Routing to detached

[jpcjguy]

Hi all,

So I am in the planning stages of a detached garage with lift - approx 32 wide x30 deep.
Here is the probable location (in red) on the 2 acre property:

My challenge is getting electrical there. My panels are in the garage which is on a slab. The wiring for the house goes "up". Above the garage is the master bath with the sloped roof (9/12 pitch). I could go up into the crawl area that is not used (back of master closet)

, then feed up into the attic from there

and then across the attic and down 2 stories to the corner of the house in the crawlspace and then underground to the garage.

What a PITA. Not to mention the length of wire to go up, down (turn around - ) and then the 150' to the garage. Sheesh.

As you can see the electrical box is in the worst place possible also for running new service directly to the garage.
If I try to go outside right away, I am under the driveway in the back and a paver patio/walkway that runs the whole length of the house.

Any other ideas? I would imagine the size of the wire I would need for 100A service out there for the lift, welder, compressor would be huge considering the length also.
I can do all the wire fishing myself and have my electrician friend do a final review before inspection.

thanks
Joe

 

[Charles (in GA)]

Are you on septic system? Where is the tank and field located? I would exit the garage out the back and tear up the pavers to get past them. Running thru the attic is a lot of time and energy and money, and you end up with a cable that may have to be derated due to extreme temperature considerations in the summer.

Personally I would move the garage closer. Thats a long walk. The further you have to walk and out in the weather, the less inclined you are to go out there.

 

[jpcjguy]

The septic is where the words "trench for electrical" are. I guess a slight bend in the yellow line would be more accurate. I have thought of bringing the garage up so it is more in line with the house - will also benefit from shorter driveway from the street!

 

[pattenp]

Short of messing up hardscape you are limited to going through the house. You are looking at needing to use 2/0 aluminum to get the amps you want at that distance.

 

[CNGsaves]

I'd skip the idea of trying to go through house in your situation. You're trenching very long run anyway, might as well keep in simple and just have one long run all trenched.

Your sewer leech field is a problem no matter how you go. Your route seems to cross over leech field which is No No for sure.

See attached proposed route (in blue) that would go towards property line that has the trees, then directly to the garage. Hopefully, this route won't have problem with the leech field. See best guess I have for your your LEECH FIELD (LF shown in purple in drawing) based on your previous threads on garage location.

Sparky's will chime in with specific details, but you might be able to get 60A or 70A with Aluminum 2-2-2-4 MHF (mobile home feeder) that is direct bury. Your distances will be farther with my dogleg route. However, at only $1.47/ft the AL MHF is absolute bargain compared to any other option.

 

[jpcjguy]

I'd skip the idea of trying to go through house in your situation. You're trenching very long run anyway, might as well keep in simple and just have one long run all trenched.

Your sewer leech field is a problem no matter how you go. Your route seems to cross over leech field which is No No for sure.

See attached proposed route (in blue) that would go towards property line that has the trees, then directly to the garage. Hopefully, this route won't have problem with the leech field. See best guess I have for your your LEECH FIELD (LF shown in purple in drawing) based on your previous threads on garage location.

Sparky's will chime in with specific details, but you might be able to get 60A or 70A with Aluminum 2-2-2-4 MHF (mobile home feeder) that is direct bury. Your distances will be farther with my dogleg route. However, at only $1.47/ft the AL MHF is absolute bargain compared to any other option.

Thanks CNGSaves for taking the time for a great response! That is definitely an option.
Thinking about it, if I go underground right out of the garage, I could theoretically go back under the house in the crawlspace and avoid taking up a ton of pavers. I would only have to go under a 3' wide walkway in front of a side door. In the pic below, the yellow is in the ground, then the orange is in the crawspace before the red being underground again to the garage. (Ignore the red and blue lines higher on the house - I am recycling this pic!)

Here is another route around the septic - the blue line (part underground, part in crawspace and then underground again to the garage).

 

[CNGsaves]

You're route is better anyway as I forgot that you might want swimming pool in the area I went through with my dogleg route. Scratch my route unless you want Electrified Swimming !!!

Sparky's will have to tell you code for running that through crawlspace in one long continuous service cable to detached garaage. Likely needs to be inside conduit once cable starts coming out of ground and through the crawlspace.

What is realistic Amps you NEED in that detached garage?? Often realistic power of 50 or 60A would be plenty. What all will be electric in detached??

 

[jpcjguy]

You're route is better anyway as I forgot that you might want swimming pool in the area I went through with my dogleg route. Scratch my route unless you want Electrified Swimming !!!

Sparky's will have to tell you code for running that through crawlspace in one long continuous service cable to detached garaage. Likely needs to be inside conduit once cable starts coming out of ground and through the crawlspace.

What is realistic Amps you NEED in that detached garage?? Often realistic power of 50 or 60A would be plenty. What all will be electric in detached??

The pool is scratched. Too much liability, not as desirable for resale (always have to think about it, even though we have no plans of going anywhere), and the garage will probably drain me completely of $$. The kids can go to a neighbors or the YMCA - ha!
As for Amps necssary - figure on a 10K lift in there, I have a millermatic 252 welder, 60 gal compressor - which I will probably upgrade to better keep up with my sandblasting cabinet (nothing fancy - the harbor freight one). I have Jeep CJs that I work on and go wheeling with. Figure on lights, music, fridge. Usually just me working (twin boys are almost 5, but not ready for power tools yet!) but sometimes some buddies - grinding, welding, etc.
Eventually a mini split for heat and cooling....

 

[jpcjguy]

oh - and another question for everyone. If I do go with an electrical route that I end up branching off the corner of the house ( in the 2-3' crawlspace), would it be possible to have a junction box there? Basically, if my garage is a ways down the road, I could at least run the line (not hooked up in the main electrical panel) to that corner of the house (conduit under the house) and when the time comes to trench to wherever I end up with the garage, I only have to go in the crawlspace and connect the two wires.
Not sure if code allows this - but could be something I do ahead of time.
Just curious...

 

[pattenp]

I'd wait and pull the wire as one piece. You can do the conduit from the panel to the end of the house. You are going to need large wire for the feeder and doing a splice is going to require a very large and $$ junction box.

Also when you threw the mini split HVAC into the mix that bumps up your amp needs.

 

[jpcjguy]

I'd wait and pull the wire as one piece. You can do the conduit from the panel to the end of the house. You are going to need large wire for the feeder and doing a splice is going to require a very large and $$ junction box.

Also when you threw the mini split HVAC into the mix that bumps up your amp needs.

Good point - splices are not too bad:
http://www.amazon.com/NSI-Industries-ESGS-4-Easy-Splice-Connector/dp/B008KMKESI

Boxes could get expensive - not sure on the size I would need.

 

[Aceman]

You're getting the cart before the horse.

Load calc the house, load calc the future garage. See if the existing house service can even carry the load. You may need a service upgrade.

Also, call your power company and ask what it would cost to install a second meter fed from your existing padmount transformer.

 

[Bruce&Jean]

I went with the second meter option and am so glad I did. In the long run it was cheaper and much easier. Now my 20 X 30 X 10 shop has its own 200 amp service.

 

[jpcjguy]

I went with the second meter option and am so glad I did. In the long run it was cheaper and much easier. Now my 20 X 30 X 10 shop has its own 200 amp service.

I will have to check with them. If I recall, I have to pay to run the line - and it would be probably 300ft from the green box.