Section 408.15

[inspector 102]

When reviewing this section, is it the intent that only 42 handles are allowed or would a tandem breaker still be considered as a single overcurrent device since the limits is 42 overcurrent devices in one panel board.

 

[wayne123]

Re: Section 408.15

I think it means 42 devices.A tadem breaker takes up one space. Read the last paragraph in that article which explains 2 pole and 3 pole breakers.

 

[bphgravity]

Re: Section 408.15

A tandem may only take up one space but it is two overcurrent devices. In other words, a tandem is a single device with two overcurrent devices in it. Like a duplex receptacle. It is a single device but is really two receptacles.

 

[chicar]

Re: Section 408.15

I recently installed a Cutler Hammer 20-24 circuit panel. 20 full size breakers or 16 full size and 4 tandem breakers. I could put 10 full size and 10 tandem breakers in this panel but the panel maximum circuit is 24 circuits.

 

[jimwalker]

Re: Section 408.15

We can not put tandems where it calls for singles.If we did we start having 84 CIRCUITS in one panel.Personally i never understood the reason to even make a combo panel.And do not like the idea.
If you using the right breakers they won't fit

[ June 10, 2004, 08:36 PM: Message edited by: jimwalker ]

 

[websparky]

Re: Section 408.15

For the purposes of this article, a 2-pole circuit breaker shall be considered two overcurrent devices; a 3-pole circuit breaker shall be considered three overcurrent devices.

 

[bphgravity]

Re: Section 408.15

I don't understand what 2-pole or 3-pole breakers have to do with tandem breakers? Isn't a tandem breaker a single device with 2 - 1 pole switches?

 

[mthead]

Re: Section 408.15

Max. number of brkrs in a panel board is 42.In this instance the manufacturers fo most panels,in a rare moment of uncharacteristic foresight,anticipated exactly this debate--they put a schematic on the back of the panel door which indicates if that panel will accomadate any twin brkrs. and exactly where those brkrs. may be placed.
The short story is you won't find a 40 ckt panel that can have any twins or quads in it.They may only be used in the 30-40 panels,12-24,etc..
The aim is to keep people from twinning a panel to death.
If you put a twin in a 40 slot panel you've just violated the listed use of that panel and made yourself the liable party should ANY elec. problem arise[from the insurance company's point of view].

 

[jii]

Re: Section 408.15

I don't understand what 2-pole or 3-pole breakers have to do with tandem breakers? Isn't a tandem breaker a single device with 2 - 1 pole switches?

408.15 specifys that a 2-pole is counted as 2 devices, and a tandem has 2 poles, weather the 2 poles are on the same phase or different phases doesn't change the fact that it should be counted as 2.

 

[bphgravity]

Re: Section 408.15

I still believe that is an improper reference. A tandem breaker is a single pole device with two overcurrent devices. The 2-pole and 3-pole statment has no bearing on this topic.