How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Mike G. Your Own Question
Mike G.
Mike G., Master Electrician
Category: Electrical
Satisfied Customers: 7652
Experience:  Proven Professional 48 years Experience
Type Your Electrical Question Here...
Mike G. is online now
A new question is answered every 9 seconds

I have a 3 phase 212 power running to a machine with a 50 mz

Customer Question

I have a 3 phase 212 power running to a machine with a 50 mz 220 motor. I've never had problems TJ jnh motors like this before, but the service tech for the company says I MUST have 220 volts for this Chinese motor because it doesn't have the tolerances of most motors. He recommends that I put a step up transformer on only two lines. Don't I need it on all three lines.
Submitted: 10 months ago.
Category: Electrical
Expert:  Mike G. replied 10 months ago.

Hi, I'm Mike and I'll be assisting you. Please stand by while I review your question.

Expert:  Mike G. replied 10 months ago.

Only 2 boost transformers are required. To select and see how to wire go to Hammond Power Solutions online PDF

Customer: replied 10 months ago.
even though all lines are 212 I only need to boost 2 of them? The wood shop next door has all of their machines connected via 3 boosters. Why would they do this?
Expert:  Mike G. replied 10 months ago.

All I can say is that you only need 2. Why others have 3, I can't say. Go to the PDF suggested for the info.

Expert:  Mike G. replied 10 months ago.

One more thing. I would think that the motor being 50hz and our electric being 60hz would cause a problem.

Customer: replied 10 months ago.
The tech said by boosting to 230-240 that it would make up for it…
Customer: replied 10 months ago.
The motor runs a hydraulic pump. FYI, I know that on several on an old French motors 50mz (c1960s) that also run pumps, they run fine on 60mz even though the motors do NOT say 50/60mz.
Expert:  Mike G. replied 10 months ago.

Only wanted to bring it to your attention.

Expert:  Mike G. replied 10 months ago.

Might want to check out "" for a take on motor burn out with use of different Hz.

Customer: replied 10 months ago.
I appreciate it. The electronics on the machine run into two large inverters and then into mostly DC relays. i will take a look at the smaller motor on the saw and look at the website you provided.So to confirm. 4 pole, 3 phase motor needing 220/240. Choose two of the three 208 main lines running from my disconnect and connect the two step up transformers. The third runs directly into the machine w/out a transformer.
Expert:  Mike G. replied 10 months ago.

The equipment I gave was a buck boost transformer not a single 3 phase transformer. You may use either.

Customer: replied 10 months ago.
Sorry for the delay. Getting in contact with the manufacturer in china and then an engineer that was well spoke in in English was more difficult than expected. I also thought I had responded to you earlier w letttjng you know I was contacting the manufacturer. I can't find a record of that. Sorry for the confusion.Based on the conversation with the engineer he said that due to the "exacting" requirements needed to use the hydraulics pump as a heavy duty "step motor," the small drop in pump pressure by not powering all 3 phases might not permit precise positioning of the table, or the saw and router arms.So I guess my last question to you is, when I wire each phase:
1. Where does the neutral 4th wire go?
2. I need a ground going to each transformer along with on of the phase wires. Correct?
Expert:  Mike G. replied 10 months ago.

The motor will either have designated terminations or wire colors as shown on the wiring diagram