Can I feed 2 100 amp sub panels from my 200 Amp main service?

Answer 1

DO NOT FOLLOW THE INSTRUCTIONS BELOW!

According to this logic, one could chain an infinite number or sub-panels off of a single one hundred amp feed. The second law of thermodynamics prevents this. An hundred amp service is not capable of powering another hundred amp service unless you are trying to move your panel and all of the circuits it feeds as well, without adding another hundred amp load. NEC (National Electrcial Code NFPA Book 72) states that certain loads can be derated but not to this extent.

As far as the voltage drop is concerned, you need only worry about this with runs of about two hundred and twenty five feet or more for a 200 Amp Service running 2/0 2/0 4/0 URD direct burial aluminum.

What you need is a new 200 Amp service to feed your original 100A panel and another hundred amps to feed your new load.

for USA, Canada and countries running a 60 Hertz supply service.Yes you can as long as the feeder to the other 100 amp panel is equal to the ampacity of the breaker. In this case you would need to use a #3 wire rated at 90 degrees C if the distance to the other panel is under 50 feet. If the distance is longer that this a voltage drop calculation would have to be added to increase the wire size.

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My experience would lead me to believe that you could not install a breaker that was greater to or equal to the rating of the main breaker. To add a sub-panel, you will need to install a breaker that is half or lower than the main breaker.

In your case, you have a 100A service; you will need to install a 50A or smaller breaker to service the sub panel.

Consult an electrician if in doubt.

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Answer 2

Yes, you can feed two 100 amp sub panels from a 200 amp main service panel, as long as the total load does not exceed the capacity of the main panel. Make sure to properly size the conductors and breakers to match the amperage of the sub panels and adhere to all local electrical codes and regulations. It's always a good idea to consult with a licensed electrician for proper installation.

Answer 3

You can but your still only going to get 100 amps total between the two panels. Just because it is a 100 amps sub panel does not mean you have to feed it with 100 amps. Figure out how many amps you'll need at the sub and you may only need to feed it with 50 or 60 amps.

Answer 4

If you mean can he amps of each breaker in a panel add up to more than the rating of the panel then the answer is yes. In a panel design the electrician takes into account that each circuit will never be at its full capacity all the time. If each breaker was maxed out to just below its rated current and didn't trip, then the main breaker would trip if its rating was exceeded. This is highly unlikely with proper sizing of mains and individual breakers under normal circumstances.

Answer 5

The electrical code states the the minimum size conductors for a 200 amp service to be 3/0 copper or 4/0 aluminum. 4/0 aluminum is rated at 185 amps but the code allows for use of this wire if the insulation factor of the wire is 90 degrees C. This also allows the aluminum wire to be pulled into a 2" service stack.

Answer 6

What you are looking at is a two pole 100 amp breaker. Distribution panels in North America are designed to use 120/240 volts. Any two adjacent breakers will give you a 240 volt circuit and either leg to the neutral will give you 120 volts.

On the main breaker of a panel the number stated on the breaker is the amount of amperage that the breaker will allow to pass before tripping regardless of which leg the current passes through.

A 200 amp service will have a two pole main breaker with a rating stating its capacity of 200 amps.

Wire size into the breaker will give you a good clue as 100 amp breakers will use a #3 conductor whereas a 200 amp breaker will be fed with a 3/0 conductor.

Answer 7

No it does not mean you have a 200 amp service. you should / could possibly have a "main" breaker. That breaker size is your service size.

Answer 8

Yes. Five 20 amp breakers would be 100 amps. It doesn't work that way. The load placed on this box at any given time cannot exceed 100 amps. You can put as many breakers as it will hold.

Answer 9

Your main breaker cannot exceed the rating of your panel.

Answer 10

Yes, run 4 AWG copper between the panels protected by a 100 amp breaker.