SOW_RSB-DC_(rev2_6__2016).pdf

STATEMENT OF WORK FOR

DAY/NIGHT RANGE LIGHT SWITCH BOX - DC VERSION (RSB-DC)

Rev. 06/16

1.0 General. The Day/Night Range Light Switch Box - DC Version, hereafter referred to as RSB-DC, will be used at solar powered 12-Volt DC day/night range lights of up to 240 watts. The RSB-DC uses a very simple switching technique to toggle between daytime and nighttime operation depending solely on ambient light conditions. A Type L photoresistor mounted on the side of the switch box continuously monitors nearby light levels. When the ambient light level rises above a preset threshold, a relay-driver circuit activates a power relay which turns on the daytime light and turns off the nighttime light.

Since simplicity was a key factor in the electrical control circuit design, there is no provision for external monitoring or control, nor is it intended. The RSB-DC will be installed and serviced by personnel with limited electrical/electronic experience and/or knowledge.

1.1 Deliverables.

1.1.1 The following item shall be provided:

a. RSB-DC as described in the Requirements paragraph (2.0) below.

2.0 Requirements. The RSB-DC shall be assembled in accordance with Figure 1 (Parts Placement Diagram) and Figure 2 (Electrical Wiring Diagram). Contractor shall use the exact parts in the requirements’ subparagraphs below, where specified. However, the contractor may propose to the Contracting Officer in writing the substitution of parts equivalent or better in design, performance, quality, and/or construction, accompanied by official documentation which supports such equivalency. No substitutions shall be made without prior written approval from the Contracting Officer.

2.1 Enclosure. The enclosure shall be a Hoffman NEMA 4X, fiberglass, hinged cover with quick release latches, Hoffman catalog number A-12106CHQRFG (12"x 10"x 6" overall dimension). It shall be equipped with a 10.75"x 8.88" internal corrosion resistant aluminum alloy mounting panel type 5052H32 with an irridite finish applied in accordance with MIL-C-5541 Class 1A. The mounting panel shall be installed inside the enclosure with four (4) stainless steel machine screws at the corners. The mounting panel shall have a thickness of 0.10 + 5% inch. All hardware penetrating the enclosure shall be installed using gaskets properly fitted to maintain weatherproof integrity.

2.2 Relay. The relay, RY1, shall be a Magnecraft SPDT power relay model number Magnecraft W199X-2 (12V DC coil). It shall be mounted such that its contactor arm is oriented vertically in reference to the enclosure with the hinge positioned below the contacts.

2.3 Photoresistor. The Coast Guard will provide standard Type L photoresistors upon award of contract. One photoresistor will be issued for each deliverable RSB-DC. The photoresistor shall be installed in the Myers Hub described in subparagraph 2.5 below.

2.4 Relay Driver Circuit Card Assembly (Relay Driver CCA). The Relay Driver CCA is a constituent part of the RSB-DC. One Relay Driver CCA is required for each deliverable RSB-DC. Contractor shall fabricate the Relay Driver CCA according to the accompanying Statement of Work for Relay Driver Circuit Card Assembly. Contractor shall install and connect the Relay Driver CCA inside each deliverable RSB-DC according to the Electrical Wiring Diagram (Figure 2).

2.5 Myers Hub. One each Myers Hub number ST-2 (¾"-14 NPT) to accommodate the Type L photoresistor shall be positioned on the right side of the enclosure, centered and mounted as close to the top edge as possible. The photoresistor shall be installed in the hub using Teflon tape to ensure a weather-tight seal.

2.6 Circuit Breaker. The circuit breaker, CB1, shall be a Heinemann AM1R-B8-AC07D- A-30-5 30-Amp DC magnetic type circuit breaker. CB1 shall be installed to the front of the mounting panel using a custom made irridited aluminum "Z" mounting bracket.

