[neurofen]

I've just wired up my spindle and VFD. All seems well but the spindle current readout on the vfd seems way off for the spindle rating.

I'm going to speak to the techs monday on the phone but in the mean time scratching my head. I've ordered a spindle mount which doesn't arrive until Tuesday so I can't mount the thing and monitor the current draw when under load and don't have a tachometer so cant check if the rpm's are correct for the freq.

The voltage rises and falls correctly when accelerating and de-accelerating. between 0 and 220v. VFD is in constant torque control mode.

The spindle is rated at 1.5kw, 8 amp, 220v (ebay chinese air cooled jobbie)

VFD is a moeller DV51.

The VFD is showing a current draw(from the spindle) of around 0.7amps when operating anywhere between 133-400Hz, and peaks slightly to around 1.7Amps when linearly de-accelerating to 0, at around the 50-100Hz mark.

Any ideas why the spindle is drawing so little is this normal?

[tahustvedt]

The spindle only draws what it needs, depending on the load. With no load the current should be very low. While milling it will be higher, probably a couple amps normally. 8 amps is the maximum it can handle continously, and it takes a lot to reach 8 A. That's a substantial load on the machine.

[neurofen]

thanks tahustvedt, I was hoping that was the case.

[dan_barber]

You can use a power monitor. SymCom's Model 777-P2 series has great features. It's a little expensive and probably overkill in your case.

SymCom Power Monitors & Overload Relays Distributors