440 to 220 Rewiring

[h13man]

I'm need of a electrical maintenance guru.  I'm troubleshooting my Hardings 618 surface grinder for starting issue and found I have 120v and 170v input into the transformer, 109v on the jumper wire, and 53 v output to the start button. I assuming that 53v isn't enough to start the circuit. I can manually override the magnetic switch and it runs. Any input on the this issue would be appreciated. Everything at the motor is changed as per schematic and heaters are reorientated to panel instruction to this point. I'm assuming the transformer need to be reversed to step up from its present step down output. Is this possible?

[f6john]

You lost me at 440.

[_Sheffjs_]

Yes the building I take care of has 120 or some say 110 it has 208, 240 Or some say 220 it has 277 (lights) and 480.  These voltages are a mystery to me. 

[scooperhsd]

Get an electrician familar with commercial buildings and service to them.

[da prez]

  220 voltage in the U.S.. is two 120 lines. Check voltage input. They should be the same. The voltage drop to the switch seems high. It is furnished thru a transformer. It is usually low voltage to prevent wetting your pants.
 Start with input. Check transformer input and output. There is usually a wiring diagram on the machine. To have a 220v input should give you a 440v run. Is there a voltage converter(?) used.
  It is enough voltage to curl your hair. GET help.

                                             da prez

[mrtlc]

If your trying to hook 240 single phase to a motor that is wired for 440 three phase, I don't think you can do that unless you get a single to 3 phase converter. There is a way to make a converter out of a three phase motor. Good Luck

[Jess Tolbirt]

120 plus 120 = 208  117 plus 117 = 240   277 plus 277 = 480
now that said if the unit you are trying to start has a starting control circuit you have to know the coil voltage that is required to pull in the contactor. it will need a step down transformer to match that voltage for the control circuit. if the control fuse blows you can get a backfed voltage of about half of the transformer output, depending on how the coil is wound. If you dont know anything about controls then it would be best to hire an electrician to sort it out.
here is a diagram of a simple control circuit using a transformer for control voltage.
Ans some that dont require a transformer.
https://www.google.com/imgres?imgurl=https%3A%2F%2Fsub.allaboutcircuits.com%2Fimages%2Fquiz%2F03896x01.png&imgrefurl=https%3A%2F%2Fwww.allaboutcircuits.com%2Fworksheets%2Fac-motor-control-circuits%2F&tbnid=_NM6MqDpgTbmPM&vet=12ahUKEwjFwJz8x8vtAhVOXawKHX7EC38QMygFegUIARCvAQ..i&docid=egfWxN1I0CmgoM&w=300&h=224&q=diagram%20of%20control%20circuit&client=firefox-b-1-d&ved=2ahUKEwjFwJz8x8vtAhVOXawKHX7EC38QMygFegUIARCvAQ

[DIGGER]

Sounds like you need to hire a qualified electrician to do your hookup.    You send the wrong voltages to the wrong places and you can do major damage to your machine

[OnaWingandaPrayer]

110/220-120/240 are single phase standard household voltage.

120/208 is a three phase voltage...each phase to neutral is 120, phase to phase is 208.

277/480 is also three phase...277 each phase to neutral, phase to phase is 480.

I cant help you sort out the problem you have. I would as mentioned by others, get a qualified electrician if you are not familiar with this .

Be cautious, especially the 3 phase, can be fatal to contact.

[Robert]

The magnetic switches are known to go bad, the fact that you can push the switch and everything runs probably means you dont have a power issue. The voltage to the magnetic switch sounds about right. Replace the switch or check the wiring to the magnetic switch and you will probably be fine. Sometimes they do have a fuse or the contactors in the switches go bad. Sometimes you can disassemble it and clean the contacts and get it working. They are not usually expensive and fairly easy to replace but shut off the power before you do anything.

[The emperor has no clothes]

The magnetic switches are known to go bad, the fact that you can push the switch and everything runs probably means you dont have a power issue. The voltage to the magnetic switch sounds about right. Replace the switch or check the wiring to the magnetic switch and you will probably be fine. Sometimes they do have a fuse or the contactors in the switches go bad. Sometimes you can disassemble it and clean the contacts and get it working. They are not usually expensive and fairly easy to replace but shut off the power before you do anything.

I would disconnect it completely from power before starting.

[h13man]

The magnetic switches are known to go bad, the fact that you can push the switch and everything runs probably means you dont have a power issue. The voltage to the magnetic switch sounds about right. Replace the switch or check the wiring to the magnetic switch and you will probably be fine. Sometimes they do have a fuse or the contactors in the switches go bad. Sometimes you can disassemble it and clean the contacts and get it working. They are not usually expensive and fairly easy to replace but shut off the power before you do anything.

The transformer is a onboard unit in the power box not a building unit. It was setup for 440V 3 phase but now I'm using 220V 3 phase and all info was supplied on the machine for rewiring the motor and heaters etc. Never had an issue with my Bridgeport mill or my Takisawa lathe running 220v though not knowing if they were SU for 220V or 440V or if they had magnetic starters etc. as both were 80's vintage compared to this 61' vintage machine. Basically I'm wanting know if the transformer can reversed to a step application if higher voltage is needed to supply the current needed to trigger the starter and/or the 53V is the correct voltage for it to activate the starter. I asked here as there are a lot of older gents like myself that might be "fluent" with older machines. 

So I just went and checked the start switch voltage rating and it was 60v! This leads me to believe the starter itself needs to be inspected, rebuilt, or replaced.

I thank everybody for responding as I've hadn't had any responses on the Practical Machinist forum in 2 mos. of waiting.

[Robert]

Is this old enough, 3 phase 220 replaced the magnetic side of this a few times and 50 volts is about right. I had that voltage to it even when this piece of equipment would not work. Turned out to be the magnetic portion and the switch replaced it and then it worked. The wiring diagram should be on the inside of the unit.

When I closed the contacts manually it would work but when I wanted it to work automatically it did not.

Its almost new btw  

[h13man]

Age wise, no but mine is Cutler-Hammer Nema size 1. I think I'm on right track as Robert and you pretty much summed the proper voltage for the start circuit. Thank you so much to the both of you.