Usage:
Procedure A - Check Engine RPM (Frequency)
Procedure B - Adjust Voltage Level
The voltage level adjustment range must be within +10 to -25% of rated voltage.
- * If the voltage level cannot be adjusted as described:
a. Check accuracy of voltmeter.
b. Go to Procedure C.
Procedure C - Check AC Voltage Between Regulator Terminals 20 And 22
Check the jumper for selecting 50/60 Hz operation. For 60 Hz operation, a jumper is required from terminal 6 to terminal 10.
- * If voltage is above 200 volts for a 240V or 600V generator, or above 390 volts for a 480V generator, or above 100 volts for medium voltage generators (120 volt sensing):
Check meters.
- * If voltage is lower than 200 volts for a 240V or 600V generator, or lower than 390 volts for a 480V generator, or lower than 100 volts for medium voltage generators (120 volt sensing):
Go to Procedure D.
- * If voltage is lower than 200 volts for a 240V or 600V generator, or lower than 390 volts for a 480V generator, or lower than 100 volts for medium voltage generators (120 volt sensing):
Procedure D - Isolate Regulator
Disconnect leads from regulator terminals F1 And F2. Connect a 12 volt automotive type battery across exciter leads F1 (+) and F2 (-). Operate generator at half of the rated speed. Then slowly increase RPM.
- * If voltage at regulator terminals 20 and 22 is less than 100 volts, shutdown the generator and:
a. Check rotating rectifiers CR1-6 (rotating rectifier block).
b. Check surge suppression diodes CR7-8 (varistors).
c. Check exciter stator L1 resistance between F1 and F2 leads. Exciter stator resistance should be approximately 3 to 5 ohms.
NOTE: For more information, see SR4 Generator Service Manual, Form No. SENR3985.
- * If balanced AC voltage between regulator terminals 20-22-24 and not balanced between terminals 26-28-30 that increases with rpm:
Check permanent magnet PM exciter voltage. Disconnect wires 12 and 13, that go to the PM exciter. Check the PM exciter between wires 11-12-13 for a balanced voltage increasing with speed and greater than 50 VAC at rated speed.
- * If balanced AC voltage between regulator terminals 20-22-24 and between terminals 26-28-30 that increases with rpm:
Go to Procedure E.
- * If balanced AC voltage between regulator terminals 20-22-24 and not balanced between terminals 26-28-30 that increases with rpm:
Procedure E - Isolate Attachments
Connect exciter stator L1 leads to regulator terminals F1 and F2. Disconnect all attachments such as manual voltage control, remote voltage control, droop transformer, etc.
NOTE: If remote mounted voltage adjustment is disconnected, connect jumper across terminals 4 and 7.
Check all connections to the regulator and the regulator fuses.
- * If generator output voltage is normal:
Check attachments.
- * If voltage at regulator terminals 20 and 22 cannot be adjusted to rated voltage at rated frequency with no load:
a. Check the jumper for selecting 50/60 Hz operation. For 60 Hz operation, a jumper is required from terminal 6 to terminal 10.
b. Replace regulator.
c. Bench test the regulator; see Bench Test.
- * If voltage at regulator terminals 20 and 22 cannot be adjusted to rated voltage at rated frequency with no load: