COMPRESSOR GP 7E6613 - Caterpillar

Illustration 2 g02164352
Set up for testing the generator stator windings
(1) High voltage cables disconnected and isolated from contact with the generator bus bars. Sections of thick wall rubber hose were used for this purpose.
(2) Red positive clip of the megger connected to a generator winding lug
(3) Black negative clip of the megger connected to a generator housing ground point (bolt head)
Disconnect the three high voltage cables from the generator phase bus bars.
Take note of the flat washer and belleville washer stack order for reinstallation.
The cable end connectors must be isolated from contact with the generator bus bars. Either remove the cables from the enclosure or insulate the cable ends as shown in illustration 2. Do not use hydraulic hose for the isolation. Hydraulic hose has metal under the covering.
To test generator stator windings:
Connect the megger red positive clip to one of the generator phase bus bars. All three stator windings are internally connected in the generator. Only one winding connection will need to be tested.
Connect the megger black negative clip to a good frame ground on the Generator housing such as a bolt head or other unpainted surface.
Set the megger test voltage to 1000 V. Ensure that all personnel are not in contact with any of the generator phase lugs or the megger clips.
Press the “START/STOP” button on the megger to start the test. Continue the test until the test voltage and the resistance reading have stabilized for 30 seconds. Record the displayed resistance measurement for the generator stator windings.
Press the “START/STOP” button to stop the test. The megger will discharge the system. Wait until the voltage readout on the megger display is 0 V.
After the testing is completed, reconnect the high voltage cables to the original connections on the generator.
Install the flat washers and belleville washers in the original stack order.
Torque the connections to 54.20 N.m (40.0 lb ft). Test the Generator Exciter Winding
The auxiliary enclosure is on the left-hand side of the Generator. To avoid having to remove the enclosure cover, the megger will be connected to the exciter winding circuits at the enclosure connector. The battery disconnect switch remains in the OFF position.
Illustration 3 g02164406
Exciter winding circuit connector on the front side of the generator auxiliary enclosure
At the front side of the generator auxiliary enclosure, disconnect the round 4 contact connector that contains the two exciter winding circuits.
Illustration 4 g02164433
The generator auxiliary enclosure exciter circuit connector
(4) Contact A - negative exciter winding circuit
(5) Contact B - positive exciter winding circuit
When the truck is in operation, the exciter circuits are energized to 144 VDC. Use a multimeter to measure for any DC voltage between the connector contact A (4) and contact B (5). Also measure between each pin and frame ground. If no voltage is present, continue to the next step.
To test the exciter winding:
At the disconnected exciter circuit connector, connect the positive megger clip to either the contact A pin (positive circuit) or the contact B pin (negative circuit). Use a spare 8 AWG connector socket with a