110v spindle with er20

Spindle/VFD (Aftermarket)
1

I know the proper answer is to just suck it up and run 220, but ive been very happily using a chinese 110v 1.5kw spindle for a while now and had no issues with it whatsoever. With a killawatt the most power draw I’ve seen is 9 amps, and that was some heavy duty hogging with a 1.5 inch surfacing bit. I have it hooked to a 30 amp breaker anyway.

I’d really like to have er20 collets. Most of the huanyang spindles with er20 ive seen have been 2.2kw for the 110v units. Can I use a 2.2kw rated spindle with a 1.5kw vfd? Even though I wouldn’t use it much I like the the idea of being able to use a 1/2 inch endmill.

If not ill just suck it up and buy another spindle kit.

2

Hey Echd,

yes, you can run a 2.2 kW spindle with an 1.5 kW VFD. Anyway, the maximum current (in amperes) for the spindle must be set in the VFD. But of course you will not have the full power of the spindle.

3

Thanks for the fast answer. I figured it was fine and I don’t expect these Chinese spindles actually do the ratings they say, but I can’t imagine managing to put 2200w worth of power through without folding my onefinity in half in the first place…

So I’ll go ahead and order one and then I’ll also have my old 1.5 as a spare if anything ever breaks somehow.

4

Hey Echd,

I think since your VFD is already set to the rated current of your present 1.5 kW spindle, and that is probably set at or near the highest value the 1.5 kW VFD will give, your power consumption should not change.

Given your comments, I think you are already aware of the 100 / 200 volts class differences/disadvantages.

Also maybe you know that some chinese spindles sold as 2.2 kW spindles are in fact 1.5 kW spindles (and some sold as 1.5 kW are 1.0 kW in real respectively).

But what matters to you should be the current you set in the VFD which should always correspond to the rated current on the nameplate of the spindle (or less if the VFD is not able to provide the rated current).

5

Yep, sounds about like what i expected.

I should add some 220 outlets and I might at some point, I have easy access to run it now. My reluctance has partly been laziness, partly sticker shock at romex, and partly knowing that it will lead me to spending more on tools when my 110v stuff is perfectly fine. But in my garage / shop I have 3 20A 110 outlets and a 30A outlet so I rarely have issues other than what is probably a failing breaker that will nearly instantly trip on inverter motors for some reason…

If I do swap over the motors to an er20 spindle I didn’t think I would need to reprogram. Honestly I’m slightly reluctant just because it’s not like I could ever hit the insane feed speeds a 1/2 inch bit can pull. But I also want it just because I do.

6

One last question-

Does spindle voltage matter? I am assuming not. If I buy a 2.2k spindle, can I use it when I change to a 220v VFD down the road?

I cannot imagine why this would be a problem given how simple it is to run 110v equipment on 220v. I see voltage written on most of the huanyang spindles, but my assumption is that that’s just because that’s how they are packaged and sold. But I know really nothing of 3 phase power. Could be some of the poles are wound different or something, I don’t know, but my guess is they’re all getting fed the same voltage after the juice leaves the VFD. I always assumed (dangerous I know) that there was a step up transformer in the lower voltage units. If I can just use the same 2.2 spindle down the road I’ll go ahead and upgrade. If I need to also replace the spindle when I change to 220- which I will, one day, I promise, maybe, if I’m not too lazy to get in there and pull the wire- I’ll hold off.

7

Hey Echd,

unless a VFD does not contain a step-up converter, like the Huanyang “B-T” Models or the Invertek Optidrive ODE-3-210058-104#, which are usually much more expensive, generally on VFDs, their voltage output class is the same than their voltage input class.

A VFD works this way: The incoming AC is rectified and stored in large capacitors, and then a microcontroller switches six IGBTs to form three quasi-sine waves out of this DC voltage, each wave shifted by 120° degrees, which results in three-phase current. The frequency of the three-phase current is what controls the speed of a three-phase induction motor. The 50 or 60 Hz frequency at the input of the VFD was rectified, which means it’s gone, and it’s now DC that is stored in the capacitors. The VFD’s microcontroller now takes care to output waves with the needed frequency. Many VFDs have the ability to produce three-phase electricity with frequencies of 0 – 600 Hz. To alter the frequency is necessary because the speed of induction motors is controlled by the frequency of the three-phase current. Note that when measuring and comparing AC voltages, you do never take the peak voltage of an AC wave, but the so-called RMS value.

What delimits the power of a spindle, besides the mechanical load capacity (e.g. bearings), is its heat dissipation because of the power loss. The power loss in induction motors depends on a few different factors, but one is whether the cross-section area of the the copper wires that make up the coils is dimensionated to have a certain (low) impedance to accomodate a certain current before getting too hot. The impedance of a coil, among other factors, depends on the cross-section area of the wires that make up the coil.

A VFD with 110 V AC input will vary the output voltage in a range of up to about 110 V to drive the motor and control the current this way. It will not be able to provide 220 V, regardless of how high currents it can deliver. The maximum current however that could flow depends on the motor coils impedance. The impedance of the spindle may allow you to deliver more current than is rated on its nameplate (which is 8 A for a 220 V 2.2 kW spindle).

In all VFDs, you have to limit the current that goes to the spindle. There are 2.2 kW spindles offered that are for both 230 and 400 V, and when using the first voltage you set 8 A as limit and with the second you set 6 A as the limit, to set them to the same power. But their copper wires that make up the coils are surely dimensionated to allow for the bigger of the two values, which would be 8 A current. I don’t want to guarantee that you will not harm your 2.2 kW 220 V spindle if you set more than 8 A in your 110 V VFD, because usually the spindle manufacturers make the motors for a certain operating conditions.

Anyway it is the frequency of the three-phase output current that controls the speed of the spindle, regardless of voltage or current.

8

Thank you, that resolved several misconceptions I had.

So now I’ll just bite the bullet and pull wire for 220. No point in upgrading twice.

Thank you again.