100 ft to Garage

[hapbob]

I have a detached garage 100ft from house. For past 20 years it has been fed with 10-2 and 20 Amp circuit breaker in house to a panel in garage with 3 breakers of 20 and 15 breakers. I can count on two hands how many time I have tripped the breaker in 20 years. No heavy use here just lights and a heater fan, light use air compressor and hand tools for one man shop. I have now added on a 24x44 addition to this detached garage. I am concerned I don't have enough power now. Can I put a 30 amp breaker in house on that 10-2 wire under ground and just have a bit more juice which I want to see if it is enough by using it? I am looking for advice and opinions on this topic and experience you may have had with similar set up?

Thanks
Hap

 

[TheEquineFencer]

Everyone is going to want to know what loads you plan to run on it. At a minimum, I'd run a new circuit with 120/240 and two 20a circuits, one for lighting and one for receptacles.

Off the top of my head I'd say run a 100A circuit/sub-panel, in the right size wire for the run and you should be able to run anything a "normal" person, keep in mind this is GJ ,would need for your new area. Even if you do not need it, if/when you sell the place and move into a rest home, it'll help the resell value.

 

[Slowgsr]

Sure you could put a 30a breaker on it, but voltage drop will be less then ideal. This is the answer your looking for since you didn't ask for other options

 

[alfredeneuman]

You can't use 15 or 20 amp receptacles protected with a 30 amp breaker.

It's also not allowed to use a 30 amp lighting circuit in a residential setting.

 

[joe_padavano]

You can't use 15 or 20 amp receptacles protected with a 30 amp breaker.

It's also not allowed to use a 30 amp lighting circuit in a residential setting.

Go re-read his first post. The 30A breaker in the house would feed "a panel in garage with 3 breakers of 20 and 15 breakers."

Yes it can be done and yes you will have unacceptable voltage drop in the 10-2.

 

[alfredeneuman]

I shall properly repent for missing that

 

[jacobsed]

Use the 30 amp and see how it goes. I had the same situation and it ended up that for my use it was fine. In a one man shop you can only use so much at once!! haha

 

[alfredeneuman]

The maximum acceptable voltage drop generally recognized is 3%.

A 15 amp load of 100' at 120 volts is exactly that.

 

[LX-Markham]

You just spent the money on a 24x44 addition to the garage, and didn't spring for a new 100A panel? It's really not a huge expense, I would just do it right and have an electrician run a new service.


Edit: LOL @ username alfredeneuman! Awesome!

 

[hapbob]

Ok
I hear ya all
A new service is ideal
But if I can get by with 30 amp feeding panel in garage with 20 and 15 breakers
I want to for now.
Now this is a newbie questions so be kind
If there is a tad to much voltage drop what will,happen ?
What will I notice ?
Thanks
Hap

 

[jacobsed]

I doubt you'll have any meaningful drop over 100ft. What you might experience is not enough amps. I had one motor for a car lift that I needed to rewire as 220. More voltage = less amps. Do you have any 110 motors drawing significant amps?

Ok
I hear ya all
A new service is ideal
But if I can get by with 30 amp feeding panel in garage with 20 and 15 breakers
I want to for now.
Now this is a newbie questions so be kind
If there is a tad to much voltage drop what will,happen ?
What will I notice ?
Thanks
Hap

 

[hapbob]

I have lights
Heater fan motor
Outlets for hand saw/ drills ect
Drill charger
Garage door opener
Radio
Compressor used 10 times a year for 10 minutes each

It all has run off 20 amp for 20 years

I don't know whT to do
At this point. I should put in a 100 amp service but do I really need it ?

Hap

 

[UpstateNY]

You have lights now, how many watts per fixture and how many are on at the same time ?

As regards the 24x44 addition, how many lights have you added that will be turned on coincidentally with the existing lights and what type are the new lights i.e. how many watts per light fixture, both new and old. With that info, and a wee bit of math, it can be determined if you will have a problem. BTW, look at the nameplate of the air compressor, does it say the voltage and amps, that info would help as well.

 

[hapbob]

Ok
Thanks for inputs
I have to figure out I'm going to do in this new addition.
I'm going to just let it go for now,and,if I need to up amp then I will get an electrician dude to help me.

Thanks
Hap