Hobart Jet-Ex 5D Operation And Maintenance Manual page 67

OM-2094 / Operation and Maintenance Manual
Jet-Ex 5D / Series 500285 / Generator Set
Generator and Controls (continued)
See section 2-4 for all figures referenced in this section.
Trouble, Symptom and Condition
Load contactor will not close
when CONTACTOR
CONTROL toggle switch S408
(7, Figure 4) is placed in closed
position. Engine running
normally, voltage normal, no
load applied to output cable
(continued)
5. Load contactor opens as soon
as CONTACTOR CONTROL
toggle switch S408 (7, Figure
4) is released from its top
(spring-loaded) position, to Run
position.
6. Load contactor K402 opens
during power delivery.
November 1, 2000
Revised 03/01
Probable Cause
c. Overvoltage relay K403
defective.
a. Defective CONTACTOR
CONTROL toggle switch.
b. c. Load contactor K402
defective.
a. Contactor opening could
have been normal because
of an overvoltage condition.
b. Overvoltage relay K403
defective.
c. Overvoltage board out of
adjustment.
d. Load contactor K402
defective.
Test, Check, and Remedy
Connect a jumper lead between
terminals T and P on the
overvoltage relay (1, Figure 5). If
contactor will now close, replace
overvoltage relay.
Connect a jumper lead between
terminals with red and blue
wires on the CONTACTOR
CONTROL toggle switch. If the
load contactor now remains
closed, replace contactor close
switch.
If no fault was found in steps 4-a
and b, the load contactor (10,
Figure 1) is probably defective.
Replace load contactor.
Resume operation and closely
observe VOLTMETER (3,
Figure 4) for evidence of
overvoltage. If contactor opens
when no overvoltage condition
exists, proceed to Step b.
Check overvoltage relay by
operating the machine under
load and gradually raising
voltage at the voltage regulator
(2, Figure 5) while observing
VOLTMETER (3, Figure 4).
Start with a low voltage (25V
DC) and gradually increase
voltage until relay functions to
open load contactor. (32 to 34V)
If relay trips at less than 32-V
DC, adjust potentiometer (P1)
on the overvoltage board
(1, Figure 5). If this does not
correct problem, return old
board to factory for service.
If no fault was found in above
steps, replace load contactor
(10, Figure 1)
Chapter 2-5
Page 7