mobile home feeder ?

[pmalavolti]

i have a 135 foot run from my breaker box to my shop. i am going to run it 2 1/2 conduit. my shop box is a homeline 125 20 circuit breaker box. my electrician/buddy said i need #3 copper between the 2 boxes. w/ #6 ground. could a 2-2-2-4 aluminum mobile home feeder replace that.

 

[wyliesdiesels]

Depends on what size feeder youre trying to get. What equipment do u have?

#3 CU is good for 100a and #2 AL is good for 90a. If youre gonna use a 90a breaker in your main panel, then #2 MHF would be fine. Voltage drop shouldnt be an issue...

 

[sberry]

Just as a note. Over the last , hard to believe it is 30+ yrs but have done a couple dozen or so, a couple used as shops to some extent, more like garages with an air comp but have never put a breaker larger than a 60 on one and never heard of a trip from them.
I would say if you were welding regular with a 50A machine and a full 5 hp comp on the line the larger breaker may come in to play.

 

[sberry]

I just did an upgrade on a residential small home and replace a 100 with another 100. The equipment was old but this is a neighborhood and the line feeds other homes, about 500 ft of 2 from the kettle at least.
Even if one did put larger hardware on it wasn't going to mean much and if a place soes have sturdy service you will never know the number 2 in in the line. I have ran at least a dozen in excess of 200 ft.
One time ran a welding shop from a number 2 at 225 ft on a 60 for a winter. We would simply stop welding or didn't weld if the air comp was on It was only 3 hp which helped some. But it all worked, never had to stop due to noticeable power problem.

 

[pmalavolti]

Depends on what size feeder youre trying to get. What equipment do u have?

#3 CU is good for 100a and #2 AL is good for 90a. If youre gonna use a 90a breaker in your main panel, then #2 MHF would be fine. Voltage drop shouldnt be an issue...

planning for a compressor, welder, table saw, eventually a car lift.

 

[wyliesdiesels]

planning for a compressor, welder, table saw, eventually a car lift.

One man shop? If so u should be fine with 90a and MHF!

 

[pmalavolti]

what size aluminum will i need for 125a in conduit

 

[AndyCBR]

what size aluminum will i need for 125a in conduit

1/0 AL can be protected with a 125A breaker and rated for a 120A load under the 75C column. Size the neutral appropriately (typically #2).

Check which cycle of the NEC you are on and make sure it is compliant.

 

[Norcal]

There is a price jump between 100A and 125A circuit breakers, doubtful that there is the load to require 125A + the OP's panel may or may not be listed to accept a 125A breaker. Only the label in the panel can confirm it.

 

[Charles (in GA)]

MHF is direct burial and if the soil is fairly free of rocks, then conduit would only be needed from the trench up and into buildings. If soil is rocky, then conduit all the way is a good idea.

 

[Speedy Petey]

The jump in price from a 90A feeder to a 125A feeder is not worth it in the slightest IMO.

Also, WHY 2-1/2" conduit??? Again, a big cost difference, harder to work with and completely unnecessary. 1-1/2" would be fine. Even 2" will be easier and cheaper.

 

[wyliesdiesels]

OP u havent told us about your loads and equipment!

 

[pmalavolti]

typical garage stuff. compressor, a couple window a/c units, welder, table saw. those are the big items now. hope to add a lift. where mine is a little different is i want to add a home theater in the loft.

 

[theoldwizard1]

typical garage stuff. compressor, a couple window a/c units, welder, table saw. those are the big items now. hope to add a lift. where mine is a little different is i want to add a home theater in the loft.

Remember, you can always turn off you A/C units for the 10-15 minutes you are running your welder or table saw, if you need to.

For a hobby shop, the biggest load is usually a plasma cutter, becuase you ned to run your compressor at the same time. Of course, 2 people working at the same time ...

 

[wyliesdiesels]

U should be fine with a 90a feed and MHF!

 

[pmalavolti]

i forgot to mention a plasma cutter. what size aluminum for 125a at 135 feet run in conduit.

 

[pattenp]

2/0 Al for 125A

 

[wyliesdiesels]

http://www.homedepot.com/p/Southwir...ice-Entry-Electrical-Cable-28713601/202316460