Incoming service amperage?

BlackWidowZ71 · Oct 13, 2020

Basic question..jist trying to gain some knowledge.
I have 2 breaker boxes in my home. Each have 100 amp main breakers.
One is not a sub to the other. Both are serviced directly from the meter outside.
Should I assume that my house has a 200 amp service coming in? Just split between the 2 boxes? Upstsirs box primarily operates items on that floor, and 2nd box does same for basement.
Thank you in advance for replies.

littlespark · Oct 13, 2020

There’s normally a service fuse BEFORE the meter. That will dictate the total load.
It could be 100A or more likely 80. Possibly only 60.
A 100A mainswitch in a consumer unit is just a rating. It can cope with 100A safely. It’s not a circuit breaker that would trip out at 100A.
I’ve just read you’re in Baltimore, so things might be different than UK.
One of our American members might help

BlackWidowZ71 · Oct 13, 2020

littlespark said:
There’s normally a service fuse BEFORE the meter. That will dictate the total load.
It could be 100A or more likely 80. Possibly only 60.
A 100A mainswitch in a consumer unit is just a rating. It can cope with 100A safely. It’s not a circuit breaker that would trip out at 100A.
I’ve just read you’re in Baltimore, so things might be different than UK.
One of our American members might help

Thank you for reply!. I didnt even think about the US/UK thing. But overall what you're saying makes sense.

Megawatt · Oct 13, 2020

BlackWidowZ71 said:
Basic question..jist trying to gain some knowledge.
I have 2 breaker boxes in my home. Each have 100 amp main breakers.
One is not a sub to the other. Both are serviced directly from the meter outside.
Should I assume that my house has a 200 amp service coming in? Just split between the 2 boxes? Upstsirs box primarily operates items on that floor, and 2nd box does same for basement.
Thank you in advance for replies.

BlackwidowZ71 I hate to tell you this but I can tell you what you have without looking at it. It sounds like You have a 100 amp panel located outside , you also have another 100 amp panel being sub fed inside your house from your main panel. I’ve never seen the power company or the inspector let you split bolt 2 separate panels on the load side of the meter without short circuit protection

BlackWidowZ71 · Oct 14, 2020

Megawatt said:
BlackwidowZ71 I hate to tell you this but I can tell you what you have without looking at it. It sounds like You have a 100 amp panel located outside , you also have another 100 amp panel being sub fed inside your house from your main panel. I’ve never seen the power company or the inspector let you split bolt 2 separate panels on the load side of the meter without short circuit protection

Picture attached. I have 2 separate lines from meter to each panel box.

Megawatt · Oct 14, 2020

BlackWidowZ71 said:
Picture attached. I have 2 separate lines from meter to each panel box.

I’m sorry I stand corrected. I’ve never seen a single family dwelling made up like that

BlackWidowZ71 · Oct 14, 2020

Megawatt said:
I’m sorry I stand corrected. I’ve never seen a single family dwelling made up like that

Yes sir, its bizarre. Im not an electrician, but in my 22 years as a fireman..Ive never seen a single residential home like this. My home is split foyer, and when I moved in... there were originally 2 front doors..Im assuming at one point the intent was a basement level area and upstairs seperate. I guess it would be safe to assume that I dont have total 200 amp service to entire home..just 100 amps each for both levels of home.

telectrix · Oct 14, 2020

beginning to sound more logical. could have been 2 separate dwellings in the past, each with it's own supply, but fed by one meter.

BlackWidowZ71 · Oct 14, 2020

telectrix said:
beginning to sound more logical. could have been 2 separate dwellings in the past, each with it's own supply, but fed by one meter.

Thank you for the replies! Yeah, definitely a good guess. At least now I have a baseline of whats going on. Thank you!

Megawatt · Oct 14, 2020

BlackWidowZ71 said:
Yes sir, its bizarre. Im not an electrician, but in my 22 years as a fireman..Ive never seen a single residential home like this. My home is split foyer, and when I moved in... there were originally 2 front doors..Im assuming at one point the intent was a basement level area and upstairs seperate. I guess it would be safe to assume that I dont have total 200 amp service to entire home..just 100 amps each for both levels of home.

I guess you would be 2 separate 100amp boxes. Look on the bright side, you still in theory have 200 amps and a lot of spare spaces to add something