415/240 WYE

[mbrooke]

If this project was outside of North America, that would be a viable solution. But these breakers are not UL listed at 240V single pole, so cannot be used that way here.

But if the project was outside of North America, 415/240V would be the norm, not the exception and the question would not have needed to be asked at all...

Right, so if the physics are constant across the globe, why not here?

UL should be able to list them and the panel at 240 volts L-G.

 

[mbrooke]

I just use a standard 480Y/277V lighting panelboard, like the Square D type NF. No need to think outside the box.

You're spending more $$$$$ which could be in your pocket and the customer's.

 

[kwired]

The problem you will run into is that for the most part, the inexpensive single pole breakers you are likely thinking of are NOT rated to be used on 240V 1 pole. Most small MCCBs are "slash rated", meaning rated 120/240V where the maximum voltage TO GROUND cannot exceed 120V. So to use a 415/240V system, you must use "fully rated" 1 pole 240V breakers, which will be the larger more expensive MCCBs anyway, and maybe more importantly, harder to get quickly if you have to replace one, because hardly anyone uses them. True, you can get more 240V circuits in a panel that way, but the panel will be bigger to start with.

A typical 277/480 panel and breakers should work. Yes they will cost more than the typical 120/240 designed equipment generally does.

 

[mbrooke]

A typical 277/480 panel and breakers should work. Yes they will cost more than the typical 120/240 designed equipment generally does.

Why do they cost more?

 

[Carultch]

Why do they cost more?

You have to make all the insulation components between the live parts withstand the higher voltage. You also have to mitigate the electrical arc driven by a higher voltage as the contacts separate upon trip or disconnecting. You also have to pay for the testing lab to test it at a higher voltage.

Both voltage and current will drive the price of equipment. It depends on the nature of the equipment in question, as to which factor will have a greater impact on price. Current you pay for conductors; voltage you pay for with insulators, arc mitigation, and UL testing procedures. In the big picture, there is an advantage to selecting higher voltage the greater the scale of power and distance, even if circuit protection components are more expensive.

Right, so if the physics are constant across the globe, why not here?

UL should be able to list them and the panel at 240 volts L-G.

It's more of a lack of testing, than any proof that you'll have any physical consequences, as to why UL doesn't list the breakers for 240V line to ground. There simply isn't as much of a market in the US, for even doing that test in the first place, since most breakers are used in 240V line-to-line applications, are used with 120V line-to-neutral. There are straight-rated breakers that don't "care" where ground is, within the 240V window between the energized parts, but you have to read the fine print to know whether you have that rating or not. Usually it is high-leg and corner-grounded systems, where it is important to look for 240V straight-rated breakers.

Yes, physics are constant across the globe, but legally enforceable construction standards are not. You would need special permission from the AHJ to take credit for foreign product ratings, and that is unlikely to happen. The AHJ can approve it in theory, but I would not expect an approval in reality. It is common that the approval is based on product listing according to nationally recognized testing laboratories such as UL, rather than according to the testing laboratories accepted in other countries

 

[tortuga]

Right, so if the physics are constant across the globe, why not here?

UL should be able to list them and the panel at 240 volts L-G.

Do you have any idea how much it costs to get something UL listed? This is a rare 'corner case' use for these within the US. Sure it would save money and yeah the OP could go for it.
Like I said I personally I would use a 480/277 panelboard for a 415/230 service job done, I use panelboards for 240 Delta all the time.
So I am 'academically' speaking here, trying to dispel the myth that 'everything' needs to be listed.
Its better when the NEC contains 'construction specifications' and manufacturers like GE can provide documentation for these obscure uses.

So that leads me to the question, I must be missing something obvious, where in the code does it say branch circuit breakers need to be UL listed?

I searched for 'listed' and came up with:
The only breaker that needs a UL listing is an AFCI in 210. 12.
230.66 for the service equipment.
240.83(D) if breakers are used as switches.
240.91 Over 800 amps
408.54 can't have more breakers in a panel than its listed for.
Might have missed it its been a long Friday...
My guess is IF branch circuit breakers need only be approved [2020 NEC 110.2], to get the approval of an AHJ you probably need a listing..

Cheers all

 

[mbrooke]

One must remember that both 240 and 480 volt panelboards are designed with delta systems in mind. Meaning full line to ground voltage, along with the transients which accompany an ungrounded system. Just think about it...

Regarding the breakers you're correct, slash rated versions take advantage of the lower line to ground voltage to achieve a normal/higher AIC.

 

[kwired]

Why do they cost more?

Purchasing entire panel and breakers as one order - might not be too significant of a difference.

Purchase one Square D NF breaker "over the counter" vs the equivalent QO breaker and you will think they raped you on price.

