Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B Service Manual page 151

F-91
STATIC CAPACITOR BALANCE TEST (continued)
WARNING
ELECTRIC SHOCK
can kill.
With input supply power ON,
there are high voltages
inside the machine.
machine or touch any internal part of the
machine, including resistors R9 and R10. Use
insulated gloves to measure the resistance
across these resistors.
9. Turn input supply power to the machine
ON. Machine output must be OFF.
10. Measure and record the DC voltage
across bleeder resistors R9 and R10.
Compare the voltage recorded to the
desired values in Table F.7, depending on
the input supply voltage setup.
11. Determine the difference between the two
bleeder resistor voltages.
VAC INPUT
460 VAC
440 VAC
415 VAC
380 VAC
230 VAC
208 VAC
TROUBLESHOOTING & REPAIR
Do not reach into the
TABLE F.7
BLEEDER RESISTOR R9 AND R10 VOLTAGE VALUES
VDC ACROSS BLEEDER RESISTORS R9 AND R10
POWER WAVE 450
For 380 VAC Input Voltage or Higher:
If the difference is less than 75 VDC, static
capacitive balance is okay.
If the difference is more than 75 VDC, sta-
tic capacitive balance is not okay. Perform
the Input Rectifier Test.
check input filter capacitors C1, C2, C3,
and C4 for any signs of damage; replace
the FET or IGBT assembly.
For 220 VAC Input Voltage:
The two resistance measurements should
be the same. If one or both is less than
175 VDC, perform the Main Contactor
Test and the Input Rectifier Test. Also
visually check input filter capacitors C1,
C2, C3, and C4 for any signs of damage;
replace the FET or IGBT assembly.
12. After the test is completed and the prob-
lem successfully repaired, install the
machine case sides and top.
13. Install the handle and the lift bail rubber
gasket.
325 VDC
311 VDC
293 VDC
269 VDC
325 VDC
294 VDC
F-91
Also visually