DoAll MP-20 Transformer

That Square D thingy is the motor starter for the motor. A motor starter consists of 2 parts: 1) the contactor, and 2) the overload relay. Because the machine was apparently running on 460V, the heaters on the overload relay will be wrong, and will need to be replaced with the correct ones for operating on 230V. The heaters are those fuse looking things below the contactor. Your electrician should be able to help you with that.

That transformer has seen better days, time to remove it and sell it for the scrap copper. Replace it with a 250VA standard control transformer.

This will give you enough transformer capacity to provide the 120V control voltage and enough reserve to power a 100W lamp. Although I would install a LED lamp or maybe even a couple of them.

It looks like you need to replace all of the wiring, it looks a bit mouse chewed.
 
JimDawson said:
That Square D thingy is the motor starter for the motor. A motor starter consists of 2 parts: 1) the contactor, and 2) the overload relay. Because the machine was apparently running on 460V, the heaters on the overload relay will be wrong, and will need to be replaced with the correct ones for operating on 230V. The heaters are those fuse looking things below the contactor. Your electrician should be able to help you with that.

That transformer has seen better days, time to remove it and sell it for the scrap copper. Replace it with a 250VA standard control transformer.

This will give you enough transformer capacity to provide the 120V control voltage and enough reserve to power a 100W lamp. Although I would install a LED lamp or maybe even a couple of them.

It looks like you need to replace all of the wiring, it looks a bit mouse chewed.
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Hello,

Thank you very much for the information. Do I have the heaters circled in the pic? They need to be changed even though the starter says it is rated for 7.5hp at 230V? The electrician I have knows wiring but outside of that I'm not sure. He seemed pretty confused on how to wire up the 20hp idler motor for the phase converter. I think he mainly sets up panels and outlets and doesn't wire up much equipment. I was thinking I would need to partially disassemble the machine so I could check all the wiring and make sure everything is in good condition. Figured I would paint it while I have it apart as well. Should be a nice looking and operating saw once I'm done. For the price I paid I figured I would need to put some work into it. Thank you very much for all your help,

TwinDad
 

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TwinDad said:
Hello,

Thank you very much for the information. Do I have the heaters circled in the pic? They need to be changed even though the starter says it is rated for 7.5hp at 230V?
Click to expand...
My pleasure. Yes, you have the heaters circled. The heater size is based on the motor nameplate current draw at a given voltage. So a motor wired for 460V will draw 1/2 the current of the same motor wired for 230V. If you can remove one of those heaters, there should be a number on the back of it, or maybe you can see a number on the front. That would help identify exactly which series of heater those are. Worst case you can install a new motor starter with an adjustable overload relay.


TwinDad said:
The electrician I have knows wiring but outside of that I'm not sure. He seemed pretty confused on how to wire up the 20hp idler motor for the phase converter. I think he mainly sets up panels and outlets and doesn't wire up much equipment.
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Many times electricians don't have knowledge of wiring industrial equipment unless they have worked in that environment. Many spend their entire career wiring houses.

TwinDad said:
I was thinking I would need to partially disassemble the machine so I could check all the wiring and make sure everything is in good condition. Figured I would paint it while I have it apart as well. Should be a nice looking and operating saw once I'm done. For the price I paid I figured I would need to put some work into it. Thank you very much for all your help,

TwinDad
Click to expand...
Good plan. Based on what I could see in the pictures, all of the wiring is suspect.
 
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Since your going to use three phase keep that contactor and buy heaters, the number is by the screw head on the heater.
This would be a great first electrical panel to build.
Basic control circuit with some fuses/circuit breakers....you will understand more about your machine!
A good used transformer that size can sometimes be found in HVAC or dust collection equipment.
 
Jim Dawson gave good advice. If you need parts Automation Direct is very good. Control wiring is very simple. You should be able to find diagrams on line. Typical house electricians don't have to know anything about 3 phase industrial wiring. I just watched a licensed electrician take 3 hours to figure out that the timer relay on a Y start Delta run control wasn't switching to Delta and was the reason the motor wasn't developing full power.
 
Hello,

So I don't need a 3 phase to single phase transformer? I can just take two legs out of the 3 and run them to my transformer and than it will drop the voltage from 240 single phase to 120 single phase? Is that correct or am I way off base here. I know enough about electricity to know that I don't know very much and I'm definitely not one of the people who is afraid to ask questions or say I have no idea. I really appreciate all of your help everyone.

TwinDad
 
TwinDad said:
Hello,

So I don't need a 3 phase to single phase transformer? I can just take two legs out of the 3 and run them to my transformer and than it will drop the voltage from 240 single phase to 120 single phase? Is that correct or am I way off base here. I know enough about electricity to know that I don't know very much and I'm definitely not one of the people who is afraid to ask questions or say I have no idea. I really appreciate all of your help everyone.

TwinDad
Click to expand...
Yup, that's correct.
 
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