An existing 208/120 3 phase rated panel being used as a 240/120V 3 phase high delta type panel

[kwired]

It depends on the panel. While losd centers have limited optiond, there are some panels whuch can have their 'breaker to bus' connections moved so the high leg is not available without loosing breaker mounting space.

I ran into this on accident one time. Found out they can configure panel bus connection on NQ panels pretty much however you want. I ordered one one time and was wondering why it was taking so long to get it, because what I wanted was something I had gotten several times before from stocked components or at least a combination of items I have gotten before when building from stock components. I needed a 30 circuit three phase main lug panel bus assembly, a main breaker , a main breaker mounting kit, and a feed through lug kit, and an enclosure long enough to accommodate the main breaker kit and the feed through lugs kit. I did have some breakers on the order as well but this is what caused the confusion as I only needed one three pole breaker but did not put it on the order as I already had the one needed. Did need three phase on the feed through lugs and main breaker though.

Normally I get all the parts out of stock and have to field assemble it. My sales guy asked me if this was a high leg delta and I said yes. That changed what the software built for him when he entered the information. I ended up getting a factory assembled three phase panel with the main breaker and feed through lugs, but the 30 spaces were "120 volt prepared spaces". All were A and C phase, no connection to B phase other than the subfeed lug on the opposite end of bus from the main breaker.

I explained this won't work for me and we figured out why it got ordered that way. They took it back and I got what I actually wanted from stock in just a couple days or so. They often need to drag components from other store locations to fulfil this kind of order in short time.

This special order panel today probably takes over a year to get though the way things have been. That one (probably 2016-1019 time frame) only took around 30-45 days but was still longer than I was expecting when most those panels normally I build from stock items.

 

[ME431]

Great answers everyone! The model number does specifically request for 208/120 per Siemens info. I did also find out that it is also rated for 240/120 as many of you has expressed. But of course since it is technically custom built, there could be parts that are not rated correctly. There is liability in cases like this if information is a little vague. For this particular project it is not going to matter anyways since im going to have to upgrade the panel and cabling with higher amperage because of the new load that is going to be added to this building. I appreciate everyone answers!!

How did you determine that it is also rated for 240/120? My AHJ says in order for me to use the standard 208/120 volt on 240/120 3 phase that I would need a statement from Siemens stating that it was ok to apply 240 volts to the panelboard, even though I showed them that it is rated for 240 volts max. And, FWIW, The 208/120 volt panel is standard issue and not special order. Siemens has a 240/120 volt standard panel but Single phase only. Three phase 240/120 has to be special ordered. My only option with siemens is to order a 240/120 3 phase and wait 4 to 6 months or use a 480/277 rated panel using BL type breakers rated at 240 volts. Go figure. Also, both the 208/120 volt 400 amp 3 phase panel and the 480/277 volt 400 amp panel are the exact same price. Siemens says you can install BL type 240 breakers or 480 volt type BQD breakers in a 480 volt panelboard but you cannot use both types together.
I now have to present this to the AHJ in order to do this prior to install.

 

[electrofelon]

How did you determine that it is also rated for 240/120? My AHJ says in order for me to use the standard 208/120 volt on 240/120 3 phase that I would need a statement from Siemens stating that it was ok to apply 240 volts to the panelboard, even though I showed them that it is rated for 240 volts max. And, FWIW, The 208/120 volt panel is standard issue and not special order. Siemens has a 240/120 volt standard panel but Single phase only. Three phase 240/120 has to be special ordered. My only option with siemens is to order a 240/120 3 phase and wait 4 to 6 months or use a 480/277 rated panel using BL type breakers rated at 240 volts. Go figure. Also, both the 208/120 volt 400 amp 3 phase panel and the 480/277 volt 400 amp panel are the exact same price. Siemens says you can install BL type 240 breakers or 480 volt type BQD breakers in a 480 volt panelboard but you cannot use both types together.
I now have to present this to the AHJ in order to do this prior to install.

There was a little bit of an update regarding this, but I never did get an answer as to what is involved to get a panel board listed/marked for both systems and why they no longer offer high leg for a P1 ( I am still quite certain there is no actual physical difference, it's just administrative).

120/240 three phase (high leg) load centers and panelboards

Just a brief update here on a topic that comes up frequently. I didnt try to dig up the threads I am thinking about, but one was discussing whether three phase loadcenters were ok on a high leg delta system. The other was about using a true panelboard factory marked as 120/208Y on a high leg...

forums.mikeholt.com

I don't agree on not being able to mix BL and BQD together. I have ordered factory panel boards that came with a mix, and it says right on the dead front provisions are for type BL or BQD.

