Using Diagnostic Led's On Led Board Pc9 - Red-D-Arc D502K 5+4 Technical Manual

10-8. Using Diagnostic LED's On LED Board PC9

NOTE
LED Status
POWER On
Off
OUTPUT On
ON/OFF
Off
COMMAND On
Off
RPM On
LIMIT
.
LED normally
off at weld/
power speed)
Off
AC INPUT On
Dim or Off
D502K 5+4
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.
Indicates +12 volts dc is present to energize PC1.
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.
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.
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).
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.
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.
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.
Indicates engine speed is above 1704 rpm (normal operation).
Indicates + 175 volts ac input from field excitation circuit.
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.
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
Self-Test
TM-4412 Page 47