Portable Pier-Class Power Distribution Center (PDC) with Integrated Transformation

Salient Characteristics

1.0 Description: NPTU has a need for a portable pier electrical transformation unit. The unit will consist of two

NEMA 4X rated panels and step-down transformer mounted on a single frame. The electrical panels and supporting frame structure shall be designed to be used outdoors in a brackish water environment. The unit will take 460-

480Vac through a set of cam-locking connectors to a 400A main circuit breaker and distribution panel. Internal distribution circuit breakers will supply power to connectors as dictated below. One of the distribution circuit breakers will provide a feed to a 75 kVA 480V/ (208/120) VAC step-down transformer. The output of the step-down transformer will serve as input power to the secondary distribution panel, equipped with a 200 A circuit breaker.

The secondary distribution panel will have circuit breakers that supply power to connectors as dictated below.

For pre-award evaluation purposes, offerors shall provide sufficient technical information to demonstrate compliance with these salient characteristics. At a minimum, offerors shall provide a technical description of the proposed unit, a compliance matrix, a conceptual one-line diagram or equivalent electrical layout, supporting cut sheets or component literature for major components, and any exceptions or assumptions. Detailed preconstruction/fabrication submittals are not required with the quotation unless otherwise stated in the solicitation.

2.0 Delivery Information:

NPTU Charleston

1260 Snow Pointe Rd.

Goose Creek, SC 29485

3.0 Electrical Specifications

3.1. Primary Input Power & Method

• Voltage: 480 VAC

• Phase: 3

• Amperage: 400 A

• Wire: 3 – 1 ground

• Method: One set of E1022 compatible (Duraline or equivalent) male single pole cam-type receptacles

(Black, White, Red, and Green)

3.2. Primary Enclosure Style

• NEMA 4X

• Circuit breaker access shall be available dead front and located behind a hinged (or otherwise approved) cover

3.3. Primary Main Circuit Breaker

• 400 A

3.4. Primary Circuit Breakers/Receptacles

QTY Voltage Amperage Receptacle Type Model

3 sets 480 250 (1)

(4) E1016 single pole cam-type

(Brown, Orange, Yellow, Green) Duraline, or equivalent

3 480 30 NEMA L16-30R

1 480 15 NEMA L16-30R

1 480 30

MIL-R-2726/16

NSN: 5935-00-892-8971

MIL-SPEC

1 480 50 NEMA L16-30R

1 480 60 460R7W HUBBELL, or equivalent

1 480 (2) N/A – Power Source for Transformer Input

(1) Provide an adjustable trip circuit breaker with capability of changing OCP setpoints

(2) Size circuit breaker for transformer and cable overcurrent protection IAW applicable electrical codes

3.5. Transformer

• Power: 75 kVA

• 480 V Delta Primary, 120/208V WYE Secondary

• Dry-Type, Air (non-forced) Cooled

• Primary adjustment taps with (2) 2.5% increments above and below nominal voltage (minimum) o Tapped to -2.5%

• Enclosure: NEMA 3R (Minimum)

3.6. Secondary Enclosure Style

• NEMA 4X

• Circuit breaker access shall be available dead front and located behind a hinged (or otherwise approved) cover

3.7. Secondary Main Circuit Breaker

• 200 A

3.8. Secondary Circuit Breakers/Receptacles

QTY Voltage Amperage Receptacle Type Model

1 208 60 560R9W HUBBELL, or equivalent

2 sets 208 150(1) (5) E1016 single pole cam-type

(Black, Red, Blue, White, Green)

Duraline – Female, or equivalent

2 208 20 NEMA L6-20R

1 208 30 NEMA L6-30R

1 208 50 NEMA L6-50R

1 208 20 NEMA L15-20R

1 208 30 NEMA L15-30R

1 208 50 NEMA L15-50R

1 208 40 PS460R12W

Legrand Pass &

Seymour, or equivalent

6 120 20 NEMA 5-20R

3 120 20 NEMA L5-20R

1. Provide an adjustable trip circuit breaker with capability of changing OCP setpoints

4.0 Special Instructions

4.1. General

All commercially available equipment sourced by the supplier to support fabrication of the unit shall be UL listed

(i.e. receptacles, circuit breakers, terminal blocks, cable). Equipment custom designed/fabricated by the supplier

(i.e. framing, custom built electrical enclosures) does not require a UL listing. If it is necessary to use non-UL listed equipment (not meeting the “custom designed/fabricated” statement above) to meet the requirements as stated herein, NPTU approval is required.

4.2. Electrical Design

1. Design and installation shall conform to National Electrical Code (NFPA 70) standards, including GFI protection.

2. All service feeds shall be at or near the side bottom or direct bottom of each panel.

3. Electrical feeds to and from the transformer shall be environmentally protected.

4. Multi-wire branch circuits are not allowed.

5. 480 VAC panel shall be rated for 35 KAIC minimum. The 120/208 VAC Panel must be rated for a minimum of

10 KAIC and shall be sized in accordance impedance characteristics of the transformer selected.

6. All penetrations shall be weather tight.

7. All receptacle covers shall have NEMA 3R (minimum) covers.

8. All cam-type receptacles shall have NEMA 3R (minimum) flip lids.

9. Provide external ground lug/ground cam-lock connection for all Duraline type cam-lock receptacles.

10. Provide a standard (i.e. lug, cam-lock, or equivalent) means of grounding the frame, enclosures, and transformer secondary neutral connection.

11. If housed in the same enclosure, provide physical barriers between the 480V and 120/208V distribution systems.

12. Provide for personnel access to internal components for servicing and maintenance.

13. Provide external labels to indicate receptacle voltage, amperage, and supplying circuit breaker.

4.3. Frame Design

1. All distribution components shall be on the same frame.

2. Frame shall be equipped with forklift pockets and lifting eyes.

3. Frame shall be fabricated using 304 stainless steel or higher grade as approved by NPTU.

4. All carbon steel components connected to the frame shall be electrochemically isolated from the frame by painting, coating, non-metal shims, or other methods as approved by NPTU.

5. All fasteners used externally to the panels shall be 304 stainless or higher grade as approved by NPTU.

6. Limits for weight and dimensions is no greater than 1800 lbs., 60”Wx36”Dx72”H.

5.0. Testing

Testing shall conform to the ANSI/NETA ATS. At a minimum, the following tests shall be performed:

• Insulation resistance of all conductors

• Transformer turns-ratio testing (at the nominal, +2.5%, -2.5% only)

• Transformer insulation resistance

6.0. Deliverables

6.1 Pre-Award Offeror Submission Requirements

Offerors shall provide sufficient technical information for evaluation of compliance with the salient characteristics.

At a minimum, offerors shall provide:

1. A technical description of the proposed unit

2. A compliance matrix addressing these salient characteristics

3. A conceptual one-line diagram or equivalent electrical layout

4. Supporting cut sheets or component literature for major components

5. A list of exceptions, assumptions, or deviations

6. Delivery lead time information

6.2 Post-Award Preconstruction Submittals

The successful contractor shall provide the following to Site Engineering at NPTU Charleston for review and approval prior to fabrication/construction:

1. Preconstruction drawings (including frame, preliminary list of materials, and electrical details (i.e. one-line diagrams) shall be provided to Site Engineering at NPTU Charleston for approval prior to construction.

6.3 Final Deliverables

The successful contractor shall provide:

2. A final set of as-built drawings, including transformer tap details (if not located on the transformer enclosure), shall be provided be provided to Site Engineering at NPTU Charleston.

3. Results of testing as described above.