2.7 Terminal Blocks. Four each required. Two shall be Buchanan section compression-type Nos. D814/830 combination (sized for #1/0 AWG wire) for TB1(+) and TB2(-) (TB1 shall be color coded black and TB2 shall be white as shown in Figure 1). The other two terminal blocks shall be Buchanan section compression-type Nos. D614/D614/630 combination (sized for #10 AWG wire) for TB3(Night) and TB4(Day) (these shall be color coded as shown in Figure 1). These terminal blocks may have limited availability. If locating and procuring these items proves difficult, Contractor may propose an alternate solution to the Contracting Officer for review.

2.8 Inserts (Press Nuts). RY1, CB1, Relay Driver CCA, and terminal blocks TB1 thru TB4 shall be installed to the mounting panel using flush-mount threaded inserts (press nuts) installed from the rear of the panel. This eliminates the need to access the rear of the panel should relay, circuit breaker, circuit card assembly, or terminal block replacement become necessary.

2.9 Stuffing Tubes. Four each required. Dorn nylon stuffing tube size 4T (M19622/1-

005) w/packing assembly 4E1 (M19622/19-0006) for the two #1/0 POWER IN wires and the two #10/2 load (Day & Night) SO cables.

2.10 Internal Wiring. Color coded #8-, #12-, and #18-AWG stranded wire shall be used as indicated in the Electrical Wiring Diagram (Figure 2).

2.11 Wire Terminals. Connections to CB1 and RY1 shall be made using non-insulated ring tongue terminals sized for either #8- or #18-AWG wire as indicated in Figure 2. After crimping, all wires shall be soldered to the terminals.

2.12 Ground Stud. One stainless steel bolt (1" long, stud size ¼" UNC threaded), two stainless steel ¼" UNC threaded nuts, two stainless steel flat washers, and one stainless steel split lock washer shall be assembled to form the ground stud. The ground stud bolt shall be installed from rear of panel and cinched down tight with one nut and split lock washer from the front. Remaining hardware shall be installed onto the stud.

2.13 Silk-screening. Silk-screening shall be applied to the mounting panel including labeling and naming of the terminal strips, terminals, the Relay Driver CCA, the relay, the circuit breaker, the ground stud, serial number, and the equipment identifier as shown in Figure 1.

2.14 Labels. A permanent vinyl self-adhesive stick-on Electrical Wiring Diagram (camera-ready copy of the diagram will be supplied upon award of contract) shall be attached to the inside of the enclosure cover. On the outside of the enclosure cover, stick-on vinyl labels with the following information shall be permanently attached: "Range Switch Box - DC" and "Property of U.S. Coast Guard" in black letters against a white background.

2.15 Workmanship. The RSB-DC’s delivered under this statement of work shall be constructed in accordance with MIL-STD-454, Requirement 9.

2.16 Desiccant Bag. To reduce damaging effects of possible high humidity exposure during long-term storage, one silica gel desiccant bag of at least 720 cu. in. effective volume, similar to McMaster-Carr catalog item number 2189K17, shall be packaged inside each RSB-DC enclosure just prior to shipping.

3.0 Quality Assurance. All RSB-DC boxes shall successfully pass the following electrical test:

3.1 Electrical Test.

a. Switch CB1 to the "OFF" position.

b. Apply 12VDC to TB1(+) and TB2(-).

c. Switch CB1 to the "ON" position.

d. Expose the photoresistor to a bright light source.

e. Ensure the relay is energized, and, using a DVM, confirm that 12VDC is present at

TB4 (DAY) and not present at TB3 (NIGHT).

f. Cover the photoresistor with a piece of black electrical tape.

g. Ensure the relay has de-energized and that 12VDC is now present at TB3 (NIGHT) but no longer present at TB4 (DAY). End of test.

4.0 Packing and Packaging. All RSB-DC boxes shall be individually packaged in a container suitable for reshipment. Packaging shall be adequate to prevent damage and loosening of parts during handling and transit.

4.1 Marking. Each shipping container shall contain the following information:

Requirement Example

Stock Number: CG5930-01-GL3-5876 Contents: Range Switch Box - DC (RSB-DC) Quantity: 1 ea.

Contract Number: DTCG23-XX-X-XXXXXX Comany Name & Address: ABC Comany, Anytown USA

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