    d.  LLA = Actual transformer load losses, KW.

    e.  LLQ = Quoted transformer load losses, KW.

\- END OF SECTION -