Load capacity of 200-amp panel (2024 Update)

[Ralph_n]

And dont forget some heavy loads such as an electric water heater, any electric heating or cooling devices, electric range (if these is living space in this same building), etc.

The existing 200A breaker box does not necessaily need to be replaced, they could add a secondary box, such as a 100A box, which could be used to power the new bed, as well as all the other stuff like lighting and so on. That may or may not require a separate service entrance and maybe a second meter. Also the pole transformer may need to be upgraded.

Something like this, really needs a licensed electrician to look over, and determine the best solution.

I do question how often the OP actually uses all these beds at the same time??? But I dont know anything about this sort of business. (I'm glad I dont have to pay the electric bill though)....

[trader_4]

All you need to know is that having all the lights go out at a business like that doesn't have to happen often to be big trouble. But I did suggest getting the breaker trip curve, so he can get an idea of how long he could be at 225A before it trips.

[gfretwell]

Why would a 200a breaker ever trip with 195a?

[gfretwell]

He won't get a second meter but they could set a gutter on the load side of the meter, tap off another 100a and rock on. Then the PoCo would have to come up with a 320a meter and heavy up the service cables and heavy up the transformer if necessary. The owner puts in the SE cable from the service point to the gutter. That will also trigger another ground electrode conductor from the new panel.

[Ralph_n]

I know a lot about electrical, but you lost me on the "gutter" thing. Can you either explain or provide a URL to some photos.

[trader_4]

Here's an example of what they look like:

It's essentially a rectangular metal box where you can bring the service in, then wire it over to two or more panels. They do that here for big houses that have a 300A service, for example. Put the gutter in between two 150A panels.

Gfre was suggesting that the OP could add a second panel that way and it's probably the most cost effective way, assuming the existing can't go over 200A.

[Ralph_n]

OK, Thanks... I've seen those in use on some commercial buildings. I never knew what they were called though...

[Ralph Mowery]

Several reasons. It could be old and tripped several times and gotten weak, if in a very hot place, due to the tollorance when it was made. Most breakers for the home work on heat. It just depends on how long it takes to heat up. If in a very hot place it may trip after a week or so if it has slightly below the rated current through it, or it may never trip if in a cool place and has slightly more than the rated current.

[clare]

After a long time at full load, if the ambient temperature increases, it CAN trip below the rated current. Since all of the breakers contain thermal trip mechanisms, they do produce heat - so if the box cannot shed the extra heat, it will get warm. If it gets warm enough the main breaker is de-rated.

All of the breakers are supposed to be de-rated to 80% for continuous load - so a 30 amp breaker should not be loaded above about 25 amps continuous load.

I know there is a lot of conroversy over the 125% load calculation (which is effectively an 80% load limit) - but if he is loading every breaker to 100% of it's rated protection current, and the total current ratings of the breakers in use = 100% of the main breaker rating, he's REALLY pushing things. If he has a 100% load rated main breaker in a 100% rated enclosure, the extra heat is being dissipated and accounted for - but you can be pretty well assured he does NOT have a 100% rated enclosure and the panel is likely inside a closet where it does not shed heat effectively.

[trader_4]

I believe they actually work on both heat and magnetically. Heat is the tripping mechanism for loads that exceed the limit by a modest amount. Magnetically, they trip in milliseconds from a severe overload.

It just depends on how long it

I tend to doubt that it's going to take a week to trip. Whatever final temp the breaker winds up at, it's going to get there in a few hours. If it doesn't trip then, seems unlikely it's going to trip a week later, unless the ambient temp increases.

[Tony944]

----------------------------- Current total amp draw from beds = 190 amp draw Everything works fine with this configuration but I want to REMOVE a 20amp draw bed and replace it with a 55amp draw bed, which will make the new amp draw 225amps at any point where all 6 beds happen to be turned on at the same time. Just find it hard to believe that my only option would be to have the city re run a total new service over 25 amps. Can this be done and if so can it be done safely?

First of all you need to check your supply source flocculation, a voltage if flocculate and amperage with reliable accurate instruments. Do not forget that some lamps can use more power then the other, Incandescent, Florescent, Mercury, ETC. It should not be a much difference but you should know it sense you are having problems, check with manufacture. You also have current differences on different beds, you need to check that all phases are properly load balanced!!! You have being giving many Ideas and all circuit breakers operate putty close same unless are design for Motors safety which can be fix time or in some cases even ?Variable?. Fix rating usual load should not exceed more then 90% of it?s settings for reliable operation. In any case you should have fast blow fuses for your lamps individually and not circuit breakers.

[whitestonervholdings]

How many 50A, 120 Volt receptacles can be on a 200 amp 120/208V 3 phase panel per code??

[gfretwell]

It is not about "receptacles", it is about calculated load. What are you plugging in? The simple answer would be 12 (4 per phase) but that is not really a code driven answer.

[philo]

LOOK AT THE DATE

[gfretwell]

The last question was simply tacked on to a 10 year old thread. It was posted today

[Ralph Mowery]

Are there any 50 amp receptacles even made for 120 volts ?

If so , there is probably not a limit on the number.

[James Wilkinson Sword]

Fuck the code, use maths.

[Tony944]

Are there any 50 amp receptacles even made for 120 volts ?

If so , there is probably not a limit on the number.

Yes 60 amp. #HBL-360R4W and 100 Amp. #HBL-3100R4W

[gfretwell]

Nema 5-50

[Ralph Mowery]

Must be some really special loads to draw that much power on a 120 volt circuit.

Guess that I was thinking about a more normal home.