I have been using my machine for the last 3 years, no big issues (
very long build log here). Lately I got a hold of a 240V Watt meter (like the 120V Kill-A-Watt gadgets) and measured the power consumption of my machine. I have the steppers (three very quick 460 in-oz NEMA34 for x an y and a slow fat 1600 in-oz NEMA34 for z) with Gecko203Vs on an analog 72V/20A supply as well as a Chinese 2.2kW spindle with Hitachi VFD on 240V power.
I was surprised how little power the machine actually needs:
- Idle (spindle off but VFD powered, steppers in stand-still with half current) only 0.76 Amps total. That is only 182 Watts! I guess I have a green machine :wee:
- Spindle on at 13,000 rpm but no load: adds about 0.9 amps
- Machine moving at average 300 ipm in x/y circles - no clear indication, does not change much the load. I suspect at that speed the steppers can't take up more current. May be different at lower speeds.
- Spindle cutting with 1/4" bit and 1/4" deep at 300 ipm in poplar: hard to say (fluctuating) but adds maybe 1 amp or 240 watts
- Spindle cutting with a 3/4" router bit 4mm deep in poplar at 300 ipm: adds only 4-5 amps or 1200 watts.
Just some data for your pleasure. But I know at least my stepper power supply is seriously over-specified and the 2.2kW spindle is more than up to the jobs I normally do.
I did have the spindle bog down occasionally when diving a large bit (say 1.5") into the surface at high speed without ramp. But I never had my 20 amp circuits for the machine trigger the breaker.