Ask Experts Questions for FREE Help !
Ask
    educateme's Avatar
    educateme Posts: 2, Reputation: 1
    New Member
     
    #1

    Oct 26, 2007, 11:08 PM
    Rewiring garage: under or over ground?
    Hello,

    My home is being rewired (to 100 amp) to eliminate all of the knob and tube wiring. I also need to have my 2 car detached garage rewired. It is approx. 50 ft. from the house. I need lighting and some outlets. It will be used for recharging the mower, a soldering iron, a few power tools, etc. I would like to add a door opener in the future.

    I was first told the wire would have to be 2 ft. deep, then later was told 3 ft. deep. 50 amp service has been suggested w/a breaker box wire running overhead to the garage. I am worried that the children may knock the wire down when playing ball in the yard. I have been reading through your responses and realized there is a lot to all of this, much more than I thought or know anything about: different conduits, wires, sun resistant wires, and so on.

    Questions:
    Is one method better than another?
    Is one more cost effective?
    What materials should be used?
    Is 50 amp sufficient?
    How much should a job like this cost? (I am willing to dig the trench if underground is recommended)

    Thank you for all of your help.

    educateme
    usmcmatt's Avatar
    usmcmatt Posts: 5, Reputation: 1
    New Member
     
    #2

    Oct 27, 2007, 02:31 AM
    Quote Originally Posted by educateme
    Hello,

    My home is being rewired (to 100 amp) to eliminate all of the knob and tube wiring. I also need to have my 2 car detached garage rewired. It is approx. 50 ft. from the house. I need lighting and some outlets. It will be used for recharging the mower, a soldering iron, a few power tools, etc. I would like to add a door opener in the future.

    I was first told the wire would have to be 2 ft. deep, then later was told 3 ft. deep. 50 amp service has been suggested w/a breaker box wire running overhead to the garage. I am worried that the children may knock the wire down when playing ball in the yard. I have been reading through your responses and realized there is a lot to all of this, much more than I thought or know anything about: different conduits, wires, sun resistant wires, and so on.

    Questions:
    Is one method better than another?
    Is one more cost effective?
    What materials should be used?
    Is 50 amp sufficient?
    How much should a job like this cost? (I am willing to dig the trench if underground is recommended)

    Thank you for all of your help.

    educateme
    Underground would be better and safer. The codes are different in different areas of the country. I know in Albany NY the depth is 4'. Here in Modesto,CA, it's only about 1'. It all depends on the frost line. Make sure you use exterior wire, and conduit. I'm not sure of the codes here but you can get the book from the local power company. Most will even have diagrams. Hope this helps a little.
    Matt
    KBC's Avatar
    KBC Posts: 2,550, Reputation: 487
    Ultra Member
     
    #3

    Oct 27, 2007, 03:26 AM
    Also,you can rent a trenching machine to do the digging ,its like a oversized chainsaw and will do the work in no time(electricians and plumbers also have these and would do the job for X $ per foot)

    If you got an electrician to do the work(trenching) you could ask him directly what wire and conduit to use.

    And remember,Always call JULIE before you dig(local utilities company will have their #)
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
    Uber Member
     
    #4

    Oct 27, 2007, 05:49 AM
    Quote Originally Posted by educateme
    Questions:
    Is one method better than another?
    Is one more cost effective?
    What materials should be used?
    Is 50 amp sufficient?
    How much should a job like this cost? (I am willing to dig the trench if underground is recommended)

    educateme
    Each method has it's pros and cons. Underground for a 50 foot run is better for a few reasons, safety and appearance for example. Overhead would be subject to damage, etc for obvious reasons. Ned to keep it at a height that it would not be hit. Exterior conduits would need to be surface mounted on each building up to the height the cable is needed, a min of 10 feet with no vehicle traffic.

    The con to underground is the trench, not impossible, but back breaking unless you rent a trencher. Once the trench is done, then the rest is fairly easy.

    I would use PVC conduit Schedule 40, and associated fittings, which is all typical and very accessible at home remodel stores.

    50 amp seems to be more than sufficient for the loads you mention, with a decent cushion for added load. This would require a 1 " PVC conduit, 3- #6 copper wire with either THHN/THWN or XHHW insulation, and 1- #10 copper green as the equipment ground.

    At each building you would need a elbow to rise up out of the trench and an LB fitting for a hard 90 deg turn into the building. Inside you can change over to cable, using a 4-11/16 in square junction box and cover. At the garage you can continue the conduit directly to the subpanel.

    The minimum depth of conduits is listed in Table 300.5 of the National Electric Code. In your situation the min depth will be 18 inches.

    Any info provided by a utility company may or may not follow code, as they are exempt from building and electric codes. Always consult with local and state codes for any work done, as each city and state, while they all adopt the NEC, do have minor changes and waivers. Some areas, due to soil conditions require a bed of sand above and below buried conduits.

    At the subpanel, be sure to have a separate equipment ground bar for the green wire, and connect only bare and green wires to it. Keep the neutral insulated and isolated by using the neutral bar in the panel and do not use and screw or jumper to bond the neutral bar to the metal can of the panel.
    educateme's Avatar
    educateme Posts: 2, Reputation: 1
    New Member
     
    #5

    Oct 27, 2007, 05:04 PM
    Thank you for the info. I thought that underground would be better also. Do you have an idea of how much this job should cost for an electrician to do?
    I really appreciate all of you and your assistance.

    educateme
    usmcmatt's Avatar
    usmcmatt Posts: 5, Reputation: 1
    New Member
     
    #6

    Oct 27, 2007, 07:29 PM
    If you do it yourself probably around $150-200.00, that's materials and sweat equity. If you Hire a electrician multiply that by maybe 15x's. They don't come cheap. You can probably find a good handyman that would help you for about 10.00 an hour (under the table of course). It really doesn't sound like a big job at all and shouldn't take long at all.
    Good Luck with it. What part of the country are you located? I should have asked before committing to it not being hard.
    labman's Avatar
    labman Posts: 10,580, Reputation: 551
    Uber Member
     
    #7

    Oct 27, 2007, 07:51 PM
    If you hire a handyman, make it clear you are in charge, and follow tkrussell's instructions to a T

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Rewiring the attic [ 1 Answers ]

Im rewiring the attic my ceiling joist are 2by4 do they sell housing for those joist

From Pouring Garage Pad to Construction of Garage [ 4 Answers ]

How long to you have to wait after pouring the cement garage pad before you can begin construction on the garage?

Rewiring an old chandelier [ 2 Answers ]

Good morning, I have been given a really old 7 arm bronze chandelier. The thing is really impressive, it must weigh at least 40lbs! It still has its original wiring; the strands are whitish and the insulation appears to be made of some kind of rubber which crumbles to dust at the slightest...

Open ground when neutral not touching ground [ 3 Answers ]

Hi, I was moving around a room and noticed my wife wanted her desk elsewhere. I decided to, since she would have her computer on it, check the outlet she would be moving to. It seemed old so I changed it. I noticed before I changed it that with my GFCI tester, all sockets on this circuit were...

Rewiring an old phone [ 1 Answers ]

How do wire an old dial-up phone so I can plug it into a regular jack?


View more questions Search