Breaker panel capacity

Andy in ATL

Aww come on 220, The man. do an excellent job testing their stuff and they will be listed, right???

Just kidding

BigJimmy

So I know that this is WAAY off the original topic, but while we're all talking so nicely...

I have spent many years working on power plant and railroad signaling systems. Both (with the exception of office and parking lot lighting in Power Plant installations) are exempt from the NEC. That being said, most engineers who work in these areas typically use the NEC where applicable as a minimum standard, myself included. Therein, I have spent countless years reading and re-reading the NEC and it seems like every time I pick it up, I finally figure out/understand some little tid-bit that has alluded me in prior readings because the wording was misleading, nebulous, vague, etc (or perhaps I'm just an idiot!). Often, following such a revelation, I usually think "why the hell didn't they just say the obvious?" (I will admit that the big code handbook is quite helpful).

Reading through trade magazines like EC&M, you constantly find advertisements for code training seminars (I must receive a half-dozen similar solicitations in the company mail each month). Mike Holt is making a mint demystifying the code for the gen-pop but why the need? If the NEC was written to be easily understood would so many people need this sort of training? And if the NEC is supposed to be "black and white," why are there so many people arguing over things that are suppose to be absolutes?

IMHO, I've always thought that it could be written in a more straighforward manner.

TTFN,
Jimmy

__________________
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves,"You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." - George Carlin

BigJimmy

Jim: Your panel wiring is well executed but your choice of wire colors was abysmal. And, you violated section 314.16 by overfilling your boxes. Jim....You are out.

Andy: You can stay.

__________________
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves,"You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." - George Carlin

Andy in ATL

Should I laugh or be offended? As if I could BE offended.

BigJimmy

I thought that the "carry on" reference was a Tim Gunn thing. I was trying to do my best Heidi Klum!

__________________
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves,"You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." - George Carlin

Andy in ATL

I get it now.

pcampbell

This is a great point. I think that most people look at things in 120v and amps. So I have 100 amp service (240v) and I buy a dishwasher at 10 amps, thinking WOW, this 10 amp appliance is 1/10th or even 1/8th of my capacity, when it is realy 1/16th (1200 watts / 19200 watts) of my resources, at worst (since really DW does not operate for 3 hours, it is more like 2-2.5 h), assuming the rest of the house is balanced?

LawnGuyLandSparky

This is pretty much correct. You could have a 40 circuit panel, and 38 of the circuits could be 20 amp breakers, that doesn't mean each circuit is loaded to 20 amps. The panel would total 760 amps, or, 380 amps on each 100 amp leg. Perfectly complaint. Now assume the remaining 2 spaces are used to feed a 50a 2-pole breaker to feed ANOTHER subpanel. Also filled with breakers. Also perfectly compliant.

Individual circuit breakers are there to protect that individual circuit. So that you don't exceed the circuit cable's rating. The main is there to protect the service entrance cable to your home, so that your total house load doesn't exceed that cable's rating. (There are no fuses or breakers between your home's service and the utility's transformer feeding your house.)