5-4
APPLYING LOAD
Allow the set to warm up before connecting a heavy load.
Continuous generator overloading may cause high oper-
ating temperatures that can damage the windings. Keep
the load within the nameplate value for normal operation.
Carbon deposits may form on the exhaust system during
operation at light loads; apply full load occasionally be-
fore shutdown to prevent excessive carbon accumula-
tions. When possible, connect the load in small incre-
ments, instead of fully loading the genset at once.
EXHAUST SYSTEM INSPECTION
Make regular inspections of the exhaust system. If you
notice a change in the sound or appearance of the ex-
haust system, shut the unit down immediately and have it
inspected by your Onan dealer or distributor.
Exhaust gas presents the hazard of se-
vere personal injury or death. Inspect the exhaust
system audibly and visually each day. With the gen-
erator set running, momentarily open the access
cover to inspect the muffler. Have any leaks repaired
immediately.
BREAK-IN PROCEDURE
Continuous generator set overloading
can cause high operating temperatures that could
damage the generator windings. Keep the load
within the nameplate rating.
Observe the following schedule for genset break-in:
1. One half hour at 1/2 load.
2. One half hour at 3/4 load.
3. Full load.
Do not run the generator set continuously under one half
load during the first few hundred hours of operation. This
usually results in poor piston ring seating, causing
higher-than-normal oil consumption and blowby.
Drain and replace the crankcase oil after the first 50
hours of operation. Do this while the engine is still hot.
SAFETY DEVICES
In case of dangerously low oil pressure (below 14 psi [97
kPa]), the cutoff switch (LOPCO) stops the unit. After an
emergency stop, investigate and correct its cause. Press
the reset button on the control panel before restarting.
Hot oil can cause severe personal in-
jury. Do not check the oil level while the generator
set is running; wait until the generator set is cool be-
fore investigating.
EXERCISING UNIT
Infrequent use of the generator set can cause it to dete-
riorate. The following can occur:
•
Condensation in the fuel and lubrication system,
causing contamination and/or corrosion
•
Loss of protective oil film on moving engine parts
•
Loss of engine fuel prime due to drain-back and/or
evaporation
•
Battery discharge due to internal and external cur-
rent leakage
•
Breakdown of generator insulation due to water ab-
sorption
Proper exercising does the following:
•
Elevates engine oil temperature to at least 180
°
F
(82.2
°
C)
•
Evaporates water from engine lubrication system
•
Reestablishes a protective oil film on engine parts
•
Recharges battery to full normal potential
•
Brings generator to normal operating temperature
through load application
The generator set should be exercised at least once each
week: the engine oil temperature should be held at 180
°
F
(82.2
°
C) for at least 30 minutes during this exercise.
To exercise the generator set, do the following:
1. Perform all required maintenance checks, start the
unit, and apply a load by creating a simulated power
failure*. This exercises the control and switchgear
systems.
2. Apply at least 50 percent load, using the thermos-
tatic shutters if needed, to heat the engine and gen-
erator, as described above.
3. Exercise the unit long enough to provide at least 30
minutes running time at normal operating tempera-
tures. This requires at least 60 minutes total running
time.
4. Shut the unit down by simulating the return of nor-
mal power*. Run the set for approximately 10 min-
utes with no load to allow the engine to cool down.
* This applies to a standby genset only. Other units
should be started and loaded by control and load
application systems normally associated with op-
eration of the unit.
