COUPLING 8S7169 - Caterpillar

Power Distribution Board (PWD) Description
Illustration 1 g01276398
(1) Power distribution boardThe power distribution board (PWD) is located on the upper left panel of the flywheel cabinet.The PWD distributes all power (24 VDC) to the following components: boards (MMU), vacuum pump, fans and controls.The lower left panel of the Flywheel cabinet contains the "T1" transformer for the flywheel. "T1" power is fed from the circuit breaker that is located on the lower left panel of the flywheel cabinet.Removal Procedure
Refer to Systems Operation, Testing and Adjusting, RENR9988, "Internal Component Pre-removal Steps (Flywheel Cabinet)" in order to shut down the system and gain access to internal components.
Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in a static-shield bag. Follow these guidelines when you handle any module:Touch a grounded object to discharge static potential.Wear an approved wrist-strap grounding device.Do not touch the bus connector or connector pins.Do not touch circuit components inside the module.If available, use a static-safe work station.
Remove the static switch assembly in order to access the board (1) . Refer to Systems Operation, Testing and Adjusting, RENR9988, "Static Switch" for the removal procedure.
Illustration 2 g01277014
PWD Connections
Disconnect all connectors from the board (1) . Verify each label for each connector for subsequent installation. Refer to Illustration 2 for wire connections.
Disconnect the nine white plastic standoffs that connect the board (1) to the left panel.Note: The board (1) must be removed from the standoffs without bending the board (1) .
Compress the head of each standoff so that the board (1) is not locked, but the board (1) is still attached to the standoff.
Remove the board (1) from all standoffs at the same time.Installation Procedure
Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in a static-shield bag. Follow these guidelines when you handle any module:Touch a grounded object to discharge static potential.Wear an approved wrist-strap grounding device.Do not touch the bus connector or connector pins.Do not touch circuit components inside the module.If available, use a static-safe work station.
Position the board (1) in the cabinet over the white standoffs that are connected to the left panel. Install the board (1) . Verify that all the standoffs are locked into the correct position.
Connect the wire connectors. Verify the labeling of each connector for proper placement. Refer to Illustration 2.