262200 Low Voltage Transformers seismic.pdf

UPGRADE EMERGENCY POWER IN BUILDING 138 VAMC, MAR ION, IN

PROJECT: 610-16-104 01-01-17

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SECTION 26 22 00

LOW-VOLTAGE TRANSFORMERS

PART 1 – GENERAL

1.1 DESCRIPTION

A. This section specifies the furnishing, installat ion, connection, and testing of low-voltage dry-type general-purpose tra nsformers, indicated as transformers in this section.

1.2 RELATED WORK

A. Section 03 30 00, CAST-IN-PLACE CONCRETE: Req uirements for concrete equipment pads.

B. Section 13 05 41, SEISMIC RESTRAINT REQUIREMEN TS FOR NON-STRUCTURAL

COMPONENTS: Requirements for seismic restraint of n onstructural components.

C. Section 26 05 11, REQUIREMENTS FOR ELECTRICAL IN STALLATIONS:

Requirements that apply to all sections of Division 26.

D. Section 26 05 19, LOW-VOLTAGE ELECTRICAL POWER C ONDUCTORS AND CABLES:

Low-voltage conductors.

E. Section 26 05 26, GROUNDING AND BONDING FOR ELEC TRICAL SYSTEMS:

Requirements for personnel safety and to provide a low impedance path for possible ground fault currents.

F. Section 26 05 33, RACEWAY AND BOXES FOR ELECTRIC AL SYSTEMS: Conduit.

1.3 QUALITY ASSURANCE

A. Quality Assurance shall be in accordance with Pa ragraph, QUALIFICATIONS

(PRODUCTS AND SERVICES) in Section 26 05 11, REQUIR EMENTS FOR

ELECTRICAL INSTALLATIONS.

1.4 SUBMITTALS

A. Submit in accordance with Paragraph, SUBMITTALS in Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS, and the following requirements:

1. Shop Drawings:

a. Submit sufficient information to demonstrate com pliance with drawings and specifications.

b. Include electrical ratings, dimensions, mounting details, materials, required clearances, terminations, weigh t, temperature rise, wiring and connection diagrams, plan, front, side, and rear elevations, accessories, and device nameplate data.

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c. Certification from the manufacturer that represe ntative transformers have been seismically tested to Intern ational

Building Code requirements. Certification shall be based upon simulated seismic forces on a shake table or by ana lytical methods, but not by experience data or other method s.

2. Manuals:

a. Submit, simultaneously with the shop drawings, c ompanion copies of complete maintenance and operating manuals inclu ding technical data sheets and wiring diagrams.

1) Schematic signal and control diagrams, with all terminals identified, matching terminal identification in the transformers.

2) Include information for testing, repair, trouble shooting, assembly, disassembly, and factory recommended/requ ired periodic maintenance procedures and frequency.

b. If changes have been made to the maintenance and operating manuals originally submitted, submit updated mainte nance and operating manuals two weeks prior to the final insp ection.

3. Certifications: Two weeks prior to final inspect ion, submit the following.

a. Certification by the manufacturer that the trans formers conform to the requirements of the drawings and specificati ons.

b. Certification by the Contractor that the transfo rmers have been properly installed, adjusted, and tested.

1.5 APPLICABLE PUBLICATIONS

A. Publications listed below (including amendments, addenda, revisions, supplements, and errata) form a part of this specif ication to the extent referenced. Publications are referenced in t he text by designation only.

B. International Code Council (ICC):

IBC-15..................International Building Code

C. National Fire Protection Association (NFPA):

70-20...................National Electrical Code (N EC)

D. National Electrical Manufacturers Association (N EMA):

TR 1-13.................Transformers, Step Voltage Regulators and

Reactors

ST 20-14................Dry Type Transformers for G eneral Applications

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E. Underwriters Laboratories, Inc. (UL):

UL 506-17...............Standard for Specialty Tran sformers

UL 1561-11..............Dry-Type General Purpose an d Power Transformers

F. United States Department of Energy:

10 CFR Part 431.........Energy Efficiency Program f or Certain

Commercial and Industrial Equipment

PART 2 - PRODUCTS

2.1 TRANSFORMERS

A. Unless otherwise specified, transformers shall b e in accordance with

NEMA, NFPA, UL and as shown on the drawings.

