I'm getting ready to start wiring install for my new lift. It needs 240 V / 25 amp and I've got my 10-3 romex and 25 amp double breaker. However, I just discovered that the hydraulic pump motor has only a black, white and bare (ground) wires. Does this mean it does not require a neutral wire? I haven't run into this before. I think you have to use a double breaker in order to get 240 V, but how do you get 240 at the motor with only 2 wires? Just use the black and red and cap the white?
240 V electrical
- Thread starter MikeC55
- Start date
djbmw
Well-known member
You should check out the other thread...
Thread 'it's quite common that people to think you need 3 wire plus ground for 240 volts' https://www.garagejournal.com/forum...need-3-wire-plus-ground-for-240-volts.523398/
Its very unusual for a neutral connection at a motor. Cap it off.
Romex shouldnt be run directly/exposed to a motor. Stop at a JB on the nearest wall and transition to a suitable cable/cord/conduit. I'll leave the NEC particulars to others.
Romex shouldnt be run directly/exposed to a motor. Stop at a JB on the nearest wall and transition to a suitable cable/cord/conduit. I'll leave the NEC particulars to others.
can you post a pic or two of the motor? one with the dataplate would be great.
djbmw
Well-known member
You dont.
Just 2 hots and a ground.
But... some devices also use 120v for additional accessories...
Thanks Sherlock...
djbmw
Well-known member
You asked, I answered. You're very welcome
Believe it or not, not everybody knows everything about electricity.
We would not need electricians if everybody knew everything about electricity.
OccupantRJ
Well-known member
240, 241, whatever works?
manwithtools
ALLIANCE MEMBER
Just not 220, never 220...
Pull the manual out and read it. What does the lift require? 240vac or 120/240vac? There is a difference.
I doubt you need 120/240vac. So just run your 10-3 nm-b from panel to lift and cap the neutral. (Worst case, you need it now (unlikely) or in the future and it's ready to go.)
Read the motor nameplate. It probably states 208, 220 or 230vac. It will also tell you how the motor is to be wired or it may only have 2 wires.
I doubt you are actually wiring the motor but rather somewhere upstream that includes start pushbutton, high limit position switch and maybe overloads. This would be the "power connection" to the overall unit.
Post a pic of the wiring diagram and motor leads & nameplate if still uncertain.
wyliesdiesels
Well-known member
a 240v motor doesnt need a neutral because it doesnt use 120v. cap the white. and 240v is only 2 wire plus ground
Snapped-off
Well-known member
It let's you pack a bunch of single pole breakers into a sub panel due to power density requirements/constraints.
What good is a single pole breaker in a 240v circuit?
Snapped-off
Well-known member
You quoted the answer.
Why don't you explain it for all us lesser beings
Snapped-off
Well-known member
If you have 1,000 sub panels, do you want to install an extra 1,000 of them just to accommodate 2 pole breakers, or stick to just 1,000 panels, and load them up with single pole breakers. All loads are 240V.
Wtf are you talking about? Show me a service here in the United States that will provide 240v on a single pole breaker.
I have installed a couple 480v single phase services that would provide that voltage. But that is hardly common and definitely not worth discussing in the context of this thread.
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Snapped-off
Well-known member
415/240 is super common in data centers right here in the US.
You're the one asking what a neutral in a 240 circuit would be for.
Cruzan80
Well-known member
I guess you learn something new every day...
I didn't realize data centers regularly needed or installed hydraulic lifts!
I didn't realize data centers regularly needed or installed hydraulic lifts!
Oh for sure. Lifting all of those stacks of key-punched cards is heavy work. Think office ergonomics for worker safety!I guess you learn something new every day...
I didn't realize data centers regularly needed or installed hydraulic lifts!
It looks like they were expecting 10/2 nm-b cable to power a disconnect. I can't tell if they provided and wired the disconnect or if you are providing it and then connecting to the power unit.
For a 2 conductor nm-b cable, the conductor colors are black and white. The white is re-identified (by you) to indicate it is an ungrounded hot conductor. Any color except green is ok to use. Let's say you made it red. The black and red wire connect to your 2 pole cb. Obviously, the bare grounding conductor is terminated at both ends.
