Motor wiring help

T

tattooedfreak

Steel mutilater is more like it.
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Mar 12, 2010
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Help.... I have recently set up my new (to me) Coote and I am running it on the motor that came with it. It is a 1/2 hp 110 (I believe) motor. I don't run it long or hard as I don't want to blow the motor. I do want to upgrade to a 3/4 or 1 hp motor as soon as I can afford one but my issue is with wiring. I can wire just about anything if I have diagrams and instructions but I don't really understand the 110/220 v, 3 phase variable stuff.. it's all just words to me. How do I know if I have enough power running to my shop and outlets to let me run a larger motor. I am currently running 100 amp service to my house and my shop is on a circuit with another room (yes I will be giving it its own circuit soon, is 30 amp enough?). Can someone explain (with crayon drawings if neccessary) please? Thanks

Sean
 
The individual breakers in the service panel should be labeled for their amp rating. About 80% of this rating is all you want to pull at the device. I could be wrong but I believe typical residential in the US is usually single phase.
Edit: I see that you are not in the US, my last comment is irrelevant.
 
Yes, but I have 2 spare places in my panel that I can switch my shop power to. I want to make sure I have enough power to it so I can run more than just my lights. It is currently on a 20 amp circuit with another room in the house and i would like to have it on its own breaker. Canadian electrical standards are the same as US or close enough to be the same.
 
Anything shy of about 1.5HP will run happily on a standard 15A 110V duplex type outlet.

For a grinder, I would recommend a 20A 110V circuit that you just use for the grinder, not connected to the lights.

My actual recommendation would be this, since you only have 2 available slots, skip 220V unless you absolutely need it, should you decided you do the wiring will be the same just a new breaker and new outlets for 220V.

Run 2 20A circuits, one should feed lights and 1 outlet, the other should feed a second outlet.

At 20A you'll have enough power for up to a 2HP compressor on one circuit branch, and a grinder/lights/other tools on the other. In a one man shop you shouldn't have too much to worry about with overloading a circuit with multiple machines.

As for 3PH and a VFD that has nothing to do with your house wiring as you won't be getting more than 1PH service.

A VFD such as the one I have takes your 110V (in my case, they make a range) and converts it through circuits to 3PH power, it also allows you to control the speed of the motor by adjusting what the motor sees. It is a 2 part system. a 3phase motor and a VFD that takes single phase input and 3 phase output.

On ebay I managed to score a 1HP VFD and a 3/4HP Baldor motor both new for $250 which run happily on any 15A or 20A circuit in the house or garage.

PM if you want the info for the sellers.

If you'll be happy with 1HP you shouldn't have anything to worry about in terms of power. You can either run a 1HP 110V or 220V motor off a 15A 110V or 20A 220V (which gives you tons of headroom)
 
Ok, so when I see 110v 15 amp 220v 7 amp on a motor, it doesnt matter what I plug it in to (power permitting of course) as much as how it is wired?
 
Yep,

The only thing that matters is the motor is wired according to the diagram for the voltage you are feeding it.

Those are just ratings so you know what size circuit to put it on at different voltages.

The motor should be happy to run on either.
 
Excellent, thank you very much. I don't think I need much more than 1hp, I just don't want to bog down my grinder and then burn out a motor. I just picked up a Coote and I found that when grinding flat on the platten, it would slow everything down and I would have to pull back and let it all speed back up again.
 
As an after thought, could I run a sub panel in my shop or would that defeat the purpose? And does a 220v motor have a different wire run than a 110 or is that just for dryers?
 
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For 220V you'll have roughly half the current so you will be able to use a lower gauge wire, but keep in mind you wire to the breaker not the load. So if you have a 7A load but a 15A breaker you need to wire for 15A. Motors don't require the 4th wire neutral that some dryers do. They use simply the 2 hot legs for 220V and have no use for 110V when run at 220V.

If you can run a subpanel in the shop that's a great idea. Just take 20-40A 220V with neutral into the shop for a subpanel, then pull your 110V off that for lights maybe even give yourself a 110V/220V outlet.
 
I have a 1 hp 1725 rpm on my Coote and it churns along happily as long as I don't really lean on it. It is running around 2500sfpm if I recall the math correctly. This is a little slow compared to most single speed grinders but is great for grinding after HT.
 
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