Power Pc Board Single Phase Detection (0558038315) - ESAB Powercut 1600 Service Manual

SECTION 4 DESCRIPTION Of OPERATION

4.10.6 Power PC Board Single Phase Detection (0558038315)

The power board monitors the the input power for loss of a phase when in three phase operation. This is
important as the microcontroller monitors the output duty cycle of the machine. The PC1600 is rated for
60% duty cycle at 90 amps of output current in three phase operation, and 40% duty cycle at 90 amps of
output current in single phase operation. Should the unit exceed the duty cycle, the microcontroller will shut
the machine down when the duty cycle limit is reached to prevent damage to the machine.
The single phase detection circuit monitors the output of T6. The AC voltage here is rectified by full wave
bridge D13. The output is then filtered by C61 and passed to the power board microcontroller as signal
mains_current.. A loss of voltage at T6 results in the loss of the mains_current signal. This loss tells the
micro control that the unit has lost a power input phase.
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