SPRING-GUIDE 2161598 - Caterpillar

Table 1
TOOLS NEEDED    
Part Number     Tool     Quantity    
237-5130     Digital Multimeter     1    
    12 V Battery     1    The generator set functional test is a simplified test that can be performed in order to determine if the generator is functional. The final test should be on the complete generator set while the generator is under load. The generator set functional test will determine if a phase voltage is being generated. The generator set functional test will also determine if the phase voltages are balanced. In addition, this test will determine if the phase voltages change with engine speed.The generator set functional test consists of the following steps:
Disconnect wires 5 and 6 from the voltage regulator. Disconnect the generator load.Note: The designations for the (L1) terminals will vary depending on the type of AVR. The VR6 uses "F1" and "F2" terminal labels. The R448 uses "E+" and "E-" terminal labels. The R450 has "F+" and "F-" terminal labels.
Connect a 12 VDC automotive type battery to wires 5 and 6. Refer to the previous note for exciter terminal designations.
Illustration 1 g02174208
(1) Exciter field (2) 12 V battery
Do not operate the generator set at a speed that is higher than one-half of the rated speed.Higher speeds under these test conditions can cause damage to the system.
Note: Do not allow the generator output voltage to exceed the nameplate rating.
Operate the generator set at half the rated speed.
Measure the AC voltage across the following terminals. Record the results.
Table 2
AC VOLTAGE ACROSS TERMINALS    
Generator Set Speed     Terminals     AC Voltage    
Half of the Rated Speed     "T1" and "T2"        
"T1" and "T3"    
"T2" and "T3"    
Decrease Generator Set Speed by 10 percent.     "T1" and "T2"        
"T1" and "T3"    
"T2" and "T3"    
Increase Generator Set Speed by 10 percent.
Do Not Exceed Half of the Rated Speed.     "T1" and "T2"        
"T1" and "T3"    
"T2" and "T3"    
Monitor the same voltages as Step 4, while decreasing and then increasing the generator set speed 10 percent. Do not exceed half of the rated speed.
The measured voltages of Step 4 should be at least 85 VAC. With a 10 percent increase in generator set speed, the voltages of Step 5 should show an increase of 10 percent. With a 10 percent decrease in generator set speed, the voltages of Step 5 should show a decrease of 10 percent.Note: If the engine speed cannot be adjusted to half of the rated speed, a 6 VDC battery can be used. The 6 VDC battery would be connected to wires F1+ and F2- in Step 2.Note: The designations for the (L1) terminals will vary depending on the type of AVR. The VR6 uses "F1" and "F2" terminal labels. The R448 uses "E+" and "E-" terminal labels. The R450 has "F+" and "F-" terminal labels.