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Old 23rd January 2014, 07:10 AM
beardydave beardydave is offline
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Join Date: Oct 2012
Location: Fareham
Posts: 73
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Don't need capacitors with a 3-phase motor, the capacitors are to provide power for longer tokeep the motor turning at start up.

just wire the brown, black and grey supply wires (red, yellow and blue if its an old installation) with a 3 pole switch and a fuse or mcb for each phase directly to the u1 v1 and w1 one the motor. You need to size your cables for about 7x the full load current (flc) to cope with the spike in current when the motor is started, but the fuses should be set to just above the flc.

if the compressor has any remaining single phase controllers on it use one of the phases and run a neutral wire as well.

Do you have a switched 3-phase or 3-phase+neutral socket on the wall? That would provide the switch and would imply that the circuit has already got circuit breakers.
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