TOOLS NEEDED     | ||
Part Number     | Tool     | Quantity     |
6V-7070     | Multimeter     | 1     |
Six-Diode Rectifier Block
Illustration 1 | g00613957 |
Six-Diode Rectifier Block (one piece) (1) Positive Rectifier Block (2) Negative Rectifier Block (3) Rectifier Terminal "AC1" (4) Rectifier Terminal "AC2" (5) Rectifier Terminal "AC3" |
The following procedure tests all six diodes within the block. If any meter reading does not fall within the given ranges, replace the rectifier block.
- Set the digital multimeter on the diode range. Remove all leads from the rectifier block.
- Place the black test lead on the positive "+" rectifier terminal. Place the red test lead on the following rectifier terminals: "AC1" (3), "AC2" (4) and "AC3" (5). All readings on the meter should be between 0.4 and 1.0 ohms.
- Place the red test lead on the negative "-" rectifier terminal. Place the black test lead on the following rectifier terminals: "AC1" (3), "AC2" (4) and "AC3" (5). All readings on the meter should be between 0.4 and 1.0 ohms.
- Place the red test lead on the positive "+" rectifier terminal. Place the black test lead on the following rectifier terminals: "AC1" (3), "AC2" (4) and "AC3" (5). In all cases, the meter should read "OL" (overload).
- Place the black test lead on the negative "-" rectifier terminal. Place the red test lead on the following rectifier terminals: "AC1" (3), "AC2" (4) and "AC3" (5). In all cases, the meter should read "OL" (overload).
Note: A shorted diode can cause damage to the exciter rotor. If a diode is shorted, check the exciter rotor. Refer to the Testing and Adjusting, "Winding - Test" and Testing and Adjusting, "Insulation - Test". Perform these tests.
Note: This rectifier block also contains varistor CR7. CR7 can be checked by measuring the resistance between the positive "+" rectifier terminal and the negative "-" rectifier terminal. The resistance should be a minimum of 15000 ohms.
Two-Diode Rectifier Block
Illustration 2 | g00610186 |
- Set the digital multimeter on the diode range. Remove all leads from the rectifier block.
- Place the black test lead on the AC rectifier terminal.
- Place the red test lead on the negative "-" rectifier terminal. The reading on the meter should be between 0.4 and 1.0 ohms.
- Place the red test lead on the positive "+" rectifier terminal. The reading on the meter should be "OL" (overload).
- Place the red test lead on the AC rectifier terminal.
- Place the black test lead on the negative "-" rectifier terminal. The reading on the meter should be "OL" (overload).
- Place the black test lead on the positive "+" rectifier terminal. The reading on the meter should be between 0.4 and 1.0 ohms.
Note: A shorted diode can cause damage to the exciter rotor. If a diode is shorted, check the exciter rotor. Refer to the Testing and Adjusting, "Winding - Test" and Testing and Adjusting, "Insulation - Test". Perform these tests.