200 amp service

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beardog

New member
Is there a code on the total circuit-breaker amperage. Can you assume that it's not over loaded if it never trips the main breaker?

beardog
 

torcho

Member
Location
Wyoming
Re: 200 amp service

No, there is no limit to the sum of total overcurrent protection devices...you are limited to 42 total devices per panel board. What does matter, is the Calculated Load, Have you done a load calculation?
 

jwelectric

Senior Member
Location
North Carolina
Re: 200 amp service

Welcome to the forum. We need to go to 408 to find the answer to your question and to help clear up the answer given by Torcho.

In 408.30 we learn:
408.30 General. All panelboards shall have a rating not less than the minimum feeder capacity required for the load calculated in accordance with Article 220.
Here we were told that the panelboard shall have a rating as was calculated just as Torcho has pointed out. The size of branch circuits and their overcurrent protection will be based on the calculated size of their individual loads and it is not uncommon for these to add up to be a lot more that the feeder circuit and the feeder overcurrent protective device.

As to the limit to 42 circuits in a panelboard here we need to look at 408.35:
408.35 Number of Overcurrent Devices on One Panelboard.
Not more than 42 overcurrent devices (other than those provided for in the mains) of a lighting and appliance branch-circuit panelboard shall be installed in any one cabinet or cutout box.
This limit to 42 overcurrent device rule is for lighting and appliance branch-circuit panelboard ONLY and will not apply to a power panelboard.

For clarification between a power panelboard and a lighting and appliance branch-circuit panelboard see 408.34
 

lady sparks lover

Senior Member
Re: 200 amp service

Yes, this has to do with the load on the panel adding up to 200, not 20 amp breakers. Remember not all circuits maybe on, especially with receptacle loads.


Lady :)
 

bphgravity

Senior Member
Location
Florida
Re: 200 amp service

A typical 200A service in a typical 4 family dwelling is loaded to around 75A at any given time. The calculated load as required by Article 220, even with all the permitted demand factors, is not a true representation of typical loading.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: 200 amp service

Originally posted by beardog:Is there a code on the total circuit-breaker amperage.
You have confused me a little, given that the title of the thread uses the word "service," and given wording of the question. Your profile describes you as a "machinery controls designer," and you are asking about overloading a "service." That word relates to the main panel at a home or office or industrial building, and not to any panel that might be associated with a machine.

I am putting a temporary hold on this thread. I am taking this action because the thread appears to me to be an attempt by a Do It Yourself person to obtain "how-to" information. I hereby invite the Original Poster to send me a Private Message, to explain the circumstances, and to let me know if I have misjudged the circumstances. If you do not know how to sent a PM, then check out the FAQ thread at the top of the list of topics.

And by the way,
Can you assume that it's not over loaded if it never trips the main breaker?
No you cannot. Can you assume that it is safe to back out of your driveway blindfolded, if you have done it every day for a month, and it has never resulted in an accident?
 
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