If you have 10-3 nm-b, use the black and red conductors to connect to the cb and disconnect lugs. Cap the white wire at both ends.
Per the diagram, only two wires come out of the motor. Hook them up as shown. If there are more wires from the motor or nameplate shows multiple voltages, then the nameplate is needed.
Does the power unit have the thermal overload protective device?
Snapped-off
Well-known member
My apologies, ignore the recovery machine on center stage.I guess you learn something new every day...
I didn't realize data centers regularly needed or installed hydraulic lifts!
If you adjust your focus to the right, you can see the hydraulic lift.
corner grounded delta will do that if you use it wrong enough.
Man I must have missed where he said this lift was going in a data center! Silly me assuming it was going in a residential or maybe light commercial setting...
Now that that's cleared up, can you please recommend the purchase of a single pole breaker to supply power for this lift?
Unless you don't want to for some reason?
I have to provide the power disconnect switch. I did buy a double pole, 30 amp rated switch for that. Here's a related question; since I'm running 10-3 anyway and will have a power disconnect switch mounted on the lift column, is there any reason I can't/shouldn't put a GFI outlet in that same box? (it's a double box). It would seem I can just take one of the power legs and neutral that will be there to tap 120 V. Is there a concern about unbalancing the power to the motor if I do this? The other minor concern is that the breaker is 25 amp, but outlet is rated for 20 amp. It doesn't appear that a standard 120 V GFI outlet is available for 25 or 30 amp rating.
Cruzan80
Well-known member
And that lift uses 240V line to neutral single phase, right? That is why it is relevant to the conversation at hand...
By code no. You can't put a 15a or 20a receptacle on a 25 or 30a cb.
If you change the disconnect to a 4 circuit mini panel and add a 20a cb feeding the gfci recept then ok. Adding a 2pole 30a cb also to act as the local disconnect.
wyliesdiesels
Well-known member
you cannot have a 240v load on a single pole breaker in the US so we have no clue what youre talking about
wyliesdiesels
Well-known member
you would need a local breaker or fuse to protect the 20a (or 15a) receptacle. and you will not find a 25a or 30a rated NEMA 5-20 GFCI because it is rated for 20a (hence the 5-20 designation) not 25a or 30a.
matt_i
Well-known member
It's possible to get 240vac from a single pole breaker hooked to one of the internal bus bars for L1 and another single pole hooked to the other/opposite bus bar for L2. But then one would violate handle-tie for same circuit and then so much easier to just pickup a double pole breaker which solves all of these issues.
Lassen Forge
Well-known member
There's always good ol' 277. The wye leg of 480, commonly used for lighting, climate control, and knocking employees off tall ladders in retail outlets...
Yes, single phase. I will forego the outlet. A short extension cord will do.
sparky 1971
Well-known member
Two single pole breakers with a handle tie aren't for 240 volt circuits because they don't have a common trip. While it's possible that when one breaker trips, the other could go to the off position, that isn't the intent and is unlikely to happen. Handle ties are meant for common off with MWBC's, meaning that if you want to turn off one circuit, you will have to turn both/all three of them off to keep from blowing a up bunch of stuff from a loaded neutral. That being said, I've seen a bunch of single pole breakers with finish nails dropped through the handles over the years for 240 volt circuits; while not code compliant, it probably works better than handle ties, especially the phony POS that Square D makes.
Cruzan80
Well-known member
Sorry, Mike. That wasn't directed at you, but at the other person who keeps trying to drag obscure references into the thread. I figured yours was single phase, as +99.99% of 240V questions on here are Line/Line 1ph voltage, not L/N.
When I pointed out hydraulic (car) lifts aren't usually found in data centers, he posted a pic of a person/equipment lift, and I was checking if that (person) lift was the 240 Line/neutral he keeps insisting is relevant to this conversation.
I do "think" that something like what is pictured below is what Wylie was talking about for installing a 120V GFCI along with the 240V if you use 10/3. These appear to be "standalone" breakers or thermal cutoffs. So you could take one hot line and "branch" it to both the hydraulic lift and supply this, and the neutral would work for 120V. I am not a sparky by trade, so would probably want one of the others to confirm (also dont know if the GFCI would be ok with the "branching"). The two on the bottom have different sized options (15/20), and you would just not use/move the switch for the one on the top.
