Almost every permanent split capacitor and capacitor start capacitor run motor that I have seen has less current in the auxiliary winding that is connected in series with the capacitor than for the winding that is connected across the line.
A long cable will add some capacitance to the 180 uF in the control cabinet. Some of the capacitance will be in parallel with the 180 uF capacitor and will change the phase angle of the auxiliary winding. Some of the other capacitance will be to ground and essentially creates a T network that may or may not affect phase angle. The effect of the capacitance to ground will also be dependent upon system grounding method. Corner grounding and solidly ground wye systems and 4-wire delta systems produce different effects. Ungrounded places system capacitance is in series with auxiliary conductor capacitance to ground and ungrounded systems have a very high rate of motor damage due to static electricity buildup during rainstorms. An ungrounded system tends to reenact Benjamin Franklin's kite experiment and lightning arrestors for 480 volts ungrounded have a clamping voltage that is 200 to 800 volts above the 30 minute voltage withstand rating of a 480 volt motor. This is a bit how a Cleveland, Ohio police officer's bullet resistant vest did not work because the bad guy got lucky and sent a bullet up through the armpit. However, one way to get rid of static electricity on an ungrounded system is to use a ground detector that creates a direct current path through the primary windings of voltage monitoring transformers. Another way to combat static electricity particularly on the load side of a 480 volt motor controller is to connect 1 megOhm 5 watt resistors from each phase conductor to ground. What you can get are 240,00 Ohm 3 watt metal film resistors that have a peak voltage rating of 750 volts. You would use series strings of 4 of these per phase on 480 volts, 5 per phase on 600 volts, and 3 per phase on 240 volts.
If a motor is turned off for significant periods the load side of the motor controller needs static bleeder resistor regardless of system grounding method except 120 volts solidly grounded.
An alternative to conventional GFCI is to use a combination ground fault/ground check unit that does continuous monitoring of the equipment ground. The ground check circuit allow the ground fault relay to have a setting of 0.1 amps to 10 amps which will tolerate the leakage current of a 4,160 volt motor. One place that peddles these is
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The usual ground check circuit has a diode at the load end of the circuit that connects the ground check condutor to the machine frame using fasteners and lugs that are independent of the equipment ground. The diode is operated with the anode connected to the machine frame so that in high vibration applications a 50 amp diode can be used for mechanical ruggedness. The ground check relay uses either a 12 volt transformer winding or alternate connection to the +12 volt and -12 volt analog power to do 2 different continuity checks. The positive ground continuity check checks the integrity of the equipment ground. The application of negative ground power to the ground check conductor checks for ground faults in the ground check conductor.
If the power system is solidly grounded or ungrounded you will also need to put a fused telephone protector block in the ground check conductor to protect the ground check relay frommthe voltage drop in the equipment ground that will occur curing a ground fault. A ground fault/ground check relay as is is approved for resistance grounded systems where the first ground fault is limited to on the order of 1 to 20 amps. The level of ground fault current on a resistance grounded system will not create enough voltage drop in the equipment grounding conductor to affect the ground check relay.
You will need type G-GC cable for this application. This contains 3 or 4 large power wires and the same number of smaller wires in the case of the unshielded version. One of the small wires is used for the ground check circuit and the others are paralleled to make u0p the equipment ground.
Mike Cole