3 phase electric ?
- Thread starter locomike
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Franz©
Banned
Yes, BUT
If the 3Ø is an open delta or wildcat all 3 phases will not be 120 volts to neutral. If your single phase requirement is for 220v it's not a problem.
If the 3Ø is an open delta or wildcat all 3 phases will not be 120 volts to neutral. If your single phase requirement is for 220v it's not a problem.
PxTx
Well-known member
What is it that you are hooking up to the outlet?
Right now the receptacle isn't connected at the main panel and I need to try to find out which wires are for the receptacle. There are some grouping of wires that are taped w/ the machine that used to be there. There are a couple of triple pole breakers still in the box so I should just have to connect a grouping of the 3 wires to the breaker and check for juice at the receptacle? Then from there just cap off and disconnect one of the hot legs for 220v?
PxTx
Well-known member
Sounds like you've got a handle on what you've got to do. Even though you don't need 120, sometimes you need a neutral wire if the component has a 120 "control" component. For example a welder with a digital panel, probably has a 120v feed for the control.
What I'm saying it to make sure you have both a neutral and a ground.
What I'm saying it to make sure you have both a neutral and a ground.
You will all most never have a grounded conductor in a 3 phase plug. They make them but they are rather rare and have 5 prongs. So if you have a 3 phase receptacle that has 4 prongs you will not have a grounded conductor. You also may not have 220V/240V at the outlet, as that is not a given with 3 phase plugs either. In fact unless you have a 240v delta service you will not have 240V between the hot conductors. IF you do have a 240v delta service every third hot conductor will not be 120V to the grounded conductor. There is another low voltage common 3 phase system in use in the US called a 120/208 wye system. If that is what you have, you will not get more than the 208V between hot conductors (this can cause problems with some motors) but, you will be able to use all your breaker panel spaces for 120V use.
So
If you need a higher than 200V recepticle, either the delta or the wye service will be ok using any 2 hot conductors, and a grounding conductor.
If you need a 120V/240V ( 4 wire circuit ) You must make sure that you don't have the hot leg of a delta service as one of the conductors ( ie. about 200v to the grounded conductor) as your 2 hots in the circuit.
William...
So
If you need a higher than 200V recepticle, either the delta or the wye service will be ok using any 2 hot conductors, and a grounding conductor.
If you need a 120V/240V ( 4 wire circuit ) You must make sure that you don't have the hot leg of a delta service as one of the conductors ( ie. about 200v to the grounded conductor) as your 2 hots in the circuit.
William...
mike944
Well-known member
Basically, you need to go into your breaker panel, and measure your hot-to-neutral voltage and phase-to-phase voltage on all three phases.
Make sure your welder can handle whatever voltages you have, otherwise you'll need a transformer.
Make sure your welder can handle whatever voltages you have, otherwise you'll need a transformer.
O.K. I checked sometime back and I remember one of my readings was like 244v between two of the legs. Someone then said I had 240delta. What readings do I need to measure between? Between each of the hot legs and between each leg and the neutral? Here is a couple pics of my box if that helps. The subpanel to the right is single phase and I would just use it but I already have the wiring down stream to where I want to put the outlets from the other panel.
I have a 230v welders so should be alright a?
I have a 230v welders so should be alright a?
Attachments
PxTx
Well-known member
If the welder is rated for 230volt- I beleive the machine is designed to operate at voltages +/- 10%- so if you have between 253 and 207 volts, you should be okay.
Franz©
Banned
Based only on what I can see in the pictures, it well may be an open delta service. If the color tape on the center conductor feeding the panel is ORANGE it's an open delta.
If you have a grounded conductor you don't have an open delta ( and it appears that you do). If you remember correctly and you have about 240V hot to hot you probably have a corner grounded delta. So every 3rd breaker position will be a wild leg ( ie. above 190v to the grounding conductor {the "neutral" white conductor in your box }) So just make sure that if you have a high voltage to the grounded conductor you don't use that on any receptacle that needs 120V. If you do, you WILL let out the magic smoke from almost any thing you plug into it.
William...
O.K want to make sure I get all this right. By the way "lots of help".
1. I have a corner grounded delta.
2. If every third breaker along with the (neutral/ground bar)? reads over 190v. Is that what you mean?
So for example. I could use single phase 120v also by using either of the 1st or 2nd legs and the (neutral/ground bar)? I have regular 120v ran off of it for lights so I am assuming that is how it was done?
And I assume it is a ground bar on both sides of the panel. There are 2 of them if you notice in the pic.
And THANKS for the help. I'm pretty much self taught on everything I know and alot of the info comes from forum's like this. Mike.
I look at the pic now and I see that I have a single pole breaker on what looks to be a 3rd breaker though.
1. I have a corner grounded delta.
2. If every third breaker along with the (neutral/ground bar)? reads over 190v. Is that what you mean?
So for example. I could use single phase 120v also by using either of the 1st or 2nd legs and the (neutral/ground bar)? I have regular 120v ran off of it for lights so I am assuming that is how it was done?
