[ceomat]

I have a question in regards to amps allowed in a breaker box. My breaker box has a label stating that the box has a maximum load of 200 amps, but that it is convertible. I really don't know what the convertible part means. If I look at the breakers installed, these add way more than 200 amps.

These are the breakers that I have installed in the box: Five tandem breakers for 15 amps each (so 5 * 2 15 amps breakers = 150 amps), 4 tandem breakers for 20 amps each (so 4 * 2 20 amps breakers = 160 amps), 1 double pole of 50 amps each (so 1 * 2 50 amps breakers = 100 amps), 1 double pole of 40 amps each (so 1 * 2 40 amps breakers = 80 amps), and 1 double pole of 30 amps each (so 1 * 2 30 amps breakers = 60 amps). If I add them up I come up with 550 amps breakers installed! :eek:

Now these are only installed, but I guess not all the breakers are used to their maximum capacity all at once (example, extra plugs not being used, not all lights on, electric stove, washer and dryer not being used at once, etc).

Now this being said, my question is: Has the number of breakers installed in the box exceeded the box capacity or am I adding the breakers' amps wrong by going with the maximum capacity for each breaker rather than the actual amount of amps being used at once?

Thank you for your advice.

[tkrussell]

The size of a service main is calculated by the connected load as per Article 220 and illustrated by the Examples shown in Annex D of the National Electric Code.

The link to and instructions how to naviagte to the NEC is shown in the Sticky
Note of the this electrcial forum.

Adding the rating of branch circuit breakers is irrelevant, means nothing. And a 2 pole breaker is never added or doubled, a 2 pole 30 amp breaker is only a 30 amp 240 volt circuit.