Tapping a 220V dryer outlet for a spindle

Finally broke down and ordered a Mafell Quick Change Spindle:


and the recommended step-up/down transformer:

and am wondering if rather than running a separate circuit (if it proves too much for the existing basement wiring) I shouldn’t just tap the dryer outlet which is on the other side of the wall — if I get a splitter:


and a 220V-110V adapter:


I’d essentially have a dedicated circuit (so long as no one is doing laundry) — even w/ adding an extension cord it seems a lot cheaper than having an electrician do a run from the panel — is there anything I’m missing here?


Will, When I had my house built 8years ago, I added 2x 220v circuits in the garage (they ran 30A dryer plugs)

With no firm plans as to what they were for, or where they should go, so I just had them put on the easiest wall. When I needed to get 220v power across the shop without running a cord every time, it was time to do some semi permanent wiring. I bought a subpanel, and a 6ft dryer cord, 4 breakers and ran 12ga extension cords out of the panel with the appropriate plug ends on them. In this, I ran 2-220v 20A circuits, and 2-110v 20A circuits, knowing full well that at any time my concurrent current consumption would not come close to exceeding the capacity. All told, it cost me under $200, as I got to use up obnoxious 100ft extension cords

If I ever have to reconfigure wiring or plug ends, I unplug the whole shebang, no more guessing with a screwdriver if I got the right breaker!!

When I move from this house, I take my garage wiring with me.

I also have the in wall circuits to pull off, so I’ve got a few options for power. It has worked out excellent.


EUro 220V and US 220V aren’t the same

Euro 220V is a single sine wave against neutral with an RMS of 220V. (three phase is 3 sines at 120 degrees phase differential, with an RMS of 380V), at 50Hz

US 220V is two separate sine waves, each 110V against neutral, at 60Hz

it might be end up ok, if theres s rectifier and voltage regulator and chopper in the electronics… it’ll eat just about anything with enough oompf.

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Yeah, the step-up/down transformer I got is specific to converting to/from European voltages, and is the exact model/purchase link recommended. At 48 lbs., it’s hefty enough to have all that and more (and is fused, which I’m glad of).

Tapping the dryer plug for 110 is a fall-back position if I find I’m overloading the basement circuits (not convinced they’re up to code — I’d like nothing so much as to gut the entire basement, properly waterproof it, replace the oil furnace w/ a pellet stove and redo the layout, but that’s not in the budget). Using the dryer plug is a matter of letting sleeping dogs lie and not opening a potential can of worms.

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Just make sure you know the code for those extensions…you don’t want heat building up in the wires that can cause a failure (or fire) a few years from now. You need the right gauge for the amperage and also consider the distance. The last thing you want is to find out your insurance isn’t going to cover a fire because you did your own “semi-permanent” wiring short of code.

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https://www.abt.com/product/135478/Miele-Laundry-NEMA-Adapter-10983750.html is a thing :wink:

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Yeah, that’s why I’m going for the more expensive versions which are UL-listed/tested (and will do the same for a suitable extension cord — I’ve got a heavy 10 AW gauge one I can repurpose if need be).

US 220V “is a single sine wave” between the hot pairs also called “single phase”. The neutral carries no current from the equipment use.

Hey, @WillAdams why do you need the transformer? The control electronics?

The tool in question is a European one which wants 220V as used in Europe. The transformer will take in 110V and provide 220V for it.

Using a transformer seems like a terribly inefficient method. Especially since you have “220V” available. That spindle is around 100VA by specs. I’d think your dryer connection wouldn’t even notice it.

Another thing about transformers … is yours made with primary and secondary isolated or is it wound as an autoformer where one input wire goes all the way to the output? That website doesn’t specify that.

Yes, but the 220V is two-pole, while the small European power tool wants only one — I’m hoping it won’t be necessary — this is a fall-back position.

I guess the question then becomes:

What is the best way to power a 220V European tool in the U.S.?

As noted, the transformer is the one recommended, but I suspect that it is suggested in the context of powering a tool on a job site and that it be up to the rigors of knocking around in a truck and on a job site (which I’m fine with — I bought it) — it does raise the concern of EMI.

Well, what are you powering: the spindle or the power supply? Cant’ be both.

US “220V” single phase is two wires (without the neutral.) EU “220V” single phase is two wires (involving the neutral.)

I’m assuming EU has a safety ground, as the US does, that doesn’t involve the neutral.

Perhaps use an isolation transformer (not step-up or step-down) if you’re really concerned (for some reason unknown to me.)

If you’re powering a power supply, then there’s already an isolation transformer in there for the control electronics.

I’m powering a small power tool:

which will be used as a spindle.

Per the owner’s manual it seems to have a 2-prong outlet (presumably it’s double-insulated):

Apparenty I should have also bought:

Ok. I got it. You’re not building one of those “high tech” spindle controllers.

In my case, I would cut that EU plug off and wire on a standard US “220V” plug, add a standard “220V” receptacle nearby and add your appropriate ESTOP hardware.

I would wire that dryer connection in “somehow” and lockout the dryer while you are using the spindle.

Yes, I’ve simplified that process, but I’m in Texas and at lease 1000 miles away. :smiley:

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Further complicating this is that I want to plug in through the BitRunner (assuming it will work when then transformer is plugged in — not sure if it has a draw or no, guess I should check) which is in turn plugged into my Festool CT Midi — a direct 220V plugging in is not an option (I’d be plugging the Festool CT Midi into the 110V tap from the dryer).

But here’s the problem.

You’ve linked to a spindle that is 230V / 50HZ. Perhaps you weren’t being specific. They have one in the list that is 120V / 60HZ, but that’s the only one I see. You may not be able to use a 50HZ spindle on the 60HZ power if they have a built in speed controller; depends on the manufacturer’s design.

Perhaps I wasn’t clear on the reason for the step-down transformer. Perhaps the transformer was to be used with the 120V / 60HZ model spindle; stepping down from the “220V” dryer connection. Can you tell I’m confused? :smiley:

As I noted, I’m buying the step-up/down transformer which was recommended — the difference between 50Hz to 60Hz should just result in the unit running 20% faster, right?

So instead of 4,000–25,000 RPM I’ll have 4,800–30,000 — so long as I avoid the highest speeds everything should stay w/in expectations, right?

I can’t tell you that, because I don’t know what kind of speed controller they are using in that spindle. The manual doesn’t seem to specify that.

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