Commercial work with stab on panels

[slick 50]

Guys,

Is there any particular reasons for always using bolt on panelboards in commercial and industrial work? Is this a code or standard or just architect and engineers preference? It is so much cheeper to use stab on panels like the same you would use for residential. This is just something I have been thinking about.... Thanks for any opinions and feedback!

Bob

 

[480sparky]

Bolt-ons are typically a specification.

 

[Jim W in Tampa]

It's all about quality but not required. On small jobs often not speced but this is why you must read EVERYTHING on spec sheet.

 

[raider1]

I agree with Ken,

Most commercial and industrial work I have done the engineers spec out bolt in panels.

There is no NEC prohibition from using a stab in panel for commercial or industrial locations.

Chris

 

[jim dungar]

There is a fairly common perception that bolt-on breakers and panels are inherently of a higher quality construction than plug-on devices.

 

[benaround]

Then you have your Sq.'D' I-line panels ?

 

[iwire]

Guys,

Is there any particular reasons for always using bolt on panelboards in commercial and industrial work? Is this a code or standard or just architect and engineers preference? It is so much cheeper to use stab on panels like the same you would use for residential. This is just something I have been thinking about.... Thanks for any opinions and feedback!

Bob

To add to what the others have said watch the AIC ratings of the plug in breakers you intend to use. Jim D pointed out to me that you can get high AIC ratings even with plug in breakers but I am willing to bet you will not find them on the shelf at the supply house.

 

[hurk27]

Watch out using aluminum stab buss panels in high moisture environments, we had allot of failure of the busses in these, specially with breakers 30 amps and above.

 

[iam14sure]

Bolt on breakers

Bolt on breakers

I was told by a G.E rep. that stab on breakers are rated at 80% and bolt on are rated 100%. Don't know if it's true.

 

[480sparky]

I was told by a G.E rep. that stab on breakers are rated at 80% and bolt on are rated 100%. Don't know if it's true.

80% of what? Ampacity? If so, then we would be required to reduce ampacity in all circuits in a stab-in panels by 20%

 

[jim dungar]

I was told by a G.E rep. that stab on breakers are rated at 80% and bolt on are rated 100%. Don't know if it's true.

It is absolutely false.

Breakers built to UL489 are all rated for 80% when installed in standard enclosures. Breakers UL rated at 100% require enclosures with 'lots of' ventilation.

I know of no UL489 thermal magnetic that is rated at 100%.

 

[slick 50]

Thanks Guys,

I can see 400 amp and up panel boards being speced out to be bolt on but 200 and less should not be in my opinion but there's no easy answers:roll:

 

[iwire]

Thanks Guys,

I can see 400 amp and up panel boards being speced out to be bolt on but 200 and less should not be in my opinion but there's no easy answers:roll:

Panels under 400 amps can still have very high fault current levels that require more then off the shelf plug in breakers. Classified replacement breakers are only rated 10,000, I am looking at a Bryant plug in that is also only rated 10,000.

Many times engineers will specify 480Y/277 volt panels for 208Y/120 distribution to get the AIC rating needed.

My own experience if that I see many more failures of plug in panels then in bolt panels. This is particularly true when the breakers are used for switching. (Are plug in even rated for switching?)

In my personal opinion if your adding a panel to an existing building you should at least use equipment rated as high as the existing, if you can do that with plug in breakers go for it.

 

[slick 50]

Panels under 400 amps can still have very high fault current levels that require more then off the shelf plug in breakers. Classified replacement breakers are only rated 10,000, I am looking at a Bryant plug in that is also only rated 10,000.

Many times engineers will specify 480Y/277 volt panels for 208Y/120 distribution to get the AIC rating needed.

My own experience if that I see many more failures of plug in panels then in bolt panels. This is particularly true when the breakers are used for switching. (Are plug in even rated for switching?)

In my personal opinion if your adding a panel to an existing building you should at least use equipment rated as high as the existing, if you can do that with plug in breakers go for it.

I know Cutler Hammer has plug on breakers that are rated 10, 22, 42 KAIC and all the CH brands are rated switch duty.

 

[jim dungar]

Are plug in even rated for switching?

Square D's QO (plug-in) and QOB (bolt-on) are identical breakers, except for their bus connection. They can even be installed in an NQOD or NQ panelboard at the same time.

I believe Cutler Hammer's CH family also have the same 'guts'

UL SWD (switching duty) only applies to 15 and 20A 1P 120V and 277V breakers (they are tested similar to light switches for life cycling of fluorescent loads). There is a more severe test, often called HID rating, that addresses additional breakers.

 

[LazyS]

we never use plug in panels in offices for the simple fact that they can pop off the buss to easily, leading to a lot of pissed of "techies".And I have opened up panels where obviously the dead front is the only thing holding the breakers in because of the force of their lazily installed wires

 

[LazyS]

And if this happens, by law, you must place the dead front and panel cover back on before the screaming techies make there way down to start pointing fingers. Its helpful maybe to act like your on break and no work has been performed. Gotta us out of a few jams......I'm kidding, we always take full responsibility for what we have done............blame it on either the apprentice or the new guy and walk away to let them deal with the techies :roll:

 

[macmikeman]

I love it when the specs call for bolt, you bid it that way, loose the bid, find out later somebody used a plug in loadcenter. Anyway, about 95 per cent of the stores and fast food joints I wired in the 80's are gone. There is something else in the space and another wiring job has been done behind mine. A load center would have actually been a better choice for all of that.

 

[PetrosA]

The worst breakers I've ever seen for "popping" out of a bus have been CH. For the premium price you have to pay for them, you'd think they'd have a better design.

 

[brantmacga]

The worst breakers I've ever seen for "popping" out of a bus have been CH. For the premium price you have to pay for them, you'd think they'd have a better design.

standard QO's will do the same thing.