B. Transformers shall have the following features:

1. Self-cooled by natural convection, isolating win dings, indoor dry-type. Autotransformers will not be accepted, except as specifically allowed for buck-boost applications.

2. Rating and winding connections shall be as shown on the drawings.

3. Ratings shown on the drawings are for continuous du ty without the use of cooling fans.

4. Copper windings.

5. Insulation systems:

a. Transformers 30 kVA and larger: UL rated 220 °C (428 °F) system with an average maximum rise by resistance of 150 ° C (302 °F) in a maximum ambient of 40 °C (104 °F).

b. Transformers below 30 kVA: Same as for 30 kVA an d larger or UL rated 185 °C (365 °F) system with an average maximu m rise by resistance of 115 °C (239 °F) in a maximum ambient of 40 °C (104

°F).

6. Core and coil assemblies:

a. Rigidly braced to withstand the stresses caused by short-circuit currents and rough handling during shipment.

b. Cores shall be grain-oriented, non-aging, and si licon steel.

c. Coils shall be continuous windings without splic es except for taps.

d. Coil loss and core loss shall be minimized for e fficient operation.

e. Primary and secondary tap connections shall be b razed or pressure type.

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f. Coil windings shall have end filters or tie-down s for maximum strength.

7. Average audible sound levels shall comply with N EMA.

8. If not shown on drawings, nominal impedance shal l be as permitted by

NEMA.

9. Single phase transformers rated 15 kVA through 2 5 kVA shall have two

5% full capacity taps below normal rated primary vo ltage. All transformers rated 30 kVA and larger shall have two 2.5% full capacity taps above, and four 2.5% full capacity ta ps below normal rated primary voltage.

10. Core assemblies shall be grounded to their encl osures with adequate flexible ground straps.

11. Enclosures:

a. Comprised of not less than code gauge steel.

b. Outdoor enclosures shall be NEMA 3R.

c. Temperature rise at hottest spot shall conform t o NEMA Standards, and shall not bake and peel off the enclosure paint after the transformer has been placed in service.

d. Ventilation openings shall prevent accidental ac cess to live components.

e. The enclosure at the factory shall be thoroughly cleaned and painted with manufacturer's prime coat and standard finish.

12. Standard NEMA features and accessories, includi ng ground pad, lifting provisions, and nameplate with the wiring d iagram and sound level indicated.

13. Dimensions and configurations shall conform to the spaces designated for their installations.

14. Transformers shall meet the energy conservation standards for transformers per the United States Department of En ergy’s 10 CFR

Part 431.

PART 3 - EXECUTION

3.1 INSTALLATION

A. Installation of transformers shall be in accorda nce with the NEC, as recommended by the equipment manufacturer and as sh own on the drawings.

B. Anchor transformers with rustproof bolts, nuts, and washers, in accordance with manufacturer’s instructions, and as shown on drawings.

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C. In seismic areas, transformers shall be adequa tely anchored and braced per details on structural contract drawings to with stand the seismic forces at the location where installed.

D. Install transformers with manufacturer's recomme nded clearance from wall and adjacent equipment for air circulation. Mi nimum clearance shall be 6 inches.

E. Install transformers on vibration pads designed to suppress transformer noise and vibrations.

3.2 ACCEPTANCE CHECKS AND TESTS

A. Perform tests in accordance with the manufacture r's recommendations.

In addition, include the following:

1. Visual Inspection and Tests:

a. Compare equipment nameplate data with specificat ions and approved shop drawings.

b. Inspect physical and mechanical condition.

c. Inspect all field-installed bolted electrical co nnections, using the calibrated torque-wrench method to verify tight ness of accessible bolted electrical connections.

d. Perform specific inspections and mechanical test s as recommended by manufacturer.

e. Verify correct equipment grounding.

f. Verify proper secondary phase-to-phase and phase -to-neutral voltage after energization and prior to connection to loads.

3.3 FOLLOW-UP VERIFICATION

A. Upon completion of acceptance checks, settings, and tests, the contractor shall demonstrate that the transformers are in good operating condition, and properly performing the in tended function.

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