Transfer switch

[chiefcook]

I have a detached garage that is fed off of the house breaker box with 2 200v 100 amp breaker box.
Can I feed this thru a 30 amp transfer switch as long I don't exceed 30 amps usage at one time?

 

[fantastic]

I think you mean 220/240v & not 200v. Doesn't sound like you're installing any protection to safeguard the transfer switch. Yes, in theory so long as you stay under 30 amps but it sounds like you need transfer switch rated for the 100 amps. Otherwise figure out a way to fuse the 30 amp transfer switch if you proceed.

 

[tblt44]

I thought transfer switches were fore power to generator

 

[Geekhead]

If you have a generator for the garage only, yes a 30A will do. I think you have a 30A feed from your house to the garage and you have a 30A generator for the garage only?

 

[chiefcook]

That is right. The only thing I would use other than lights would be the well pump for emergencies only and only occassionally.

 

[Donald]

Give more details on the 30 amp transfer switch.

Some transfer switches switch 6 or 8 or 10 individual circuits. You switch each circuit from either generator or street power. And feed the transfer switch with the generator.

Then there is the scenario where you push power into the main circuit breaker box with a circuit breaker that can be ON or main circuit breaker ON but not both.

There are main transfer switches where the feed to circuit breaker box is either street power or generator.

And then there are people who feed power into the dryer outlet from a generator and hopefully remember to turn off the main circuit breaker. But that's illegal.

 

[chiefcook]

Give more details on the 30 amp transfer switch.

Some transfer switches switch 6 or 8 or 10 individual circuits. You switch each circuit from either generator or street power. And feed the transfer switch with the generator.

Then there is the scenario where you push power into the main circuit breaker box with a circuit breaker that can be ON or main circuit breaker ON but not both.

There are main transfer switches where the feed to circuit breaker box is either street power or generator.

And then there are people who feed power into the dryer outlet from a generator and hopefully remember to turn off the main circuit breaker. But that's illegal.

The garage is feed from a 220/240 breaker in the main box. That is the only circuit I need the switch for. The house already set up with a 10 individual circuit transfer switch.

 

[Donald]

The garage is feed from a 220/240 breaker in the main box. That is the only circuit I need the switch for. The house already set up with a 10 individual circuit transfer switch.

So unless the 2 circuits that make up the 220V circuit going to garage are 2 of the 10 circuits in the transfer switch the garage will not get any power from generator when it's connected to the 10 circuit transfer switch. The circuits in the 10 circuit switch are often all 20 amp circuits so if the circuit to garage needs to be more than 20 amps it might not work anyway.

 

[chiefcook]

So unless the 2 circuits that make up the 220V circuit going to garage are 2 of the 10 circuits in the transfer switch the garage will not get any power from generator when it's connected to the 10 circuit transfer switch. The circuits in the 10 circuit switch are often all 20 amp circuits so if the circuit to garage needs to be more than 20 amps it might not work anyway.

I understand that. The switch will be only hooked up to the garage with a generator when I need it. Mainly to fill containers from the well in emergencies. The house is on city water.