If symptoms of poor performance develop, the following
chart can be used as a guide to correct the problem.
When diagnosing faults in operation of the hydraulic
motor generator, always check that the hydraulic
power source is supplying the correct hydraulic flow and
pressure to the alternator as listed in the table. Use a
flowmeter known to be accurate. Check the flow with the
hydraulic oil temperature at least 80°F/270C.
Hydraulic motor generator does
Hydraulic power source not
Check power source for proper
flow and pressure (7-9 gpm/26-
34 Ipm, 1000-2000 psi70-140
Couplers or hoses blocked.
Locate and remove restriction.
Hyrevz motor failure.
Inspect and repair.
Hydraulic lines not connected.
No electrical output.
Open circuit breaker.
Reset circuit breaker.
Loose or broken wires.
Locate and repair.
Loss of residual magnetism.
Flash the Field.
1. Stop the generator.
2. Remove the receptacle
panel (2, figure 2).
3. Using a 12 volt automotive
battery, touch the positive lead
to the end of the diode set with
the white or silver band located
on the rotor assembly. At the
same time touch the negative
lead to the opposite end of the
diode set. Hold the leads
across the diode set for 2-4
NOTE: Do not reverse the
polarity of the leads. This may
cause damage to the diodes or
the rotor or both.
3. Replace the receptacle panel
and start the generator.
Short circuit in rotor field or rotor
Return the unit to Authorized
Shorted AC or exciter stator
Check with ohmmeter. Continuity
should exist from black to
white wires and also from red to
red wires. No continuity should
exist from either black or
whitewire to red wire or from
any wire to ground. If a short
circuit is detected, replace the