6 swipe main shut off - overload code?

[d64b2024]

Good afternoon - we're considering adding an additional breaker to our "main service panel" which is where the meter is located. That panel has 6 slots (I guess 12) with 5 double breakers currently. One breaker is 90 amps which feeds our interior panel which has lights, cook top, A/C condensing unit, receptacles, etc - the other 4 are A/C heater (50), pump (20), water heater (30), and double oven (50). There is no master breaker or main service disconnect other than these 5 current breakers on the 200 amp service. The breakers add up to 240 amps - so if they all peaked is there an issue or does an 80% rule follow or does new (current) code allow for this? I looked at a new construction across the street and it had 210 amps worth of breakers and it's brand new. My question is can we add another interior sub panel and occupy the 6th breaker with a 60 or 80 amp breaker (taking the total to 300 or 320 amps)? What is the max amps these breakers can add up to? Is there a requirement in the code? As mentioned it seems as though new construction is going beyond the 200 amp service but I don't know if the acceptable rule is a certain percentage or they're doing a load calc on all the devices, etc.... any help is appreciated!

 

[Megawatt]

Good afternoon - we're considering adding an additional breaker to our "main service panel" which is where the meter is located. That panel has 6 slots (I guess 12) with 5 double breakers currently. One breaker is 90 amps which feeds our interior panel which has lights, cook top, A/C condensing unit, receptacles, etc - the other 4 are A/C heater (50), pump (20), water heater (30), and double oven (50). There is no master breaker or main service disconnect other than these 5 current breakers on the 200 amp service. The breakers add up to 240 amps - so if they all peaked is there an issue or does an 80% rule follow or does new (current) code allow for this? I looked at a new construction across the street and it had 210 amps worth of breakers and it's brand new. My question is can we add another interior sub panel and occupy the 6th breaker with a 60 or 80 amp breaker (taking the total to 300 or 320 amps)? What is the max amps these breakers can add up to? Is there a requirement in the code? As mentioned it seems as though new construction is going beyond the 200 amp service but I don't know if the acceptable rule is a certain percentage or they're doing a load calc on all the devices, etc.... any help is appreciated!

To start with you have to understand that you are looking at 2 different calculations with the first one being your calculated load which is the size of the breaker and the second is your actual connected load. Having said that all the breakers you named are probably not being used at the same time. Examples are your heat, double stove, water heater etc. yes you could add a sub panel and to answer your other question is that you are required to have a main breaker outside for the fire department to cut all power off in case of a fire.