Beam me up Scotty

[Jim Port]

While that might be handy to help with an IR scan due to the non-typical usage, it does not represent how the service will typically be used or if it is too small. Kind of like adding up all the breaker handle ratings and saying the service is too small.

[Charley L. Bottger]

My understanding and what I have always gone by is its not allowed to exceed 80% of the rating of the panel period. I load the panels up with what is available knowing perfectly well that it would be very unusual for every appliance in the home to be on at the same time but that should make no difference if the appliance are installed the rating of the panel should allow for them all to be on at the same time. Here are a couple images of the panel before I shut the test down once I saw 218 amps the 200 amp main had got up to 115 degrees before I shut down don't know how high it would have got to If had not shut down when I did

[Christopher Currins]

I saw 218 amps at the 200 amp main

Shouldn't this cause the *main* breaker to trip.

[Robert Meier]

Originally Posted by ccurrins

Shouldn't this cause the *main* breaker to trip.

Eventually it will, maybe. That's likely an inverse-time CB which will trip faster based on a larger amount of overload. More overload faster trip. This is based on the manufactures trip curve. For a 10% overload it may take hours to trip.

[Christopher Currins]

Originally Posted by Robert Meier

Eventually it will, maybe. That's likely an inverse-time CB which will trip faster based on a larger amount of overload. More overload faster trip. This is based on the manufactures trip curve. For a 10% overload it may take hours to trip.

Would that be sufficient to protect circuits from overheating? Or normally would individual circuit breakers trip first, or easier?

[Robert Meier]

Originally Posted by ccurrins

Would that be sufficient to protect circuits from overheating? Or normally would individual circuit breakers trip first, or easier?

In general inverse-time CB's are inherently similar. Smaller branch CB's might have slightly different trip curves based on how the manufacturer designs them when comparing them to say the 200 amp main CB in this case.

An example would be to think about an AC unit that runs at 20 amps. Typically the CB protecting that circuit would be rated for about 35 amps. During start up the starting current could be up to 600% of the running current or about 120 amps. That's certainly well above the 35 amp trip setting on the CB but it doesn't trip. That's because it's inverse-time design allows it to pass a large amount of current for a very short duration of time, enough time for the compressor motor to start. If these breaker were not designed this way then large inrush loads such as motors could never start.

[Charley L. Bottger]

Here is a double pole breaker on a free standing cook stove from today that I did not like the temp differential between the two legs should have been close to the same temp on both legs. Putting it on the repair list to have the breaker and or circuit checked

BTW I find a ton of kitchen stove breakers just like this one

[ROBERT V. YOUNG]

Big differential in my opinion.. Nice Mr. Bottger. I have to get a IR camera when my company gets more secure and earnings are dictating upgrades are allowed.
I have looked into pricing and education. Very good findings.
Thanks....... Robert the Canuc.

[Robert Meier]

Originally Posted by cbottger

Here is a double pole breaker on a free standing cook stove from today that I did not like the temp differential between the two legs should have been close to the same temp on both legs. Putting it on the repair list to have the breaker and or circuit checked

BTW I find a ton of kitchen stove breakers just like this one

I agree that they should be closer in temperature if the loads are the same on each leg but what is a normal temperature? Is the lower one normal?

[Charley L. Bottger]

Originally Posted by Robert Meier

I agree that they should be closer in temperature if the loads are the same on each leg but what is a normal temperature? Is the lower one normal?

I generally see the temps range between 100 F and 110F really depends on How long I am operating the stove and the length of run. I pay more attention to the un-balanced temp than how high it is until it reaches up in the area of 130 F and again that will depend on the ambient temp at the panel lots of considerations to take in when scanning panels

[Charley L. Bottger]

Originally Posted by ryoung7

Big differential in my opinion.. Nice Mr. Bottger. I have to get a IR camera when my company gets more secure and earnings are dictating upgrades are allowed.
I have looked into pricing and education. Very good findings.
Thanks....... Robert the Canuc.

Mr Bottger died in 1962 they generally call me Charley