220 electrical help needed

we got the lift installed yesterday! the installers were doing it as a side job so the electrical was left up to us to be done.
It is a 220 system with 4 wires. Not a problem really, 1 neutral, 2 hot, 1 ground. Ran the ground to the conduit.
there is a C-20E magnetic contactor in the electrical box on the lift. wires are marked R,S,T on the input side of it.Output side looks all factory wired to me. How do I know which 2 get the hot wires and which one gets the neutral?

I am not sure what the markings mean,but the neutral should not be broken by the contactor at any time. I am surprised it even has a neutral to be honest with you. My thought is that the lift should be straight single phase 220v,unless they require some 120v power for controls or something.

I take it you don't have a wiring diagram and none is available online? See if you can find some docs on the contactor.

I would run the ground wire separately, not as part of the conduit, but that's just my amateur electrician opinion. As is this: Get out your ohm meter, set at the lowest scale, and start measuring the resistance between the 3 wires on the motor side. I'm GUESSING that between the 2 hot leads you will find one reading and between each hot lead and the neutral you will find another, which will be the same.

Hess is right. Run the ground separate- conduit is not good enough.

Ah, that ain't no mere 220 unit, that's a three phase setup.

R S & T are hot

The fourth wire is the ground wire.

This setup will NOT work with your residential type 220 wiring. You have to either rewire the motors, or the house/shop.

Some times a three phase contactor is used for a single phase motor, so all may not be lost...what does the name plate on the motor say? If you can, post a photo of the contactor wiring.

internetautomart wrote: we got the lift installed yesterday! the installers didn't know how to wire a three phase motor to my existing single phase electrical panelso the electrical was left up to us to be done. It is a 220 system with 4 wires. Not a problem really, 1 neutral, 2 hot, 1 ground. Ran the ground to the conduit. there is a C-20E magnetic contactor in the electrical box on the lift. wires are marked R,S,T on the input side of it.Output side looks all factory wired to me. How do I know which 2 get the hot wires and which one gets the neutral?

Fixed it for you. There are phase converters that can make 3 phase out of single phase.

The ground inside the box was just running to the box also, that is why I just ran it to the conduit.
Motor: Contactor

if it needs 3 phase, I'm 90% sure there is 3 phase here. this place used to be a manufacturing place. we have some serious electricity here

If your shop has 440 volt three phase and you don't know what you are doing it can kill you very dead very quickly. 440 volts will reach out for you under certain conditions , similar to an arc welder. proceed with extreme caution or not at all. Hire a pro if you have any doubts,you may not get a second chance.

He means 480 volts,and he is right it is nasty stuff. Chances are you won't get hit by the full 480,but even one hot leg to ground is 277 volts,and it hurts like hell,ask me how I know. More likely you have 208volt three phase,but even still be careful.

TRoglodyte wrote: If your shop has 440 volt three phase and you don't know what you are doing it can kill you very dead very quickly. 440 volts will reach out for you under certain conditions , similar to an arc welder. proceed with extreme caution or not at all. Hire a pro if you have any doubts,you may not get a second chance.

THIS^^^ DO NOT SAVE MONEY HERE!!! I watched someone who KNEW what they were doing get killed by 440 three phase. This guy was a licensed, union electrician with 30 year's experience. He left three kids and his wife behind. Not something you want to witness let alone do yourself. Please don't mess with this.

Is the motor wired for low voltage 3 phase(230) or high voltage (480) . This will matter also.

I hate to be rude, but we've been down this path too many times on this board:

If you're asking about 220V wiring questions on a internet forum, HIRE A berkeleying ELECTRICIAN.

440 will definitely knock the crap out of you so whatever you do be careful. Without a wiring diagram I wouldn't want to wire it. The contact looks to be wired three phase but they could be using one section to energize something else. I can't tell with a picture. The motor tag looks to be three phase too, but I can't see the entire tag. What voltage is the motor wired for? What voltages can it be wired for. What voltage is your panel wired for. Without answers to these questions you stand a pretty good chance of blowing something up. Another thing, do you have a rotation meter. Three phase wired wrong will spin motors backwards. That can be hard on a hydraulic system.

This is probably one instance that a pro would be money well spent. If you were closer I'd come look at it, but Chicago is a long haul from SC.

I guess I am going to try to get my neighbor to swing by and check it out a bit. at least the contactor part, they are HVAC and I KNOW that the contactor is used in industrial HVAC so they might have a clue. Wish I had the spare money to just go out and hire an electrician.
FWIW, when we are doing the wiring we have the fuses pulled from the fuse board and we don't pull them or put them back in without throwing the MAIN switch.

Good choice . How much is dead worth?

internetautomart wrote: I guess I am going to try to get my neighbor to swing by and check it out a bit. at least the contactor part, they are HVAC and I KNOW that the contactor is used in industrial HVAC so they might have a clue. Wish I had the spare money to just go out and hire an electrician. FWIW, when we are doing the wiring we have the fuses pulled from the fuse board and we don't pull them or put them back in without throwing the MAIN switch.

Not good enough. Even with the main off, there is power in the panel.

Frankly, if you don't know whether or not you've got 3 phase, you have NO business EVER opening that panel box.

Period.

no voltage shows up on the detector when the main is thrown. to be clear the main I am referring to is a big a.s.s switch on a separate box from the fuse panel. calling it a switch is like calling a B16 motor a big block.

Commercial service probably has a disconnect separate from the panel. That's a good thing. If the A/C guys are used to doing commercial work they can probably help.

I'm glad to hear you've got a separate disconnect.

I still stand by what I said, even if it makes me a Bob Costas.

If you don't know enough about electricity to know whether or not you've got 3 phase, you have NO business EVER opening that panel box.

Period.

Same goes for if you don't know the difference between a switch and a disconnect, or the difference between a fuse and a breaker.

PLEASE DON'T DO YOUR OWN WIRING.

I don't have breakers, I have fuses. It is a switch, albeit a large one. You flip it to turn power on or off. A disconnect is what you pull to cut power, I used one when we installed the HVAC unit for the office (also 220 and wiring done ourselves). I am aware of the differences. I am much more careful with wiring than many electricians I have seen working.

I'm sure you are careful, and I am not trying to insult you. But you are not able to identify whether or not you have 3 phase, and it should be very simple with nothing more than a glance at the panel labeling or the number of line lugs or buses.

While I'm certain that you believe you are careful, you do not understand what you are working with. Your "carefulness" will not help you if you manage to energize that conduit, or create an arc flash.

With all due respect, if you are unable to identify the phasing of the system and you open the panel, you are NOT being careful. You are being foolish.

You are working during the winter, when there is the greatest potential for static and arc, in a garage which may have gasoline or other volatile vapors, with a system of an unknown voltage, phase, and amperage.

Go ahead and call me a Bob Costas, or rant against my insulting you. But DON'T SCREW WITH THIS WIRING.

I have a lift that I think is similar to yours by looking at your pictures, it is three phase. Wiring a three phase motor requires a special skill set that you don't have. Careful isn't good enough in this case.Even if you manage to power this unit and it is not properly fused and grounded it could kill anyone that touches it were there a short in the motor at some point in the future.I am not trying to be harsh, just reiterating the good advice others have offered in this thread. Wait till you have the money to do it properly. Please.

I guess in one of my posting edits I forgot to leave in that I am pretty sure the motor is 3 phase based on color coding inside the box.

I need to find a phase converter now or possibly get a 3 phase line run in here for it. I'll call the electrical co in a bit.

I have to screw with the wiring, how else will I learn? I ask questions to learn. (reverse that order though )