 

[ME431]

There was a little bit of an update regarding this, but I never did get an answer as to what is involved to get a panel board listed/marked for both systems and why they no longer offer high leg for a P1 ( I am still quite certain there is no actual physical difference, it's just administrative).

120/240 three phase (high leg) load centers and panelboards

Just a brief update here on a topic that comes up frequently. I didnt try to dig up the threads I am thinking about, but one was discussing whether three phase loadcenters were ok on a high leg delta system. The other was about using a true panelboard factory marked as 120/208Y on a high leg...

forums.mikeholt.com

I don't agree on not being able to mix BL and BQD together. I have ordered factory panel boards that came with a mix, and it says right on the dead front provisions are for type BL or BQD.

I read it somewhere in siemens PDF selection and application guide but can't find it now. Not an issue for me. I will still consult with the inspector prior to ordering a 480 volt interior to be sure it is acceptable on a 240 volt delta. I do not see an issue as long as I label the interior with 240/120 volt 3 phase. I wanted to go with a 74 circuit Square D 240 volt interior but their enclosure already has knockouts and I need to cut my own to match the existing FPE panel enclosure. I believe I can fit it in a siemens enclosure but there are probably objections to that also. What are your thoughts on using a 480/277 rated interior on a 240 volt delta system? This is driving me crazy and also making me learn stuff that I didn't think I needed to know.

 

[jim dungar]

This is driving me crazy and also making me learn stuff that I didn't think I needed to know.

UL lists equipment for its maximum nominal voltage.
For decade Square D 'off the shelf' panels were sold with a label that said 240V maximum, or 600V for their I-Line series, I believe they now list several voltages. Their standard QO load center is good for up to 240V 3-phase 3-wire Grounded B.

 

[electrofelon]

I read it somewhere in siemens PDF selection and application guide but can't find it now. Not an issue for me. I will still consult with the inspector prior to ordering a 480 volt interior to be sure it is acceptable on a 240 volt delta. I do not see an issue as long as I label the interior with 240/120 volt 3 phase. I wanted to go with a 74 circuit Square D 240 volt interior but their enclosure already has knockouts and I need to cut my own to match the existing FPE panel enclosure. I believe I can fit it in a siemens enclosure but there are probably objections to that also. What are your thoughts on using a 480/277 rated interior on a 240 volt delta system? This is driving me crazy and also making me learn stuff that I didn't think I needed to know.

That's actually a good idea I didn't think of, to use a 277/480 interior for a 240 high leg system then I could get it on a P1 that is presumably a little cheaper than a P2. I see no issue, and that is done frequently when high AIC breakers are needed on a 208 or 240 system. In the case of Siemens, a 277/480 BQD breaker already fits in a 240V interior and gives you 65K @240, but if you needed more you could go with a NGB but that is a different interior .

 

[gene6]

We had some issues finaling a renovation job with incorrect panel markings, the inspector was citing something in 408 in the code and they would not accept my label maker solution.
Turns out Siemens has a record of each panel they make and can just send you new stickers you install in the panel, including the big sticker with the list of breakers you can put in the panel.

 

[kwired]

UL lists equipment for its maximum nominal voltage.
For decade Square D 'off the shelf' panels were sold with a label that said 240V maximum, or 600V for their I-Line series, I believe they now list several voltages. Their standard QO load center is good for up to 240V 3-phase 3-wire Grounded B.

Yes I primarily use Square D and it is simple. QO and NQ (or any other previous QO bolt on series) is 240 volts max.
NF is for use on 480/277 - can not be used on any 480 volt delta system.
I-Line is for anything 600 volts or less, but there can be 240 volt, 480 volt and 600 volt breakers to choose from that fit this panel.

 

[ME431]

There was a little bit of an update regarding this, but I never did get an answer as to what is involved to get a panel board listed/marked for both systems and why they no longer offer high leg for a P1 ( I am still quite certain there is no actual physical difference, it's just administrative).

120/240 three phase (high leg) load centers and panelboards

Just a brief update here on a topic that comes up frequently. I didnt try to dig up the threads I am thinking about, but one was discussing whether three phase loadcenters were ok on a high leg delta system. The other was about using a true panelboard factory marked as 120/208Y on a high leg...

forums.mikeholt.com

I don't agree on not being able to mix BL and BQD together. I have ordered factory panel boards that came with a mix, and it says right on the dead front provisions are for type BL or BQD.

