Electrical Panels Rating

Google is your friend.

I bet that Google cannot give an unambiguous answer.

Neither will this forum.

I hope you are not serious.

Read a book.

Shirley you jest....

I'm serial, and stop calling me Shirley!

Okay, Mabel.

What is the color of a blue sky?

• What exactly is the meaning of a 100 amp electrical panel ?

It has bus bars inside that distribute power to branch feeder circuit breakers, and those bus bars are rated for 100A maximum. So your cumulative load fed through the other branch feeder breakers cannot exceed 100A or the bus bar will melt.

Melting bus bars is not good, in case you cannot extrapolate that.

"... cannot exceed 100A or the bus bar will melt"

Exceed by how much? Assuming they're copper and if they melt at, say, 101 amps, is their temperature at 90 amps merely 1500 F? Surely you do not believe the melting of busbars is the actual criterion for this rating. If they were 17 AWG copper wire, yes, but busbars?

I believe he was speaking rhetorically....

Ratings are probably not based on bus bars being close to melting, but rather on something like 40ºC temperature rise.

"Exactly" is difficult.

Usually, it means that the panel can continuously carry a current of 100 amperes rms AC power frequency 50 or 60 Hz at a certain standard rated voltage e.g. 230V and ambient condition, inside a building used by ordinary people for domestic or commercial purposes, in conformity to a national or international standard (which will define permitted conductor/insulation types, temperature rises and insulation thickness etc - all basically to control risk of fire, smoke or electrocution by well-proven means).

"Continuously" usually means a life expectation of about 20 years for building electric power equipment, but typically loading is less than rating and many installations last 50 years.

Of course, the panel might be for 120 volts DC lighting and have a rating in mean current.

Essentially the same panel might come in ventilated or "water spray proof" variants with different ratings. Standard ratings might be 1000 metres maximum altitude above sea level and 40 Celsius ambient but the same panel could be derated for 4000 metres altitude with reduced voltage and current and carry an appropriate rating plate.

You may have to look at the maker's brochure to find to what standards equipment is designed and tested. Industrial equipment will usually have a rating and serial number plate which lists the essential standards

Dear Friend,

Your question is "What exactly is the meaning of a 100 amp electrical panel ?"

It refers to the capacity of the Panel. However the specification should include Fault Current Level, Voltage etc. to be indicated. Refer the drawing for the panel which will describe clearly.

DHAYANANDHAN.S

A 100 amp panel means a panel that contains electrical component(s) which can deliver safe power of 100 amp to its load.

Patrick Whowha