Lincoln Electric PRO-CUT 55 SVM140-A Service Manual page 59

F-22
PRIMARY POWER BOARD RESISTANCE TEST AND
6. Check for the appropriate voltages outlined
in Table F.3.
NOTE: Voltages may vary with the input line
voltage.
NOTE: If the capacitor voltage is too high
(over 400 VDC) or too low (less than 220
VDC) the control board will deactivate relay
CR1. This will prevent output.
NOTE: If Capacitor C1 is found to be defective, both Capacitors C1 and C2 must be replaced
TROUBLESHOOTING & REPAIR
CAPACITOR VOLTAGE TEST (continued)
TABLE F.3 - CAPACITOR VOLTAGES
INPUT APPLIED
460VAC
440VAC
415VAC
380VAC
at the same time. The capacitors must be replaced in matched sets.
PRO-CUT 55
7. If the test voltages do not meet the expect-
ed values as listed in Table F.3, the capaci-
tors or other components on the power
board may be faulty. Replace.
NOTE: If the capacitor voltages are NOT bal-
anced within 20 VDC, the capacitors may need
"conditioning." See the Maintenance section.
EXPECTED VOLTS
DC AT CAPACITOR
TERMINALS
325VDC
311VDC
293VDC
269VDC
F-22