And I assume it is a ground bar on both sides of the panel. There are 2 of them if you notice in the pic.
And THANKS for the help. I'm pretty much self taught on everything I know and alot of the info comes from forum's like this. Mike.
I look at the pic now and I see that I have a single pole breaker on what looks to be a 3rd breaker though.
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Franz©
Banned
The pis shows a single phase panel to the side most likely handling all single phase loads. The 2 busbars that panel is fed from will have 120 volts to neutral. The third phase (wildcat) can display a voltage anyplace from 60 to 200 volts to neutral depending on a number of circumstances.
The difference in nomenclatures Open Delta, and Corner Grounded Delta are primarily geographic. Different PoCos use different nomenclatures.
If the color tape on the center wire is ORANGE it's a wildcat. If the color tape is RED it isn't.
At one point in time the common practice in the NorthEst part of the country was to bring the wildcat phase down the center buss. There was a change to that practice a number of years ago when all new services were required to bring the wildcat down the righthand buss.
The difference in nomenclatures Open Delta, and Corner Grounded Delta are primarily geographic. Different PoCos use different nomenclatures.
If the color tape on the center wire is ORANGE it's a wildcat. If the color tape is RED it isn't.
At one point in time the common practice in the NorthEst part of the country was to bring the wildcat phase down the center buss. There was a change to that practice a number of years ago when all new services were required to bring the wildcat down the righthand buss.
Ah ha, found something out tonight. I found my WILDCAT. If you look very closely in the pic you will see orang tape ( i never even noticed in person) on legs of the panel. Guess what? I checked them with the meter and I get 216v to neutral. Looks like there all in the center. The other 2 legs give me 124v to neutral and 247v hot to hot.
On my subpanel I only have 1 bus bar so is this a neutral and ground bus? And on the 3phase panel I have 2 bus bars. This stuff is all starting to make sense now.
On my subpanel I only have 1 bus bar so is this a neutral and ground bus? And on the 3phase panel I have 2 bus bars. This stuff is all starting to make sense now.
MXtras
Well-known member
No they are very specific systems and there shouldn't be any ambiguity with them based on region or location.
Also I was wrong in my above message, you can have a corner or center tapped configuration using an open delta.
Additionally I should have made it clear that you louse 1/3 of the breaker spaces and not that every 3rd breaker is a high leg. It can be that way depending on the way you hook them up but it will not always be true.
BTW why did I think that you live in Montana?? Didn't you post some thing about Montana power??
In your sub panel you should NOT have the grounding conductor and the grounded conductors bonded into one buss. The Grounded conductors should be isolated from the can. You can add another grounding conductor buss strip to the can for your equipment grounding needs.
William...
That one shows a center taped/grounded delta and he could have that, or a center taped/grounded open delta. The way to know is have him look at the number of transformers on the pole. The power co's liked to use the open delta because it can be done with 2 transformers instead of three. Also if the load was not balanced ie. you have a large need for single phase you can make the center tapped transformer a larger size to carry the higher load.
William....
In your sub panel you should NOT have the grounding conductor and the grounded conductors bonded into one buss. The Grounded conductors should be isolated from the can. You can add another grounding conductor buss strip to the can for your equipment grounding needs.
You mean I should have another bus in the subpanel. Currently it has grounds and neutrals all connected to one bus. That's the way it already was.
You mean I should have another bus in the subpanel. Currently it has grounds and neutrals all connected to one bus. That's the way it already was.
Also: the outlet that I am talking about changing. I looked at it closer and opened it up last night. It is a 20amp 250v receptacle. I took it apart and it has only 3 wires connected and one capped off. I thought 3 phase would have 4 wires hooked up and I only saw where there could be 3 connections on the back of the receptacle. Only push in style also, no screw terminals.
MXtras
Well-known member
It sounds to me that because your neutral and ground are one in the same that this might be a sub-panel - is that right?
Scott
Scott
Yes, is that alright? Been that way forever I imagine and I have no problems. Pretty sure I got the 3 phase stuff now. I'm good as long as I stay away from the hot leg? Got to get the right wires hooked to box so I can change that receptacle out.
Alright is a subjective thing
It hasn't been allowed for a long time in the NEC code. IF it was MINE I would fix it. It will only cost you about $6.00 to get a small ground buss bar, and a few min to remove the bonding screw from the neutral buss to the can, and lastly mount the new ground buss and move the equipment grounding conductors to it.Your call as your probably grandfathered in with the old stuff.....
BTW did you ever say with your trying to run ?? If it's a motor load convert it to 3 phase and USE the 3 phase your paying for!!
William...
I'm just wanting to hook up another couple NEMA 6-50R for welders and such. I'm just trying to use the wiring that is already there instead of run new conduit (block building) and wiring and I don't have any 3 phase equipment. Well except for the compressor.
