ENGINE AR-PRIMARY 1885097 - Caterpillar

Personal injury or death can result from high voltage.When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.Improper test equipment can fail and present a high voltage shock hazard to its user.Use electrical safety gloves when you are working in the cabinets.Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made.
Table 1
TOOLS NEEDED
Part Number Tool Quantity
237-5130 Digital multi meter 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 F1 and F2 from the voltage regulator. Disconnect the generator load.
Connect a 12 VDC automotive type battery to wires F1+ and F2-.
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. Note: The sensing leads of the VR can be used for the generator set test on the secondary of the PT.
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 %. "T1" and "T2"
"T1" and "T3"
"T2" and "T3"
Increase generator set speed by 10 %.
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 %. Do not exceed half of the rated speed.
The measured voltages of Step 4 should be at least 85 VAC. With a 10 % 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 %. 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.