How much load can I put on a 200 Amp Panel according to the NEC???
2006-09-13 08:57:21 · 5 answers · asked by alex_blanding2001 1 in Science & Mathematics ➔ Engineering
Yet again people answer the question without any clue what they are talking about. There are several places in the NEC that have an 80% rule. These are about specific loads, and once you add them together it can go to 200A (or whatever the breaker rating is). Frankly, load calculations and figuring out what size wire and breaker to use for things is fairly complicated and not really for a DIYer. For small circuits, there is a rule for 15A max for 14 AWG wire, 20A for 12AWG, and 30A for 10AWG, that tends to make those common. There are exceptions to that. My point is knowledge of the NEC takes time and I'm not going to educate you on the issues involved in this answer.
A couple of the 80% rules (or 125%, depending on which way you think about it). A "continuous" load (which is defined by the NEC as being on 3 hours or more continuously) must be treated as 125% of the the current generally. Electric heat and an electric water heater are specific things in the code that must be treated this way. Another is for motor loads, the load must be 125% the FLA (full load amps) of the motor. Motors have allowances for larger breakers which make them more complicated.
Now, if you think you may be exceeding 160A on your panel, I would suggest getting an electrician to figure it out.
2006-09-14 02:35:09 · answer #1 · answered by An electrical engineer 5 · 1⤊ 1⤋
80% load is intended to provide some margin for error or misuse (think overloading). Also 80% is a good rule of thumb to make allowances for peak loading, particularly in industrial or commercial situations. During morning start-ups, if all the machines are started at once, it would be very possible for peak demand to exceed the maximum. This should trip the breaker, but could result in damage to the equipment.
I do not believe that it is part of the code per se. A panel rated at 200 Amps can handle 200 Amps. However, a good designer has to anticipate the unexpected. Perhaps some minor future expansion. Perhaps someone tries to draw 210 Amps.
2006-09-13 14:30:11 · answer #2 · answered by Mack Man 5 · 0⤊ 1⤋
Where do you get these 80% from, I cannot find any reference mentioning it...?
A 200 Amp panel is supposed to support 200 Amp of (max.) load. That only would change if - instead of 50/60Hz - you run something with a much higher frequency, say 3kHz, then you can only run 180 Amp., because the "rms" value goes up with frequency.
2006-09-13 13:02:41 · answer #3 · answered by Marianna 6 · 0⤊ 1⤋
Normally in the electrical design, If our design is 200A Panel, then, all our maximum loading shall be 75% to safeguard ourself as per the reasons below :
1. that any motor, or air cond running would not trip the system
2. Owner will generally will add in somemore machine to your PANEL in future.
75% of 200A and assume is a 3 phase supply.. you need to use the following formula
75% of 200A = 150A
Power will be 150A x 415 x 1.732 x 0.85
Hope this help
2006-09-13 15:05:02 · answer #4 · answered by Mr. Logic 3 · 1⤊ 1⤋
What's the Code reference for this 80% rule?
2015-05-13 09:55:31 · answer #5 · answered by Nick 1 · 0⤊ 0⤋