Bolt-on v/s Plug-in type circuit breaker applications 1

[katwalatapan]

Hello,

I wanted to inquire about general opinion about typical applications for Bolt-on and Plug-in type circuit breakers.

I understand that typically bolt-on type breakers are preferred in commercial/industrial applications where vibration may be an issue whereas the plug-in type breakers are typically used for residential applications. Would there be any other specific considerations where bolt-on type are preferred or required over plug-in type circuit breakers?

Thank you.

 

[itsmoked]

In a case like a control panel you wouldn't want to waste the space having a redundant enclosure as needed for plug-ins so you'd want bolt-ins.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[jraef]

As a general rule, residential style plug-in load centers and their associated breakers are known to be cheap and risky, but the demands of a residential installation are so low that even that risk is outweighed by the lower cost and convenience of a home owner being able to remove, replace and dispose of a defective breaker with relative ease and without having to disconnect power from the source. A bolt-on breaker would preclude that because the HO would be making contact with the bus directly, so the only way for them to be safe might be to call the PoCo to kill power to their service (if for example the Main breaker is in the same box).

In a commercial / industrial setting with established safety procedures and professional electricians, you are going to have a coordinated distribution SYSTEM, so a load center with those bolt-on breakers will be fed by Feeder Circuit Breaker in another larger panelboard up stream. Therefore, needing to make contact with the bus bars to replace or add a breaker can be done more easily by opening and locking out the FCB for that panel. You will not generally find many large commercial or industrial facilities that would allow plug-in load centers because their insurance carriers will forbid it.

Keith,
I think he means the type that bolt on to the bus bars, not the mounting panel. Bolt-on breakers still need bus bars, so still end up with the redundant box if going in a control panel. The term used for what you are referring to is a "panel mount" breaker, lug in, lug out, no bus.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[itsmoked]

Ah, thanks for the enlightenment Jeff.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[katwalatapan]

Thank you very much for sharing your knowledge and experience. Cheers!

 

[Mbrooke]

The truth is a plug in breaker system is not as reliable as a bolt on under heavy loads going on over the years. This does not usually hold true for light commercial and residential, but does so for industrial.

 

[itsmoked]

I'd agree Mbrooke as long as the bolt-ins are occasionally checked for tightness.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[edistur]

There are industrial/marine plug-in breakers in the market but those are expensive. If we refer to API RP 14F 5.6.6.2 requirements/recomendations those breakers should be specified for some Naval/Marine applications.

 

[VTer]

Square D uses I-line plug in style breakers that have proven reliable over the years. They are very popular in commercial and industrial applications around this area.

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic ù and this we know it is, for certain ù then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". û Nikola Tesla

 

[mcgyvr]

I use plug in (.250" quick connect and 5/16 bullet style plug in) Airpax breakers in Telecom central office/outside plant cabinet applications all the time..
.1 to 150 Amp ratings
They plug in and a screw down faceplate ensures they stay there..
The meet office vibration all the way to Zone 4 earthquake testing..