Hobart GPU-600 Series, Operation And Maintenance Manual

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OM-2244 / Operation and Maintenance Manual
DCS-600/ Series 500082 / Solid State Transformer-Rectifiers
December 15, 2014 Chapter 2-1
Page 7
c. Ambient temperature too high Operate at reduced loads when
temperature exceeds 104° F (40°
C) or improve cooling ambient.
d. Ventilation blocked Check that air intake and exhaust
openings are not obstructed.
e. Fan not operating Check fuse F1 on the fan shroud. If
it is good, disconnect the fan motor
leads and apply 115 VAC directly
to fan motor. Replace fan motor if it
fails to operate or if its bearings are
defective.
f. Shorted output Reset electronic overload.
2. Over-voltage/Overload trip
malfunction is in unit’s internal
circuitry. a. Control circuit board failure Refer to detail troubleshooting
instructions.
b. Loose connections in voltage
control circuit Check for loose connections.
Tighten and secure as required.
c. Starting current potentiometer
(R13) open Replace potentiometer.
3. Fan not operating (also see
causes and remedies under
“Machine will not start”) a. Blown fuse (F1) Replace fuse.
b. Fan control thermostat defective Place a jumper wire across the
overheated thermostat. If fan then
runs, replace thermostat.
Note: A properly operating fan thermostat will turn on the fan at 100°F
and keep the fan running until 80° F is reached at heat sink.
c. Broken lead or connection to fan
motor Repair wiring as necessary.
d. Fan motor defective
Disconnect fan motor leads and
apply 115 VAC directly to fan
motor. If it fails to operate, replace
it.
Trouble, Symptom, Condition Probable Cause Test, Check, and/or Remedy
Voltage on GPU Case
1. Operator gets shock when
machine case is touched a. Case of machine not grounded Ground machine case to an earth-
type ground if utility ground is
already connected. Connect the
normal safety ground and recheck
if “utility” ground had not been
connected.
Output Current Varies Without Voltage Change