KIT-PISTON SEAL 3750750 - Caterpillar

Problem 2 - - Low AC Voltage
Procedure A - Check Engine RPM (Frequency) Procedure B - Adjust Voltage Level With Gain Adjustment Full CounterclockwiseThe 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* 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. Procedure D - Isolate RegulatorDisconnect 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. 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 then 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. Procedure E - Isolate AttachmentsConnect exciter stator L1 leads to regulator terminals F1 and F2. Disconnect all attachments such as manual voltage control, remote voltage control, droop transformer, etc. 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 and rated frequency at no load: a. Replace regulator.b. Bench test the regulator; see Bench Test.Problem 3 - - High AC Voltage
Procedure A - Check Engine RPM (Frequency) Procedure B - Adjust Voltage Level With Gain Adjustment Full CounterclockwiseThe 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 Fuses Located On Regulator* If fuse(s) have failed: Look for possible short circuits that could cause fuse failure such as shorted exciter stator L1, etc.* If fuse(s) are okay: Go to Procedure D. Procedure