I found the reasoning why you cannot mix the BL types with the BQD. BL breaker heights are 3.75 in and depth is 2.37 in while BQD heights are 4.5 inch. and depths are 2.69 in. I believe mixing the two in the same panelboard would not allow the deadfront to be properly installed due to the difference in height and depth of the breakers. Also, BL breakers are 120/240 whereas BQD types are 480/277 volt and definitely in my opinion should not be mixed. I have attached the Siemens guide as a reference. Please correct me if I am wrong.

 

[ME431]

I found the reasoning why you cannot mix the BL types with the BQD. BL breaker heights are 3.75 in and depth is 2.37 in while BQD heights are 4.5 inch. and depths are 2.69 in. I believe mixing the two in the same panelboard would not allow the deadfront to be properly installed due to the difference in height and depth of the breakers. Also, BL breakers are 120/240 whereas BQD types are 480/277 volt and definitely in my opinion should not be mixed. I have attached the Siemens guide as a reference. Please correct me if I am wrong.

The information I posted above is wrong and should be deleted. After further research I now realize that only BQD breakers can be installed legally in a 480/277 volt 400 amp Siemens panelboard and not Type BL. I could not figure out how to delete the post.

 

[electrofelon]

The information I posted above is wrong and should be deleted. After further research I now realize that only BQD breakers can be installed legally in a 480/277 volt 400 amp Siemens panelboard and not Type BL. I could not figure out how to delete the post.

I'm not so sure. If the panelboard is on a 480/277 system then you certainly can't use 240 volt BL breakers. I don't see any reason why I can't use a 480/277 panel on a 240 system and use BL breakers. BL and BQD are definitely interchangeable, Siemens actually sent me a factory panel board with a mix of them.

 

[ME431]

I'm not so sure. If the panelboard is on a 480/277 system then you certainly can't use 240 volt BL breakers. I don't see any reason why I can't use a 480/277 panel on a 240 system and use BL breakers. BL and BQD are definitely interchangeable, Siemens actually sent me a factory panel board with a mix of them.

Revised 8/31/2023

 

[electrofelon]

Sure you can get into silly "manufacturer's instructions" with this stuff and a inspector with nothing better to do but waster everyone time instead of looking for things that actually matter. Personally I would have no issue using a 480/277 panel on a 208 or whatever system and use BL breakers. The panels are the exact same other than the printing on the dead front.

 

[ME431]

Sure you can get into silly "manufacturer's instructions" with this stuff and a inspector with nothing better to do but waster everyone time instead of looking for things that actually matter. Personally I would have no issue using a 480/277 panel on a 208 or whatever system and use BL breakers. The panels are the exact same other than the printing on the dead front.

The Siemens engineer attached a statement stating that all Siemens P1 panelboards are rated for a maximum voltage of 480 volts. So I am going to print a label for 120/240 High Leg C and put the statement in the panel schedule holder. I agree that all of the panels are the same. The 480/277 P1 panelboard is the exact same price, dimensions and weight as the P1 panelboard with the 208/120 volt marking. I am going to cut holes now and will not bring this up again until after the inspection.

 

[electrofelon]

So really all this just adds more confusion. Why doesn't Siemens just say their panelboards are good up to 480 volts and save a whole bunch of parts numbers? They could send a little packet of stickers with the various system voltages and you could just put it on in the field. P1s could also be used on a 240 high leg Delta system then too presumably.

 

[ME431]

So really all this just adds more confusion. Why doesn't Siemens just say their panelboards are good up to 480 volts and save a whole bunch of parts numbers? They could send a little packet of stickers with the various system voltages and you could just put it on in the field. P1s could also be used on a 240 high leg Delta system then too presumably.

Exactly. I will post the results of the final inspection. I am installing the 208/120v 400a panelboard tomorrow night on the 240v 400a delta system. and, oddly enough, the existing panelboard is 208/120v 400a which is why they ordered this one to begin with.

 

[ggunn]

So really all this just adds more confusion. Why doesn't Siemens just say their panelboards are good up to 480 volts and save a whole bunch of parts numbers? They could send a little packet of stickers with the various system voltages and you could just put it on in the field. P1s could also be used on a 240 high leg Delta system then too presumably.

I agree; it would be very expensive for equipment manufacturers to build different gear and use different components for every different voltage and/or current rating.