SECTION 16321

DISTRIBUTION TRANSFORMERS

PART 1 GENERAL

SECTION INCLUDES

Pole mounted distribution transformers.

Liquid filled pad mounted distribution transformer.

Dry type pad mounted distribution transformer.

RELATED SECTIONS

Section 03300 - Cast-In-Place Concrete: Pads for transformer support.

Section 16370 - Overhead Power Distribution: Poles and cutouts.

REFERENCES

ANSI C37.47 - Specifications for Distribution Fuse Disconnecting Switches, Fuse Supports, and Current-Limiting Fuses.

ANSI/IEEE C57.12.01 - General Requirements for Dry-Type Distribution and Power Transformers.

ANSI C57.12.20 - Requirements for Overhead Type Distribution Transformers, 500 kVA and Smaller: High- Voltage, 67000 Volts and Below; Low-Voltage, 15000 Volts and Below.

ANSI C57.12.22 - Requirements for Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers with High-Voltage Bushings; High Voltage, 34500 GrdY/19920 Volts and Below; 2500 kVA and Smaller.

ANSI/IEEE C57.12.90 - Test Code for Liquid-Immersed Distribution Power, and Regulating Transformers.

ANSI/IEEE C57.12.91 - Test Code for Dry-Type Distribution and Power Transformers.

ANSI/IEEE C57.13 - Requirements for Instrument Transformers.

ANSI/IEEE 386 - Separable Insulated Connector Systems for Power Distribution Systems Above 600 V.

ASTM D877 - Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes.

NEMA AB1 - Molded Case Circuit Breakers.

NEMA 260 - Safety Labels for Padmounted Switchgear and Transformers Sited in Public Areas.

SUBMITTALS

Submit shop drawings under the provisions of Section [01300.] [01340.]

Submit shop drawings indicating outline dimensions, connection and support points, weight, specified ratings and materials.

Submit product data under the provisions of Section [01300.] [01340.]

Submit product data indicating standard model design tests and options.

Submit manufacturer's installation instructions under provisions of Section [01300.] [01340.]

OPERATION AND MAINTENANCE DATA

Submit operation and maintenance data under provisions of Section [01700.] [01730.]

Include procedures for [sampling and maintaining fluid,] cleaning unit, and replacing components.

QUALITY ASSURANCE

Manufacturer: Company specializing in distribution transformers with [three] [_____] years [documented] experience.

DELIVERY, STORAGE, AND HANDLING

Store and protect products under provisions of Section [01600.] [01620.]

Protect dry type transformers from moisture by using appropriate heaters as instructed by the manufacturer.

PART 2 PRODUCTS

MANUFACTURERS - POLE MOUNTED TRANSFORMERS

[______________________________] Model [__________.]

[______________________________] Model [__________.]

[______________________________] Model [__________.]

Substitutions: Under provisions of Section [01600.] [01630.]

POLE MOUNTED DISTRIBUTION TRANSFORMERS

Transformers: ANSI C57.12.20; [single] [three] phase, oil-filled, self-cooled transformer with primary bushings, [lightning arrestor, primary fuse, secondary circuit breaker,] and secondary terminations.

Capacity: [_____] kVA.

Primary Voltage: [____] kV, [[(delta] [_____] connected;] provide standard primary taps, with externally-operated tap changer.

Secondary Voltage: [_____] volts, [[wye] [_____] connected.]

Impedance: [2.0] [___] percent.

Basic Impulse Level: [60] [75] [95] [125] kV.

Temperature Rise: 65 degrees C above 30 degrees C ambient.

Accessories: ANSI C57.12.20 standard accessories [and] [magnetic liquid level gage,] [dial type thermometer,] [and] [____________________.]

MANUFACTURERS - PAD MOUNTED TRANSFORMERS

[______________________________] Model [__________.]

[______________________________] Model [__________.]

[______________________________] Model [__________.]

Substitutions: Under provisions of Section [01600.] [01630.]

PAD MOUNTED TRANSFORMERS

Liquid-filled Transformers: ANSI C57.12.22; three phase, pad mounted, self-cooled transformer unit.

****** [OR] ******

Dry-type Transformers: ANSI/IEEE C57.12.01; [single] [three] phase, pad-mounted, self-cooled transformer unit.

Capacity: [_____] kVA.

Primary Voltage: [_____] kV, [[delta] [_____] connected;] provide standard primary taps, with externally-operated tap changer.

Secondary Voltage: [_____] volts, [[wye] [_____] connected.]

Impedance: [5.75] [_____] percent.

Basic Impulse Level: [30] [60] [75] [95] [125] kV.

Cooling and Temperature Rise; ANSI C57.12.22; Class OA. [55] [65] degrees C, self-cooled.

Liquid: [Oil.] [Silicon.] [High fire point liquid.]

Accessories: ANSI C57.12.22 standard accessories [and] [magnetic liquid level gage,] [dial type thermometer,] [and] [____________________.]

Cooling and Temperature Rise: ANSI/IEEE C57.12.01; Class AA. 220 degree C insulation class with 150 degree C rise over 40 degree C ambient.

Primary Terminations: Bushing wells to ANSI/IEEE 386; provide [three for radial feed.] [six for [loop] [primary selective] feed.] Include bushings for insulated loadbreak connectors.

****** [OR] ******

Primary Terminations: Porcelain insulator with clamp-type connector.

Primary Switching: Fused air switch, gang operated.

****** [OR] ******

Primary Switching: Internal oil-immersed gang-operated load break switch. [Provide two, for [primary selective switching.] [loop feed.]]

Primary Overcurrent Protection: [Internally-mounted, oil-immersed, expulsion fuses.] [Bayonet-type, oil-immersed, expulsion fuses.] [Current-limiting fuses to ANSI C37.47.]

Secondary Terminations: Spade lugs.

Secondary Switching and Overcurrent Protection: Molded case circuit breaker to NEMA AB1.

Other Accessories: [Primary lightning arrestors] [and] [secondary current transformers to ANSI/IEEE C57.13.]

PART 3 EXECUTION

EXAMINATION

Verify that [pads] [poles] are ready to receive work.

Verify field measurements are as [shown on Drawings.] [instructed by manufacturer.]

Verify that required utilities are available, in proper location and ready for use.

Beginning of installation means installer accepts conditions.

INSTALLATION

Install in accordance with manufacturer's instructions.

Install safety labels to NEMA 260.

FIELD QUALITY CONTROL

Field testing will be performed under provisions of Section [01400.] [01410.]

Test dielectric liquid to ASTM D877, using 25,000 volts minimum breakdown voltage, after installation and before energizing from system.

Test transformer to ANSI/IEEE C57.12.90.

Test transformer to ANSI/IEEE C57.12.91.

ADJUSTING

Adjust work under provisions of Section [01650.] [01660.]

Adjust primary taps so that secondary voltage is within [2] [___] percent of rated voltage.

END OF SECTION