Engine Accessories Adjustment; Basic Engine Adjustments - Hobart 90CU24 Operation And Maintenance Manual

OM-2084 / Operation and Maintenance Manual
90CU24 / Series 500392 Generator Sets
• Connect the generator set output cables to a load. Load the generator set with the largest
available three-phase load of rated power factor not exceeding the maximum rating of the
generator set.
• Measure output voltage at the load end of the cables. If the load voltage rises or drops
more than 1% at the load end of the cables, decrease or increase the line drop
compensation until the regulation is flat (115-V AC line-to-neutral and 200-V AC
line-to-line).
• If the line drop compensation adjustments have affected the no-load voltage output, adjust
the fine output voltage control potentiometer (37, Fig. 1) to the desired value.
(2) Test the Voltage Regulator
After necessary adjustments have been completed, re-test the voltage regulator as follows:
a. Connect a voltmeter at the load end of the generator output cables.
b. Operate the generator set at no-load and observe voltage reading.
c. Operate the generator set under load and observe voltage reading.
d. Voltage under load should vary no more than 1% at the load end of the cables from voltage
under no-load.
c. Basic Engine Adjustments
Adjustment procedures applicable to the diesel engine are included in the Cummins Operation
Manual, which is located in Chapter 5. Specific information for these engines is listed in Figure 2.
Refer to the Cummins Operation and Manual for detailed information on the following engine
adjustments.
(1) Exhaust valve adjustment
(2) Fuel injector timing adjustment
(3) Engine idle speed adjustment
Engine idle speed is set at the factory. The adjustment is then sealed to discourage tampering.
Idle speed should not be changed by the user. If adjustment is required, contact the local
Cummins Distributor. The recommended idle speed is 750 +/- RPM.
NOTE: A stroboscope is required for engine idle speed checks.
(4) Engine speed limiting adjustment
The speed limiting adjustment is also set and sealed at the factory. Speed should be limited to
2750 +/- 75 RPM. If adjustment is required, contact your local Cummins Distributor.
d. Engine Accessories Adjustment
(1) Alternator and fan belt adjustment
Refer to 2-2, Par. 6 for belt adjustment instruction.
Chapter 2-3
Page 10
November 27/1997