3 phase breaker in single phase panel

[LarryFine]

Where is Larry, he know's.

"Here I come to save the daaaaayyyyy!" :grin:

Picture a typical 3ph breaker, which would pick up each phase by the stab clips. Now, because your panel only has two buses, the third breaker body has no clip, but just has an empty stab slop.

Now, to get the third phase into the third breaker body, a fourth body is added (which may have a mechanism in it, or may just be a 'jumper') which provides a terminal for the third phase to get in.

A and B phases are obtained as usual, through the MB or ML's and the panel buses and stabs, and the high leg is obtained by being routed from the 3ph meter directly to the fourth breaker body.

So, you see how easy it would be to add a high leg to an existing 1ph service. You'd only have to replace the meter guts and add a wire from the POA to the meter, and meter to Delta breaker.

You could theoretically build a Delta breaker by combining a regular 2p breaker with a 2p breaker with the clips removed and internally jumpered together. You wouldn't have the internal trip, tho.

Added: Good luck finding a 4p handle tie, too.

 

[iwire]

From ECN

 

[LarryFine]

That's the one! Looks like they made it from my description.

I like the "different" written on the box. I'll bet it was.

(Please substitute "slot" for "slop" in my previous post. )

 

[jumper]

"Here I come to save the daaaaayyyyy!" :grin:

Picture a typical 3ph breaker, which would pick up each phase by the stab clips. Now, because your panel only has two buses, the third breaker body has no clip, but just has an empty stab slop.

Now, to get the third phase into the third breaker body, a fourth body is added (which may have a mechanism in it, or may just be a 'jumper') which provides a terminal for the third phase to get in.

A and B phases are obtained as usual, through the MB or ML's and the panel buses and stabs, and the high leg is obtained by being routed from the 3ph meter directly to the fourth breaker body.

So, you see how easy it would be to add a high leg to an existing 1ph service. You'd only have to replace the meter guts and add a wire from the POA to the meter, and meter to Delta breaker.

You could theoretically build a Delta breaker by combining a regular 2p breaker with a 2p breaker with the clips removed and internally jumpered together. You wouldn't have the internal trip, tho.

Added: Good luck finding a 4p handle tie, too.

Book marked for future study. Thanks Larry.

 

[mxslick]

From ECN

Thanks Bob for posting the pics!

Perhaps the OP can contact the member at the other site if he needs to buy that breaker from him. :grin:

 

[norcal]

From ECN

Just for a bit of useless info, I found that breaker on Ebay. Would love to find a few other makes for my collection.

 

[Npstewart]

Anyone know how I calculate the load on this breaker, if I have say a 5KW load, is that translating to 13.8 amps. Thanks

 

[jumper]

Anyone know how I calculate the load on this breaker, if I have say a 5KW load, is that translating to 13.8 amps. Thanks

I believe you just use the standard 3 phase formula. I came up with 12 amps. Did you divide by 220v or 240v?

 

[Npstewart]

208 volts. Its a 208 volt service.

 

[jumper]

208 volts. Its a 208 volt service.

I thought you had a delta service?:-?

 

[Npstewart]

No, no delta service. Its a "delta breaker". The service to this site is 208-3 phase. They only brought 208-1 phase to our space though, which is why my service is 208.

I have a "delta breaker", which is used when you have a three phase load but only a single phase service, its illegal to use this now. By the way, I never heard of a delta breaker until yesterday on this forum.

Nick

 

[Phaedra]

3 phase breaker in single phase panel

I am not sure if it makes sense or not....

There is a system using 208V/3 phase. if we use single phase instead 3 phase, do we need two single phase or three single phase?


I think...

first, two single phase with ground total voltage will be 240V line1 and line 2

second, when I check 208V/3phase any line voltage with neutral is 120V

which one is right? and is it working when 208V/3phase system is connected to single phase?

Thank you.

 

[Chamuit]

I zoomed in on all your pictures.

I agree you have a single phase panel there. The panel diagram shows that.

The breaker is a delta breaker. The stinger goes in on the top lug and out on the one below it. The sticker on the breaker shows that.

5kW 5000W ? 360 (208 * 1.732 for 3 phase) = 13.89

I believe the one-line diagram from yesteryear said that it was fed with #10. That should be adequate barring distance problems.

 

[LarryFine]

208 volts. Its a 208 volt service.

It shouldn't be. You should be measuring 120v from each of the two main lines to the neutral, and 208v from the third line to the neutral. Please check again.

 

[LarryFine]

No, no delta service. Its a "delta breaker". The service to this site is 208-3 phase. They only brought 208-1 phase to our space though, which is why my service is 208.

If you have a third phase for even one piece of equipment, then you have 3 phase. You just have less capacity on one conductor.

The main disco in your other thread is definitely set up as a high-leg Delta, as is this panel with only two buses and the Delta breaker.

If you're correct about the 208v, and 120v from all three lines to the neutral, then your original Delta transformer bank was replaced.

If so, you could leave everything as it is, or replace the third-phase conductor and fuse, and install a 3ph panel to increase capacity.

If you can find the transformers supplying this building, you can tell in an instant what their service is. Take a pic if you're not sure.

 

[jumper]

If you have a third phase for even one piece of equipment, then you have 3 phase. You just have less capacity on one conductor.

The main disco in your other thread is definitely set up as a high-leg Delta, as is this panel with only two buses and the Delta breaker.

If you're correct about the 208v, and 120v from all three lines to the neutral, then your original Delta transformer bank was replaced.

If so, you could leave everything as it is, or replace the third-phase conductor and fuse, and install a 3ph panel to increase capacity.

If you can find the transformers supplying this building, you can tell in an instant what their service is. Take a pic if you're not sure.

You see why I was confused when he said 208v.

If the transformer bank was changed to a wye, wouldn't the transformers be all the same size? I know that a delta can have a larger "lighter" , but a wye?

 

[John120/240]

From the picture post #22, your line goes where marked,then does your
load go on second from right? I learn something every time I'm here.

 

[Chamuit]

From the picture post #22, your line goes where marked,then does your
load go on second from right? I learn something every time I'm here.

Here is a diagram with labels.

 

[LarryFine]

If the transformer bank was changed to a wye, wouldn't the transformers be all the same size?

They always have been the same in my experience.

A quick glance at them will tell an experienced eye.

How do I make all my lines the exact same length?

 

[cpinetree]

Picture of disconect feeding this panel

Picture of disconect feeding this panel

see attached for picture of the disconnect feeding the panel that this "Delta" breaker is in.

Also this is a 3 phase high leg service at this location not 208v.