Red-D-Arc D502K 5+4, Technical Manual

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TM-4412 Page 47 D502K 5+4
10-8. Using Diagnostic LED’s On LED Board PC9
The LED’s on circuit board PC9 monitor all critical input voltages to field current
regulator board PC1.
If PC9 Power LED, Output On/Off LED, and AC Input LED are on with
Process/Contactor Control switch S6 in Weld Terminals Always On - CC Stick
mode and engine running at weld/power speed, 89 volts dc should be present at
brush leads 105 and 108. This indicates field current regulator board PC1 is
functioning normally.
NOTE
a) Condition – no load; weld/power
rpm unless noted
b) Voltage/Amperage Adjust Con-
trol switch S5 in Panel position
b) Reference – to circuit common
(lead 42) unless noted
LED Status Self-Test
POWER On Ind12 volts dc is present to energize PC1.
Off If LED is off:
Check control relay CR5 for proper coil voltage and connections. Check continuity of coil and condition
of contacts. Replace CR5 if necessary.
Reset circuit breaker CB10 and/or CB11.
Check for loose electrical connections to PC1.
Check for 12 volt dc supply voltage to PC1. If voltage is low, check battery or engine charging system.
OUTPUT
ON/OFF
On Indicates 24 volts ac input with Process/Contactor Control switch S6 in Weld Terminals Always On posi-
tion, or with S6 in a Weld Terminals Remotely Controlled position with remote contactor closed.
Off If LED is off:
Place Process/Contactor Control switch S6 in Weld Terminals Always On position, or place S6 in Weld
Terminals Remotely Controlled position and connect remote contactor to remote receptacle RC14.
Reset circuit breaker CB5.
Check filter board PC6 and connections, and replace if necessary (see Section 10-5).
COMMAND On Indicates 0 to +10 volts dc input from min. to max. of Voltage/Amperage Adjust control R1 with Voltage/
Voltage/Amperage Adjust Control switch S5 in Panel position.
Off If LED is off:
And Power LED is on, check that Voltage/Amperage Adjust control R1 is not at min.
And Power LED is on, check and tighten connections to Voltage/Amperage Adjust control R1.
And Power LED is on, check voltage at Voltage/Amperage Adjust control R1 (see Section 10-2). If correct
voltage is not present, check connections to PC1.
And Power LED is on, check resistance and connections of Voltage/Amperage Adjust control R1; R1 is
0 to 1000 ohms
±
10%. Replace R1 if necessary.
RPM
LIMIT
.
LED normally
off at weld/
power speed)
On Indicates engine speed is less than 1704 rpm (approximately).
If LED is on:
And AC Input LED is on, check engine weld/power speed and adjust if necessary.
And AC Input LED is off, check fuse F2, and replace if open.
And AC Input LED is off, reset circuit breaker CB12.
Off Indicates engine speed is above 1704 rpm (normal operation).
AC INPUT On Ind 175 volts ac input from field excitation circuit.
Dim or Off If LED is off, power LED is on, and normal ac voltage is present at ac receptacles (see Section 10-2):
Check fuse F2, and replace if open.
Reset circuit breaker CB12.