ESAB Aristo Arc 4000i, Service Manual

Page: 63 / 78

S0740 800 191/E080229/P78
Measure the voltage across the smoothing capacitors
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cp03f3soft
Measurements
Circuit diagram for soft starting measurements
1. Start the power source.
2. Measure the voltage on 15BR1. It
should be about 15 V DC. See the
circuit diagram above.
3. Measure the voltage between the
negative terminal on capacitor C16
and the positive terminal on capacitor
C14, on circuit board 15AP1. It should
be about 13.8 V DC.
4. Measure the voltage across
capacitors C16 and C14 respectively.
It should be about 6.9 V DC.
5. Use ESAT to set a current reference.
6. Using an oscilloscope, examine the waveforms on the
secondary side of TM1, at the inputs to diodes 15D1 and
15D2. Make the connection as shown in the picture on the
right.
The pulses must look like this:
Output voltage waveform from TM1 for soft starting
Test points for the secondary
voltage from TM1
7. Using a multimeter, check that the DC voltage at the welding terminals is about 2.9 V.
8. If all the measurements are as described above, reconnect the wires to restore the
power source to normal operation mode and make a test weld.