Kemppi Mastertig MLS 3003 ACDC Service Manual page 28

Measurements
TESTING OF THE SECONDARY OVER VOLTAGE WATCH
1. Connect MLS- Service power voltages (24+24+50)Vdc in series by using PTC-resistor.
2. Set the machine to DC- TIG mode.
3. Connect the test voltage to output DIX terminals of the machine.
4. If machine shows "Err 6" then it is OK.
5. Repeat the test with reversed polarity.
24 VDC 24 VDC
PTC
50 VDC
PTC
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