MXtras
Well-known member
Check the wire size. If it was a 50A three phase circuit and you are expecting the wire to carry 50A of single phase, you might be preparing for some disappointment.
Scott
Scott
Franz©
Banned
I don't live in Montana, I'm just very conversant with the Montana Power business model. Every damn PoCo in the country is trying to emmulate it, and screwing the pooch magnificently in the process. I'm getting SERVICED by the famous Rochester Gas & Electric, and you can make the farmer inference on the word service. RG&E managed to go from one of the best companys in the country to a complete whorehouse in just 6 years. Of course 1 lawyer and a handfull of his pals made a ton of money on the deal.
Well I went into the garage tonight and hooked up some of the different groupings of wires then went and checked for juice at the 2 outlets I have been speaking of. On the 2nd try I had good luck. Measured voltage for each wire and it all came out right. The wiring is 12ga. So if I convert to single phase for my welders all I can run is a double 20. Both welders I have now call for double 30's. If I run a double 20 will I keep tripping the breaker?
Now all I have to do is cap off the WILD leg and I will be all set for my NEMA 6-50R, correct?
Now all I have to do is cap off the WILD leg and I will be all set for my NEMA 6-50R, correct?
Franz©
Banned
How many wires size 12 do you have from the outet to the panel?
If you have 4 you can paralell them up and have 40 amps of wire capacity.
If you have 4 you can paralell them up and have 40 amps of wire capacity.
Franz©
Banned
1) identify each wire by doing a continuity check to ground and number wires 1 , 2, 3, and 4 on both ends
2) connect 1 & 3 together at breaker end on same terminal of 40 amp breaker
3) connect 2 & 4 together at breaker end on same terminal of 40 amp breaker
4)connect 1 & 3 together at breaker end on same terminal of outlet
5) connect 2 & 4 together at breaker end on same terminal of outlet
You now have a 40 amp capacity at the outlet.
2) connect 1 & 3 together at breaker end on same terminal of 40 amp breaker
3) connect 2 & 4 together at breaker end on same terminal of 40 amp breaker
4)connect 1 & 3 together at breaker end on same terminal of outlet
5) connect 2 & 4 together at breaker end on same terminal of outlet
You now have a 40 amp capacity at the outlet.
Charles (in GA)
Well-known member
And you have just double tapped the breakers....... a no... no. And..... Paralleled cables smaller than 1/0, not allowed in this instance by 310.6
Charles
LOL, ? I already have some single phase breakers that have been double tapped (by someone else) for lighting. I'm going to jail? O.K. update me whether I can do what he said? This has been a very informative thread for me. I hope it helps others cuz there isn't alot out there on 3 phase. I don't think it is that difficult once you check all your voltages and pay attention to what your doing. Thx.
Franz©
Banned
Zealots with code books will begin picketing your building within minutes of doubletapping a breaker in that 3Ø panel.
It's interesting to see codezealots going into freakout. They fail to understand how the world really functions, and wonder why they don't get industrial jobs being forever purged to the world of Romex. Then again, I've only been making electrons go where I wanted them since the 1950s. I'd love to see the zealots when they find a house built in 63 when Romex first came with ground wire, and nobody had a hard rule how to handle that ground. There are a few thousand houses in my area where the inspectors insisted the wire just be cut off where it entered the box.
NEC is a wonderful thing, but is simply isn't enforced because there are too many opinions on what the book says. I can show you 8 story office buildings downtown containing way over 200 people where inspectors have signed off on Romex and subfeed cable, including one where the switchgear burned. Post fire the switchgear was rebuilt and reconnected to subfeed.
It's interesting to see codezealots going into freakout. They fail to understand how the world really functions, and wonder why they don't get industrial jobs being forever purged to the world of Romex. Then again, I've only been making electrons go where I wanted them since the 1950s. I'd love to see the zealots when they find a house built in 63 when Romex first came with ground wire, and nobody had a hard rule how to handle that ground. There are a few thousand houses in my area where the inspectors insisted the wire just be cut off where it entered the box.
NEC is a wonderful thing, but is simply isn't enforced because there are too many opinions on what the book says. I can show you 8 story office buildings downtown containing way over 200 people where inspectors have signed off on Romex and subfeed cable, including one where the switchgear burned. Post fire the switchgear was rebuilt and reconnected to subfeed.
Here you have a guy (locomike ) who hasn't a clue what he's doing and Franz who is one person doing electrical work since 1950 advising him to throw the NEC code (that has been in development for 100yrs. or so) out the window.
Shock and Fire. Thats what the code is all about.
It'll still burn your building down and shock someone long after you are not around.
Code Zealot AKA Mark
IBEW LU #595 inside wireman since 1969
Electrical contractor and master electrician
Shock and Fire. Thats what the code is all about.
It'll still burn your building down and shock someone long after you are not around.
Code Zealot AKA Mark
IBEW LU #595 inside wireman since 1969
Electrical contractor and master electrician