Clarke PC20 Operating & Maintenance Instructions page 9

Typical Wiring Diagram for 230V to 400V Phase Converter
NOTES:
• Please take into account the various losses which are incurred in the
conversion from single to three phase supply. It will be necessary to select an
output from the Converter which is greater than the rated power of the motor
being driven. Ensure also the wiring to the motor is of sufficient size so as not to
incur losses.
• If the machine, which is to be fed from the converter, has a contactor starter,
it should be noted that the control circuit should be fed from the two live
phases (pins 'L1' and 'L3 in the socket). Should the contactor chatter or not
operate at all, this indicates that the control circuit is not fed from lines 'L1'
and 'L3'.
• If the control circuit is designed for 230 volts AC, a separate feed for the control
circuit must be provided. Consult a qualified technician if in doubt.
• When using the converter with multispeed machines, care must be taken
to allow the machine to slow down before switching from high to low speeds,
if this procedure is not followed, the excess motor, back E.M.F. could damage
both the converter and motor.
• When reversing motors, ensure that the motor has stopped fully before doing
so.
• For some applications of small motors, or motors of unusual magnetic
characteristics, it may be necessary to provide a pilot motor to obtain a
balance of phases. Generally the pilot motor should be a 2 pole (2800 rpm)
motor and as a general guide should be at least twice as big as the motor to
be driven.
If necessary, consult a qualified technician
Standard on-line starting.
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