Purchase QO's as a single order for the entire job and you get better pricing as well though. Usually only get a lump sum price for the job, but kind of works out that single pole breakers are nearly given away compared to over the counter price, always order more of those than you need to put into your own stock on those jobs.

 

[mbrooke]

Purchasing entire panel and breakers as one order - might not be too significant of a difference.

Purchase one Square D NF breaker "over the counter" vs the equivalent QO breaker and you will think they raped you on price.

Purchase QO's as a single order for the entire job and you get better pricing as well though. Usually only get a lump sum price for the job, but kind of works out that single pole breakers are nearly given away compared to over the counter price, always order more of those than you need to put into your own stock on those jobs.

What price multiplier are they giving you?

 

[kwired]

What price multiplier are they giving you?

For a purchase of a single NF breaker not a good one. If you need maybe 4-6 three pole breakers, it cost less to submit a small project quote and get a panel with those breakers. Can just be smallest main lug panel you can find plus an indoor cabinet to go with it, then throw the cabinet and panel bus on scrap metal pile if you wish, get a little back on them when you scrap it.

That is how they want to sell these - by the job. Or else make a killing when someone is buying individual items at a time.

 

[mbrooke]

For a purchase of a single NF breaker not a good one. If you need maybe 4-6 three pole breakers, it cost less to submit a small project quote and get a panel with those breakers. Can just be smallest main lug panel you can find plus an indoor cabinet to go with it, then throw the cabinet and panel bus on scrap metal pile if you wish, get a little back on them when you scrap it.

That is how they want to sell these - by the job. Or else make a killing when someone is buying individual items at a time.

I've seen new jobs where the panel is loaded with spares. Not sure if that has anything to do with it.

 

[Carultch]

I've seen new jobs where the panel is loaded with spares. Not sure if that has anything to do with it.

It's a lot cheaper to have spares in the panel, than it is to buy spares later when you need them. There are economies of scale that make this work. Plus, the ability for the supply house to get more from you, when you are in a pinch to source that missing breaker, or to source the breaker for which you forgot to specify GFCI or AFCI. You can find breakers from online suppliers that may be a little more cost-effective, but there still is an advantage to having them come built-in the panel is first made. If you have doubts about whether you need 12x 20A branch breakers for lighting and receptacles, as opposed to 10x such circuits, you put 12x breakers in the panelboard today, and the remaining 2 breakers are there if you need them. Job specs even spell out to add spares, to plan for the possibility that the owner wants to expand in the future.

Suppose you do a lot of work, where you routinely need to add a couple branch circuits to a existing panelboards, and there are prevailing norms for what brand is most common in your region. It can be more cost effective to buy a panelboard of 30 branch breakers, and scrap the can and interior, than it is to buy 30 branch breakers individually.

 

[LarryFine]

The first time I ordered a loaded bolt-in panel, I was AMAZED at how much less it cost, PLUS the labor was done.

 

[kwired]

It's a lot cheaper to have spares in the panel, than it is to buy spares later when you need them. There are economies of scale that make this work. Plus, the ability for the supply house to get more from you, when you are in a pinch to source that missing breaker, or to source the breaker for which you forgot to specify GFCI or AFCI. You can find breakers from online suppliers that may be a little more cost-effective, but there still is an advantage to having them come built-in the panel is first made. If you have doubts about whether you need 12x 20A branch breakers for lighting and receptacles, as opposed to 10x such circuits, you put 12x breakers in the panelboard today, and the remaining 2 breakers are there if you need them. Job specs even spell out to add spares, to plan for the possibility that the owner wants to expand in the future.

Suppose you do a lot of work, where you routinely need to add a couple branch circuits to a existing panelboards, and there are prevailing norms for what brand is most common in your region. It can be more cost effective to buy a panelboard of 30 branch breakers, and scrap the can and interior, than it is to buy 30 branch breakers individually.

This generally the case with bolt on breakers both 120/240 and 277/480.

Plug on breakers and "loadcenters" not so much the case, especially for single pole 15 and 20's.

 

[kwired]

The first time I ordered a loaded bolt-in panel, I was AMAZED at how much less it cost, PLUS the labor was done.

I only had one factory assembled panelboard that I can recall. Most my projects they still sell all the components and you field install them. Including main breaker and main breaker kit when needed. Faster time that way then waiting for factory assembly.

Though my sales rep messed up one a couple years ago. Wanted NQ three phase 200 amp main breaker panel with feed thru lugs and a few breakers. Somehow he ordered it with all 30 spaces "prepped for 120 volts" (and it was a high leg delta supply) so that led to them factory assembling a panel with three phase bus, but only fingers for attaching breakers to the two outer poles. I wondered why it was taking forever for it to arrive until I saw what I got. I did need to install some three pole breakers in this panel and that was not going to work with what they sent me. My replacement came from stock items, pretty much immediately.