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Steve G.
Steve G., Electrical Engineer
Category: Electrical
Satisfied Customers: 17726
Experience:  Spent 20 years as an Electrical Engineer, designing electrical plans and specifications.
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I have a 3 phase panel 208y/120 volts, 4 wire. I have a 3 phase

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I have a 3 phase panel 208y/120 volts, 4 wire. I have a 3 phase motor 220/380 volts. I believe the factory wiring is for 220 volts. Is the motor compatible with the panel? Can I run it by wiring 3 hots from a 3 pole breaker to the motor and keep the default factory wiring of 220?

Hello there and welcome to Just Answer. My name is XXXXX XXXXX I will be assisting you today. I am an engineer with over 30 years of electrical and electronic training, repair and installation experience. I will try and answer your question accurately and precisely so that we can get you on your way.

The motor will run on 208V. It will lose a little torque. It will draw slightly more than the rated nameplate current.

You would use a three pole breaker and run your wiring to your starter/contactor.

Please let me know if I can help you further.


Customer: replied 3 years ago.

Thank you Steve, so basically the max power supplied by this kind of panel will be 208V whether I'm hooking up a single phase 220V motor or the 3 phase 220/380V motor? This kind of panel is a standard and so are 220V motors. In this scenario the kind of torque loss you mention is a pretty common condition?


The max voltage the panel will provide is 208V per phase.

A single phase 220V single phase motor or a 220V 3 pase motor will work fine on 208V with the caveats previously mentioned.

Can you give me the nameplate data off that motor?

Are you sure it has 220V three phase connections because on a 380V three phase system, 220V would be the line to neutral voltage.

Do you see the nameplate? Let me know what is on it please.



Customer: replied 3 years ago.

I don't have the name plate in front of me but from memory it's labeled 220/380V, 60Hz, 4Kw, Type B and has the delta/wye symbols. The motor is on a woodworking machine, the vendor typically sells motors for European use but I requested a better configuration for the U.S. This is the closest type they had available.

Ahh, this is something different. You may not be able to use it but I would still like to see the nameplate.

This motor is designed for a 380V three phase system. If connected in delta, you would need 380V. If you connect to wye, which some motors can do, the electrical system you would wire that to would be 380/220 where 220 = 380 divided by root 3.

So, botXXXXX XXXXXne is that this is not a 220V motor. It is most likely a 380V motor. That will not play nice on your 208V service unfortunately. There is a good chance that it is also a 50Hz motor in which case running it on 60Hz is going to make it run 20% faster and possibly heat it up a bit in the process.

If you can get me full details of the motor nameplate I will confirm this but it looks as if you are going to need a small step up transformer (for the voltage) and a small variable frequency drive (for the frequency and speed control).



Customer: replied 3 years ago.

Thank you very much Steve, I will get a picture of the name plate for you tomorrow. The one thing I'm 100% positive about is it that the frequency is 60Hz as per U.S. standards.

Ok, then the motor will run at the proper speed.

I'll be here.


Customer: replied 3 years ago.

Hi Steve, took a while but managed to upload the motor plates for 3 machines. I thought they were all identical aside from Kw but looks like there may be some variation? Also including a picture of one of the starters and have been told that this type of motor configuration is used in Mexico.




Sorry this has become more involved, be happy to pay more and thanks in advance.

Ok, I took a look. I'm going to say that I think you are ok at 220V. The planer and jointer are definitely good. The table saw - I found a couple of manufacturers that make that motor and it clearly runs at either 220 or 380.

You can't hurt it by hooking it to 220 just to see if it runs. I think it will run with no problem. The worst thing that can happen is that you have no torque. You wont burn it up.

I think you are good for all three motors.

Let me know if I can help you further.

Steve G. and other Electrical Specialists are ready to help you
Customer: replied 3 years ago.

Thank you very much Steve, I have enough to go on now.

Great, please do not forget to rate my service. I'll still be here if you need more help with this issue down the road.



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