Thanks for the responce.
My RPC is voltage balanced via CAPs to 236-232-228VAC.
The generated phase has a voltage drop from 228VAC to 156VAC when either my grinder or mill spindle motor is started. The supply voltage of 236VAC barely flucuates.
The CNC with a problem is a EDM WIRE machine. It is currently set up for 220VAC 3 phase. No neutral. It's Japanese so there is another transformer inside that converts the power to 200VAC 3 phase. Asside from the Pumps and the discharge circuit which use all three phases. THere are two other taps used for the PC and Servo Power. Each one is drawn from a different phase. As currently wired I get a MC Power Failure when the generated leg drops voltage. If I rotate the phases, and start my mill I get a PC power failure. Either Power failure stops the machine and requires a Machine Home Zero Point Return.
I'm still trying to figure out how to keep the generated leg from falling too far and causing the Power fault.
RPC is 220VAC 15hp. Automatic Capacitor start, with switching relays. Voltage balanced via Caps. All wired with #10 wire, and 50AMP breaker.
How much of a load will an idle motor place on a VFD? I didn't think it would be much once the motor was spooled up to speed. I was under the impression that the output waveform of a VFD was not pure sine, but either clipped or almost square. Was hoping the the idler motor would only be used to smooth out the wave form, not load up the VDF.
Would a 10hpp VFD adequatly power a 8KVA machine??? The VFD I am looking at is rated. 7.5kW, 13.3 kVA, 32A
Regards,
Heli  |