Wiring a Detatched Garage


  #1  
Old 07-14-04, 02:02 PM
CurrierConInc
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Wiring a Detatched Garage

I need some help, this post is going to be long, so please bare with me.

1) I have a Detatched Garage that I'd like to wire with Direct Burial. I'm about 150' away and would like to have 60 AMPs running to it. Should I use a 60 or 70 AMP panel and just run 60 AMP to it? I'm getting my Power from my Main in the house (which would have a 60 AMP breaker)

2) I'm only planning on running a Garage Door, lighting, recepticles and a Compressor on separate Circuits. Should I go with a Breaker Panel or a "Main Lug" type of box?

3) For the 60 AMP service, is 6 AWG 4 conductor wire sufficient? I am told I need a grounding rod from the garage so should I just run 3 conductor?

4) I'd also like to run some data cable and Coax for a TV. I understand they need to be at least 6" away from each other. I'm thinking of running to Cat5's and one Coax. Should I run the 3 of them in PVC conduit or should I buy the direct burial Cat5e ( I believe it's called) and put them in the trench together?

5) Does coax always need to be placed in PVC ?

All of this is going in a place that never will get more than foot traffic. My trench is 18" deep. I think that is all the info I have, Please help that trench looks ugly out there without stuff in it !! Thanks.
 
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Old 07-14-04, 03:10 PM
J
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1) The panel you buy can be rated anywhere between 60 and 6,000,000 amps. Often people buy a higher-rated panel because it has more spaces.

2) Either way. The main breaker (which serves as a disconnect) gives you more flexibility so you can add more circuits later and so you can shut down the garage power more easily.

3) I recommend three insulated conductors plus a grounding wire. In some limited circumstances, the grounding wire can be omitted, but I'd prefer not to explore that unless it's important to you to omit the grounding wire. The grounding rods are necessary in either case, since they serve a completely different purpose.

4) I never go to the extra work of using conduit if I can get away without it, but it's your choice.

5) No. The cable TV company doesn't, so why should you.

If you direct bury the feeder, the trench needs to be 24" deep. If you only go 18", you need conduit for the power feeder.
 
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Old 07-14-04, 08:30 PM
CurrierConInc
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So if I run 6AWG Direct burial on the bottom of my trench at 24", then fill in 6" of sand I can lay CAT 5e and my coax and fill in my trench? No conduit at all ?
 
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Old 07-14-04, 09:16 PM
J
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Almost. You still need conduit from the bottom of the trench up and into the building at each end. But you don't need any conduit in the bottom of the trench.
 
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Old 07-15-04, 06:06 AM
CurrierConInc
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Thats great .. anyone think that running 6 AWG for a 60 AMP service is going to lose too much Amperage over 150' ?
 
  #6  
Old 07-15-04, 06:30 AM
R
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You won't lose any current. The voltage will drop. I get an 8.6 volt drop, or 3.6 percent.
 
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Old 07-15-04, 07:46 AM
J
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And that's the worst possible voltage drop. It only occurs in the rare event that you are actually using the full capacity. 99% of the time, the voltage drop will be much less.
 
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Old 07-15-04, 08:07 AM
CurrierConInc
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And I can just bury the regular old RG6 and Cat 5e 6" above the 6 AWG, without any conduit in the trench? I live in Northern NY and we have rather harsh winters. I just wanna be absolutely sure I understand.
 

Last edited by CurrierConInc; 07-15-04 at 08:32 AM.
  #9  
Old 07-15-04, 10:36 AM
rlrct
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I can't answer the RG6/cat5e question, but don't forget marking tape at least 12" above your shallowest conduit/conductor.
 
  #10  
Old 07-15-04, 11:00 AM
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If you run your communications cable parallel with your electrical feed you may end up with electrical interference in your communications cable. I have been told that you should avoid running communications cable (including coxial cable) within one foot of an electrical cable to avoid interference. When electrical and communcations cables cross it should be at a right angle to minimize interference.

This advice came from a installer of home theaters who advised be of the need to maintain separation for a basment remodel I am working on. The advice makes sense but sometimes audiophiles go to the extreme. I don't know if my eyes or ears are sensitive enough to pick up any interference!

DavidJ
 
  #11  
Old 07-16-04, 06:47 AM
CurrierConInc
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anymore comments?
 
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Old 07-16-04, 07:21 AM
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Electrical wire radiates EM (electromagnetic) energy. An EM field is generated by electrical wiring.

The strength of the field and how far it radiates depend on the size wire, the amount of current and the voltage, the type of insulation, and the medium (air, dirt, clay, rock, etc.).

How that field effects communication wiring depends on the communication signal and it properties (mainly strength and type of signal). Naturally the insulation around the communication wiring also factors in.

My advice is to separate the communication wiring from the electrical wiring by a foot or so. This could be horizontally and/or vertically. And also to use good quality cat-5 and coax cable.
 
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Old 07-16-04, 07:26 AM
J
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It's always a good idea to check to see that whatever you bury is approved for burial by its manufacturer.
 
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Old 07-16-04, 07:11 PM
CurrierConInc
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well, that is the thing John ... I bought some RG6 and some Cat 5e that says that it is for outdoor applications, but is says nothing about buring it. As for the RG6, do they make an actual cable specific for underground?
 
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Old 07-16-04, 07:26 PM
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Outdoor Cat5e is distinctly different from direct burial Cat5e.

Outdoor is usually quite flexible, and much like standard Cat5e. THe jacket is rated for UV resistance however, so it won't break down when exposed.

Direct burial Cat5e has a very thick, stiff sheathing (generally black), and the wires themselves may be in a gel (which provides some protection from frost damage).

Direct burial RG6 is similar, in the the outer insulation is much stiffer and thicker than standard RG6.
 
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Old 07-16-04, 07:31 PM
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Yes, you can buy CAT5e cable for outside use. I canít remember the type, but itís available in Home Depot.

I would not bury the communication cable next to the electrical cable, too much interference (as pointed out by racraft). I would bury the communication cable only 6 inches down. I would not worry about itís longevity, the cable will last longer than the CAT5e standard. By the time the wire needs to be replaced, we will be at CATn (when n is a big number) cabling standard, and coaxial cable will be in the museum!
 
  #17  
Old 07-18-04, 01:02 PM
temarthers
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Wiring a Detached Garage

I would not run the Cat5e underground. I used to work at a college, they were lazy and ran it through Large conduit, all of the other lines were Fiber Connections (No Problem). The one that was underground even in the conduit seemed to be proned to lightening. Every time it stormed lightening, that cable connected to a Cisco Switch would blow the port, we would have to move to another port, finally I talked the into running a Fiber Connection. They come different lenghts. After replacing it, we never had a problem with it. Plus the fiber can be ran with your electrical and not cause a problem, just be careful not to break the Glass inside the fiber.
 
 

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