SWD Rated Breakers

[hutch75]

Does anyone know what Code cycle included the requirement of SWD rated breakers for 277 and 120 volt circuits, ie 240.83(d)? In the 1978 NEC it included 120 volt circuits only and referenced that 277 volt breakers generally have heavy duty contacts.

My question relates to a plant that wants to replace every breaker in every panel that could possibly be used as a switch for a lighting circuit. My arguement is that this plant and panelboard were built in the 1960's, and met code then, and the breakers are used infequently if at all to de-energize lighting circuits. Second problem is that the panels are very old, and in some cases the entire panel will have to be changed to install SWD breakers.

Any thoughts?

 

[petersonra]

I don't see anything wrong with their request. It may be unnecessary, but why turn down work? You don't object to people requesting more receptacles than the bare minimum that code requires do you?

In some respects it depends on what your involvement is. If your responsibility is for costs, then you might want to point out you feel it is not required to change them out. If you are an outside contractor just implementing something they have already decided on, I'd be inclined not to argue with them over their decision, although you might want to point out tactfully your opinion it is unnecessary.

 

[hutch75]

I am the plant management, and am answering a request from the plant Electrician's.

 

[petersonra]

I am the plant management, and am answering a request from the plant Electrician's.

A 40 year old electrical system might well be in need of more extensive refurbishment than swapping a few breakers. It is also quite possible that after 40 years your plants electrical system has been modified to the point where some parts of it are overloaded.

My inclination would be to do a survey of what is there and start upgrading where and if necessary, but not to do anything on an ad hoc basis like what the plant's electrician seems to be suggesting.

You will spend a lot more money over time fixing things here and there than going in and just doing it right once. less down time too.

Since you are the plant manager, you should be able to get some money appropriated for upgrading the electrical system where it is needed, and/or helpful.

I would also be concerned about the availablility of spare parts. While you can often find rebuilt or replacement parts for some of this old stuff, it is not always very fast or easy to do so. Taking some of the old stuff out and replacing it with new could well give you the spare parts you might need to keep the rest of the old stuff going.

 

[bkludecke]

If the CBs are not used for switching then they do not need to be rated for such use. If they are used for switching and replacement is unreasonably high then you may consider adding switches or contactors to do the switching and leave the CBs alone.

Just because it's old does not mean it's no good; just look at me.