GEAR 3P0330 - Caterpillar

SPTS SWITCH INSTALLED IN SERIES IN WIRE (24).Example: If an electric set is rated for 240 volts at 1800 rpm (60 hertz), it will generate 160 volts at 1200 rpm (40 hertz).Run the engine at high idle rpm and close the switch for a moment. Read the line voltage while the switch is closed. If the line voltage is approximately the same as rated voltage, the regulator module is working correctly. If the failure condition does not change, the regulator module can have a defect.Procedure For First Operation After Repair
Do not run the electric set at rated rpm immediately after repair. The following procedure can prevent new failures if the CAUSE of the first failure condition was not correctly found.1. Disconnect wires (10 and 19) from regulator assembly (A1). Cover the terminal of wires (10 and 19) with insulation tape.2. Start the engine and run it at 1200 to 1250 rpm. The residual magnetism in the exciter field (L3) and the rotating field (L5) will give approximately 3 to 4 volts as measured at terminals (20) and (22). If the controlled rectifier has a short circuit, the generator will give a higher output voltage. Install a new controlled rectifier (CR9).3. Stop the engine and connect wires (10 and 19) to spade terminals (10 and 9) of regulator assembly (A1).4. Start the engine and run it at 1200 to 1250 rpm. The output voltage will be approximately 67 to 70 percent of the generator rated voltage. If the output voltage is too high (much higher than 70 percent of rated voltage), the failure is probably in the regulator module (A1).5. With the engine running at a low idle rpm and the generator giving a constant voltage (approximately 60 to 70 percent of rated voltage), move the governor control to let the engine come up gradually to rated rpm. Make an adjustment to the voltage level control (R2) until the generator is at rated voltage. The generator is now ready to use.Flashing The Field
If the generator rotating field (L5) or the exciter field (L3) have a loss of residual magnetism, the magnetism can be put back by "flashing" the exciter field winding with a direct current 6 volt source. This source can be a 6 volt battery or a stationary battery charger.Dynamic Flashing (Engine Running)
With the engine stopped, connect a voltmeter (one with a high degree of accuracy) to terminals (20 and 22). Connect the positive "+" cable of the six volt source to terminal (F1). Start the engine and run at low idle rpm. Put the negative cable of the six volt source on terminal (F2) while reading the voltmeter. As soon as the voltmeter has an indication, remove the negative cable from terminal (F2). If the negative cable of the DC source is held on terminal (F2) too long, the generator voltage can become too high and cause fuse (F1) to open. An ON-OFF switch in the DC source makes the work safer and easier. If a battery