Yet another 'power my garage' thread

[Rickenbackerman]

I have a 24x36 detached three car garage. Currently the only juice running to it is a 15A breaker in the main house panel and a hunk of romex buried about 2" deep going out to the garage. All the lights and outlets are run off of this one circuit. I'm SURE there is a huge voltage drop, as the lights (currently only four fluorescent fixtures) have a hard time turning on and there's barely enough juice to start my 5hp compressor.

I want more power! I've done a ton of reading on here, but everybody's situation is a little different, and so is mine. Here are my requirements as far as load goes:
-A window A/C unit
-My lift (pulls 15A on startup)
-5HP compressor (also 15A)
-Lights
-Outlets (and maybe spread this out over two 15A breakers)

and then I'd like:
-2 30A 240V outlets for my mig welder (pulls about 21A)

...so not really all that much, I guess, compared to some of you guys!

I have 150A service in the house. The main panel is FULL. There are even some double-tapped breakers (yeah, I know, but I didn't do it!). And the main panel couldn't possibly be further from the garage. But in the laundry room... which is only about 40' from the garage... there's a subpanel fed by a dual 50A breaker in the main panel. Here's the subpanel:



That dual breaker on the right is 30A 240V and feeds an outlet for an electric dryer. But I have a gas dryer, so it's not being used.

I'm not exactly sure what the three 15A breakers are for (there are actually four, but one is not being used), I think they feed a couple of outlets in the kitchen (and who knows what else). The dual 30A 240V breaker on the left feeds the oven (I think, I'll double check that tonight).

What are my options here? I've got the know-how to install a subpanel in the garage, wire up all the lights and outlets, trench and run wire and all that, but I guess my main question is how to tap into this house subpanel to feed it. I suppose I could repurpose the dryer outlet feed as a garage feed, but that's only 30A. Can I go bigger? I'm not sure what size wire is feeding the subpanel. Can I attach a four wire garage feeder right to the incoming supply of the subpanel somehow or does the feed HAVE to come off of a breaker? That would give me 50A at 240V which I think would be plenty, as long as nobody uses the oven while I'm out there.

And yes, I've seen this picture on here, it should be a sticky!
View media item 16967

 

[wyliesdiesels]

I wouldnt wire a subpanel off of that subpanel with the loads it has and what u plan on running.

No way that compressor is 5HP with a 15a FLA. Its closer to 3HP....

Can your main service panel use tandem breakers?
What brand is it?

And what will the length of the wire be going to the garage?

U will have to abandon the existing feed...

 

[Rickenbackerman]

Logistically speaking, it would be pretty much impossible to come off the main panel. It's in a finished basement and there's no way to run the wire to it. Plus like I said, it's full. I can snap a pic of it later anyway...

Unfortunately, this subpanel is my only option.

And yeah, I know the compressor is really more like 3HP... stupid modern BS HP ratings...

edit: that other dual breaker IS for the oven BTW. It pulls 22.5A.

 

[CNGsaves]

Simply cannot be "impossible" to get a feed from main panel. It has incoming power feed from PoCo . . . so it IS possible to get access !!

Let's SEE PIC's of main panel (cover on and cover off), along with it's general location in house, as compared to where the garage is located.

Might be better to upgrade main panel to 200A and install 90A breaker so you can run MHF aluminum 2-2-2-4 out into 2" conduit buried in yard over to the detached garage. Might as well do it right, rather than "piggy back" a sub on another sub that doesn't have enough juice anyway to add garage.

Next guy to own that house will likely NOT have a natural gas dryer . . . likely electric so he WILL need that 240v breaker for his dryer.

 

[Rickenbackerman]

Not completely impossible, just about 1000X harder. I whipped up a quick sketch of the joint. Totally not to scale. It's a two story rancher BTW. This is the bottom floor. The backside of the house (top in the sketch) is above ground and the front (bottom) is below.



I suppose I could run wire through the crawlspace to the main panel and then trench to the garage. If I had to guess I'd say that run would be about 150 feet, whereas going from the subpanel would only be about 40. I'll snap a couple pics of the main panel here shortly...

 

[Rickenbackerman]

Not very good phone pics, sorry. I don't own a real camera.





Honestly I really don't want to mess with this panel. I see three double tapped breakers, one is a GFI breaker that looks like it has two neutrals going to it? Every single breaker in it is a dual breaker whether it's 120 or 240 and there's no space to add anything. It's ancient and it says it was made by "I-T-E circuit breaker company"?

This house has had no less than four separate additions put on it. They went every which way but up. And the electrical aspect of the joint kinda scares me.

Here's a satellite view of it BTW:

 

[Norcal]

You need a new main panel....

A 1970's I-T-E panel with a hacked up SQ D cover ain't going to cut it, that panel has been out of production for almost 40 years so a new front is not going to be easy.

 

[CNGsaves]

It will help GJ Sparkies to give you best advice, you could determine what size/style wire you have coming in to main panel . . . and . . also what wire is supplying the subpanel in laundry room. Take some close-up PIC's of those wires.

I'm guessing that running bigger wire to laundry room would be daunting task ??

For PoCo incoming power, is that buried or aerial ??

Good luck in figuring this all out. It could get expensive !

 

[94EG8]

It's ancient and it says it was made by "I-T-E circuit breaker company"?

I-T-E got bought out by Siemens a long time ago. Some of the later I-T-E Load Center panels take Siemens breakers, I actually have one, but the one you have looks to be older and it definitely uses different breakers.

 

[Rickenbackerman]

I shot a video with my phone tonight, but it's taking forever to upload. Stay tuned...

 

[Norcal]

I-T-E got bought out by Siemens a long time ago. Some of the later I-T-E Load Center panels take Siemens breakers, I actually have one, but the one you have looks to be older and it definitely uses different breakers.

Siemens is the proper brand of breaker to be used in I-T-E load centers, after Gould Inc. bought I-T-E Imperial Corp in 1976, the breakers were redesigned to what Siemens is using in Siemens and Murray brand load centers today, catalog numbers were changed, a I-T-E 20A single pole EQ frame breaker was a QP1BO120, it's now a Q120, but both are EQ frame.

Siemens bought the I-T-E brand from Gould Inc. in partnership w/ Allis-Chalmers in 1984. (I-T-E Electrical Products Div. of Siemens-Allis, later Siemens I-T-E, the I-T-E brand is no longer used.

Because of companies being bought and sold, it can be a pain to know what fits what.

 

[wyliesdiesels]

Yeah replace that nasty panel before u run power to the garage.

U can use SER inside the crawl space and transition to underground rated cable such as MHF outside...

 

[Rickenbackerman]

When I said "diameter", I meant "width". LOL



I also think I figured out what that other 240V breaker is for. One room upstairs has electric baseboard heat. That must be it.