DIY Home Improvement Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I'm adding a third car attached garage to my house. I want to add a 2 phase 100 amp breaker panel in the garage for a 240 outlet and a number of 110 devices, 5 circuits in all. I would feed a line from the meter box to the breaker panel using 3335 copper wire.
The current meter box only has a single breaker for the 100 amp service to the house. I've searched for a two breaker meter box on-line with no luck. Do they make such an animal? Does the BR type breakers come in a dual 100 amp size and take in the #3 wire? I don't want to make all the runs to the meter box. Thanks.
 

·
Registered
Joined
·
4,469 Posts
You cannot bring more than one power source into your house or garage.
However, you can install a sub panel in your garage if you do a load calculation and determine you have the capacity to do so.

The reason you cannot find it is because its not allowed.
You need to be careful. 100 amp services are fine for many homes. But since you mention this is your third garage, I have a feeling your 100 amp service may not be enough.
You need to do a load calculation.

Edit: If you have a meter main type service with room for expansion this is permitted, provided you have the capacity for 100 amp sub panel. But you cannot have two main breakers going into the house.
 

·
Disrespectful to dirt
Joined
·
1,075 Posts
I'm adding a third car attached garage to my house.
Adding a third space or another garage?

I want to add a 2 phase 100 amp breaker panel in the garage for a 240 outlet and a number of 110 devices, 5 circuits in all.
What are these for? Or more specifically, exactly how much of a load will these have? 100 amps may not be needed.

The current meter box only has a single breaker for the 100 amp service to the house. I've searched for a two breaker meter box on-line with no luck. Do they make such an animal?
No, not in 100 amp class. You would need to use a small meter/load center combination unit.

Does the BR type breakers come in a dual 100 amp size and take in the #3 wire?
Are you asking if a tandem/quad 100 amp BR breaker is available? No.

I don't want to make all the runs to the meter box.
The meter jaws will not have a second set of lugs, nor can you add them. You will need to either add a small breaker panel after the meter/main or a box to make a tap from the main feeder. That's assuming 100 amp service will be enough for what you're planning.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #6
I'm adding an attached garage. The whole house is only 100 amps. I am limited by 100 amps because of the wiring running to the main breakers. The load I'm adding is less than 10 amps.

What I want to do is have two 100 amp breakers. One feeding the original house, then another feeding the garage. I could just rely on the garage breaker panel having one of the 100 amp breakers, but isn't there an option to adding a separate 100 amp service within the meter box protected with a breaker within the same meter box.

This seems like a cleaner solution than splicing into the original feed to the main breakers and adding a new 100 amp breaker in the garage break-out box. Am I missing something?

Thanks guys.
 

·
Registered
Joined
·
4,469 Posts
Sure you can. You may have up to six per service.
My point was you cannot have two separate services entering one structure.

He asked about another main. Not a tap or an extended service.
I understand the 6 handle rule.

If I am missing something by all means share that with me.
 

·
Disrespectful to dirt
Joined
·
1,075 Posts
The load I'm adding is less than 10 amps.
Are you planning to upgrade to 200A service and some point and then charging an electric vehicle?

This seems like a cleaner solution than splicing into the original feed to the main breakers and adding a new 100 amp breaker in the garage break-out box. Am I missing something?
From your earlier post it sounded like you were describing a meter/main combination. That's a single enclosure containing the meter socket and one main breaker, like this (though often the breaker is below the meter:



What you posted above makes me think I was incorrect. Is this presently the setup you have? If not, can you describe your configuration or post a photo?
 

·
Disrespectful to dirt
Joined
·
1,075 Posts
My point was you cannot have two separate services entering one structure.

He asked about another main. Not a tap or an extended service.
I understand the 6 handle rule.

If I am missing something by all means share that with me.
A second main breaker does not constitute an additional service. There is still one service lateral or service drop. That's what is restricted, not the number of main breakers. You may have up to six of those on a single service. It's different from (but related to) the rule regarding up to six service disconnects.

Consider the configuration of a typical residential 320/400A service fed with an underground service lateral. There is a single service lateral which feeds one meter. The output lugs of the meter jaws are typically fitted with dual lugs, either to allow parallel conductors or to feed separate panels. Since 400A panels are obscenely expensive, a pair of 200A panels are used instead. Each of those panels contains a 200A main breaker for use as overcurrent protection and a service disconnect. Each panel connects to one set of lugs on the meter via its own set of service entrance conductors. So you have two main breakers, two disconnects. But it is one service because there is one service lateral. It's the same situation here.

Sorry, I had a much clearer explanation written earlier and Windows decided to crash and destroy it. But I think this makes about as much sense. Or not.
 
1 - 9 of 9 Posts
Top