Section 7
DIAGNOSTIC TESTS
line voltage should read between
4.Turn the governor adjusting screws to obtain a
TEST 3- TEST EXCITATION CIRCUIT
BREAKER
DISCUSSION:
This circuit breaker (CB2) is normally closed and self- resetting. It will open in the event of excessive current from the Stator excitation (DPE) winding. The circuit breaker should
When the breaker ( CB2) is open, excitation current to the Regulator (and to the Rotor) will be lost. The unit's AC output voltage will then drop to a value that is equal to the Rotor's residual magnetism (about
PROCEDURE:
Note: After running the unit, allow two minutes for the breaker to reset.
1.Set a
2A | 2 |
|
2A
CB3
2
A. Schematic | B. Pictorial |
Figure 7-2. – Excitation “DPE” Circuit Breaker
2.In the generator panel, locate the excitation circuit breaker. Disconnect Wire 2 and Wire 162 from the breaker terminals.
3.Connect the meter test leads across the two circuit breaker (CB3) terminals. The meter should indicate “continuity”.
RESULTS:
1.If the meter did NOT read “continuity”, replace the excitation (DPE) circuit breaker (CB2), and go to Test 4.
2.If “continuity” was indicated, go to Test 4.
TEST 4- FIXED EXCITATION TEST/ROTOR
AMP DRAW
DISCUSSION:
The fixed excitation test consists of applying battery voltage (12 VDC) to the Rotor windings. This allows that portion of the excitation circuit between the Voltage Regulator and the Rotor (including the Rotor itself) to be checked as a possible cause of the prob- lem. When battery voltage is applied to the Rotor, the resulting magnetic field around the Rotor should induce a Stator power winding voltage equal to about
CONNECT POSITIVE (+) |
| WIRE NO. 4 | |||
| TO ROTOR | ||||
BATTERY SUPPLY |
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11 |
| AND TO ECB | |||
TO WIRE #4 | 22 | ||||
| 0 |
| |||
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| 6 | ||
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|
| ||
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|
|
| 162 |
VOLTAGE
REGULATOR
TERMINALS
Figure 7-3. – Fixed Excitation Test
PROCEDURE:
1.Disconnect Wire 4 from the Voltage Regulator (VR). (Third ter- minal from the top of VR).
2.Connect a jumper wire to Wire 4 and to the 12 volt fused battery positive supply Wire 15 (Wire 15 located at fuse (F1) holder).
3.Set the VOM to measure AC voltage.
4.Disconnect Wire 2 from the DPE breaker (CB2) and connect one test lead to that wire. Disconnect Wire 6 from the Voltage Regulator and connect the other test lead to that wire. Start the generator and measure the AC voltage. It should be above 60 VAC. Record the results and stop the generator.
5.
connect Wire 6 to the Voltage Regulator.
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