UPS 250, UPS 300, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supply Caterpillar

Illustration 1	g03404458
(1) "J2 24 VDC Power In" (2) "J1 APC I/O" (3) "J5 JTAG I/O" (4) "J4 Lo Fuse Sense" (5) "J3 Hi Fuse Sense" (6) "J7 DC-" (7) "J8 DC Com" (8) "J6 DC+"

Illustration 2	g00812333
(9) DC Interface Board

Removal Procedure

1. Place the system in bypass mode by turning the keyswitch to the Bypass position.

2. Isolate the system from the load by closing the bypass circuit breakers.

3. Open the circuit breaker for the output of the system.

4. Open the AC circuit breaker for the input of the system.

5. Allow the capacitor banks to bleed down for approximately 5 minutes.

   Note: When the flywheel is spinning, the following components are energized: the bus, the armature leads and the fuses. Accomplish the procedure as quickly as possible. During the procedure, the rotor is spinning on the bottom bearing.

6. Label all the input wires and all of the output wires.

7. Disconnect the "Lo Fuse" connector from terminal "J4" (4) .

8. Disconnect the "Hi Fuse" connector from terminal "J3" (5) .

9. Disconnect the "DC+" connector from terminal "J6" (8) .

10. Disconnect the "DC-" connector from terminal "J7" (6) .

11. Disconnect the "DC Com" connector from terminal "J8" (7) .

12. Disconnect the "APC I/O" connector from terminal "J1" (2) .

13. Disconnect the "Power" connector from terminal "J2" (1) .

14. Remove the board from the four plastic mounting spacers.

Installation Procedure

1. Install the new board.

2. Connect the "Power" connector to terminal "J2" (1) .

3. Connect the "APC I/O" connector to terminal "J1" (2) .

4. Connect the "DC Com" connector to terminal "J8" (7) .

5. Connect the "DC-" connector to terminal "J7" (6) .

6. Connect the "DC+" connector to terminal "J6" (8) .

7. Connect the "Hi Fuse" connector to terminal "J3" (5) .

8. Connect the "Lo Fuse" connector to terminal "J4" (4) .

9. Calibrate the DC voltage. Proceed to Testing and Adjusting, "DC Voltage - Calibrate".