[amowry]

I just ordered a Delta VFD022M21A VFD to power a 2.2kw spindle, and I was surprised to see in the manual that it draws 28 amps (240v single phase). Does that seem high since it is only powering a 10 AMP spindle? Do I really need a 30 AMP circuit for this?

[CNCMAN172]

You must have the wrong manual. If you google that VFD it pulls 10A at 240 volts please see their link.
Russ


https://www.automatedpt.com/delta-vfd022m21a/

[ger21]

Russ, the manual says 27A input/ 10A output.

That 27A would be worst case, with a 10A spindle at full load.
Most 2.2Kw spindles are 8-8.5 amps, and you'll likely never run it at full load, so you can probably get away with a 20A circuit.
But if you plan on pushing it really hard, you may need the 30 amp circuit.
Fwiw, my 2.2Kw spindle under no load draws less than 1 amp, according to the display on my HuanYang VFD.

[amowry]

Okay, thanks! Is it the 1ph to 3 ph conversion that accoints for the huge difference in input and output current?

[ger21]

Yes.

[mactec54]

You must have the wrong manual. If you google that VFD it pulls 10A at 240 volts please see their link.
Russ


https://www.automatedpt.com/delta-vfd022m21a/

With the link you posted Delta recommends 27A in 10A out for that VFD, a lot don't take any notice of what is normally recommended and down the road they fail

A single phase powered VFD needs a lot more input current available, than the same drive with a 3PH input supply

I always recommend no less than a 25A Breaker circuit for the supply to any machine that is using single phase, can you use less, it will depend on how hard you drive your spindle

2.2Kw spindle can easily draw the max output amps of this VFD

Spindle rated voltage (220v) 2.2Kw / 220v =10A

[amowry]

Okay, thanks! I’ll just go with 30 amps to be safe. There seems to be a lot of erroneous information online where people assume that only 10 amps single phase is needed to power these 2.2 kw spindles.