UPS 1000S/ UPS 1200S Uninterruptible Power Supplys Caterpillar

Illustration 1	g01342924
MOV Surge Protector Location, Rear Panel (1) MOV Surge Protector (2) MOV Circuit Breaker (3) Wire Terminal

The MOV Surge Protector is located on the back panel of the Input/Output Cabinet, beneath the input cable landings. Refer to Illustration 1.

The MOV Surge Protector is connected to the 3-phase input power and monitors the incoming voltage for spikes. When a spike is detected, resistance in the MOV is overcome. Then, the extra voltage is diverted to ground.

The MOV is protected by a 480V, 30A circuit breaker.

There are three LEDs on the front of the MOV. There is one LED for each phase. These LEDs indicate proper operation of the MOV.

Removal

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Illustration 2	g01274453
MOV Surge Protector

1. Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Input/Output Cabinet)" in order to de-energize the system and gain access to internal components.

2. Disconnect the wires that lead from the back of the MOV Surge Protector to the MOV circuit breaker. Disconnect the wires at the circuit breaker. There are three black wires. The wires are labeled according to their locations. Verify the labels on the cables for subsequent re-installation.

3. Remove the four bolts that secure the surge protector bracket to the rear of the cabinet, using a 178 mm (7/16 inch) socket.

4. Loosen the large nut that attaches the MOV to the bracket.

5. Remove the MOV from the bracket.

Installation

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Illustration 3	g01274472
MOV Surge Protector Fasteners, Top View

1. Route the wires that come from the back of the MOV through the bracket.

2. Route the large nut onto the wires.

3. Rotate the nut onto the threaded portion of the MOV.

4. Attach the MOV bracket to the back of the cabinet in the position indicated in 1. Four bolts attach the bracket, one at each corner.

5. Tighten the bolts to 11.2985 N·m (100 lb in). Use a 178 mm (7/16 inch) socket

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Illustration 4	g01274458
MOV Surge Protector Connections, Top View (1) MOV Surge Protector (2) MOV Circuit Breaker (K10)

6. Connect the wires coming from the back of the MOV to the top connectors on the MOV circuit breaker. Refer to Illustration 1 and the following steps.

7. Use a small flat head screwdriver in order to loosen each cable connector screw. Access to the screws are through the front of the breaker.

8. Insert the wire into the top of the breaker and between the connector plates.

9. Tighten the cable connector screws to hold the wires in place.