Don’t do that! You have three-phase distribution. This is a diamond in the rough. You’re probably already paying for it and don’t know about it.
Give your test metre a 10 minute workout and come back with the results...
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220 off a single pull 20amp
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Don’t do that! You have three-phase distribution. This is a diamond in the rough. You’re probably already paying for it and don’t know about it.
Give your test metre a 10 minute workout and come back with the results...
Note: Any 2 pole used on the high leg & any other phase MUST be rated for 240 volts, standard 120/240V breakers cannot be used, there plenty of space so it is not a issue, straight 240V breakers are very expensive & uncommon.
This thread is just another reason why people who think 110, 220, volts still is used should not do any electrical, knowing the nominal voltages one is working on is important
This thread is just another reason why people who think 110, 220, volts still is used should not do any electrical, knowing the nominal voltages one is working on is important
alfredeneuman
Well-known member
I have a similar installation in my home shop. It is separate from my home on its own service/meter. It is my understanding that the high leg should be Orange, not red, by current code.
In my case, I have the 3phase panel as the main and a smaller single phase fed from that. Mine came about because the original single phase service main breaker failed and I added the 3phase instead of just replacing the main breaker. I lucked into a really cheap panel loaded with breakers and my provider installed the added wire and transformer at no charge. I needed it for my compressor and table saw. Well, I didn't strictly need it, as I could have bought single phase motors, but would have cost much more.
But, it is a good solution that can prevent accidentally grabbing the wrong open slot. Just use one panel for single phase loads and the other for 3ph.
In my case, I have the 3phase panel as the main and a smaller single phase fed from that. Mine came about because the original single phase service main breaker failed and I added the 3phase instead of just replacing the main breaker. I lucked into a really cheap panel loaded with breakers and my provider installed the added wire and transformer at no charge. I needed it for my compressor and table saw. Well, I didn't strictly need it, as I could have bought single phase motors, but would have cost much more.
But, it is a good solution that can prevent accidentally grabbing the wrong open slot. Just use one panel for single phase loads and the other for 3ph.
alfredeneuman
Well-known member
Although it's sometimes called a "Red Leg Delta", the high leg is required to be Orange, NEC 110.15 and on the "B"Ø.(except for San Francisco, where it's required to be purple)
Power Companies generally supply it as the "C" leg, because of metering issues.
The electrician is responsible for swapping them in the first place possible beyond the meter.
WHY?! Most people on here can only dream of having three phase in their shop.
If working in this panel bothers you that much then install a single phase sub panel next to the old one. Run all your 120v circuits out of the new panel. Normally this is done for extra space, but it also eliminates any confusion and possibility of a 120v circuit being placed on the high leg.
OP
Need more space
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Paying for it as in the price of the shop?
OP
Need more space
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I guess I never thought of it that way, I just currently have no need for it so I didn't really see its value. I'm just happy there's room to wire my hoist and compressor when it shows up.
OP
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It really opens up your options for machinery. Lot's of used industrial machinery, air compressors, lathes, mills, welders, grinders, ect are 3 phase. This stuff is often dirt cheap for high quality equipment because many homeowner types can't run them.
Three phase Delta with the hot leg on C (or L3).
You can put a three pole (three phase) breaker anywhere. Two pole (240v) anywhere. Single pole (120v) in #1, #2, #4, #5, #7, #8, etc. NOT #3, #6, #9 etc. NOT the third slot and in every third slot after that.
Simply fabulous if you have that in a residential area. I would be thrilled.
wyliesdiesels
Well-known member
As pointed out above the hi leg should be on B phase/L2 and yours is on C phase/L3...
Those all look pretty good to me. And your high leg is L3, like I kind of assumed. It should really be put on the centre. Those are your six different voltages and three different phases.
wyliesdiesels
Well-known member
Ive had guys tell me theyve used the hi leg for 208v loads line to neutral. I always thought it was a bad idea. What is the reasoning why it shouldnt? Because there isnt a transformer coil for it? Why does that matter?
And straight rated breakers ARE available, albeit pricey. They were mainly used for corner grounded delta systems.
There are no single pole breakers made for loadcenters that are rated for 240V, could use a 480/277V panel & use single pole 277V breakers, it's been done when a higher AIC rating was needed, but the high leg is not intended for L-N loads, but nothing wrong w/ using it & another phase for a straight 240V load as long as the 2-pole breaker was rated for 240V.
wyliesdiesels
Well-known member
Cant get a straight rated single pole breaker for corner grounded delta? I had someone tell me thats what they did...
On the breaker it has to say 1 pole Type, 240-300 v.a.c UL. The external plastic or internal sheathing, heat load has to be rated for that voltage. Each insulation has its own factor. The higher the voltage potential, the higher insulation factor needs to be.
For fun compare A 30 amp 250vac fuse to a 480vac(or 600vac)....
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TRWham
Well-known member
As I always understood, the neutral is sized for the 2 phases (A & C) that it should carry, but adding B to it can overload the neutral. The maximum imbalance the neutral could carry if nothing were on one phase and the other fully loaded would be equal to the phase current of the other and the neutral wire then is already maxed out. Add any load at all from the third phase and it would be overloaded. I'm sure most installations don't come close to such a situation, especially if there is a good mix of 240V loads, so you can probably get away with it in many cases.
wyliesdiesels
Well-known member
Yeah Ive seen some Delta services with reduced neutrals. But not all of them are.
Only if you use a 277V breaker.
wyliesdiesels
Well-known member
Which obviously wouldnt be listed for a 120v/240v panel.
OP
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What would be the best way of fixing that ( or just let it be? ) if I'm understanding correctly I would turn power off at meter, then switch the wire or just move the breaker on #2 and #3 of the main braker?
wyliesdiesels
Well-known member
Just tape it orange and leave it alone.
Yep, just leave it, (unless you’re having it inspected in the near future) unless you’re required to change it. You now know what you have.
It seems to me that you do not have any three phase requirements. I do and when I go to a plug or outlet, I always like to have the prong opposite of ground being my High leg. It just helps me troubleshoot for coil voltages.
It seems to me that you do not have any three phase requirements. I do and when I go to a plug or outlet, I always like to have the prong opposite of ground being my High leg. It just helps me troubleshoot for coil voltages.
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OP
Need more space
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Good deal, thanks for all the information! Ill repost in the thread when I add my hoist and compressor wiring.