Latest Discussions : Electrical & Lighting


06:53PM | 08/09/07
Member Since: 04/25/05
1915 lifetime posts
How much power do you want in the garage?

Do a google for Voltage Drop calculator. For that much of a run you will need to up the size of the wire.


07:04AM | 08/11/07
Member Since: 01/30/05
360 lifetime posts
Are you running above (overhead) or below via conduit in a trench) the earth?


08:52AM | 08/11/07
Member Since: 04/25/05
1915 lifetime posts
With a path that long it realy does not matter the type of insulation. the limiting factor will be voltage drop.


09:03AM | 08/11/07
Member Since: 01/30/05
360 lifetime posts
Think underground in death valley, CA versus overhead in your own neighborhood and you're own limited assumptions! Conduit, exposure, rise, etc. are ALL considerations that effect the overall calculations, sheesh!!! Sheesh voltage drop AND ability to release heat ambient temps, moisture, sealing,...get a grip you have SEVERAL FACTORS to consider here and the question was valid, especially to a minimum 140 foot run.

Note no mention of a sub panel in garage either, nor ground, nor preventing a return loop.

Stop thinking with blinders on!

IF and WHEN the original poster EVER returns to this string to provide necessary information, oh and that includes if this is an agricultural/residential or strictly residential environment, and WHERE in the WORLD (ambient temps, etc.) the poster is..further discussion would be warranted, as would inquiry, precautions regarding alum, al/co and/or al to co connections.


03:34PM | 08/13/07
Member Since: 08/08/07
2 lifetime posts
OK well sorry I did not give you enough info. I apologize. OK we are going underground with it. It will be a 50amp service. it will connect in the breaker box in the house but will then have its own breaker box in the garage.


06:28PM | 08/13/07
Member Since: 04/25/05
1915 lifetime posts
Because of the distance you will need #6 copper or #4 AL.

You will need a ground electrode system at the garage. Being new construction you might have a ufer (concrete incased electrode) that was installed when the footings where poured.

Other wise 2 ground rods, 6 ft apart are used.

There are options for either 3 or 4 wire installation.



03:15AM | 08/31/07
Member Since: 08/27/07
23 lifetime posts
the grounding electrode or "ground rod" needs to be connected at the main disconnect of system or in some cities the grounding electrode is connected to the neutal in the meter base, all sub panels need to have a grounding conductor pulled along with the neutral and power conductors, driving a seperate ground rod at a tail panel can cause a difference of potential to ground....

doug seibert

03:43AM | 08/31/07
Member Since: 08/10/02
842 lifetime posts
That's just wrong there BOB.......

A system can have as many grounding rods as necessary or desired.......(and a detached garage requires one)

But only ONE point of connection/bond between the Grounding Electrode and Neutral at the Main.........

"...measure once.....cut twice....throw that one away and cut a new one...."


04:34AM | 08/31/07
Member Since: 04/25/05
1915 lifetime posts
Any and allof the types of electrodes that you have below MUST be used.

a. metal underground water pipe at leat 10 ft long. **

b. metal frame of a building where effecticely grounded.

c. Concrete encased electrode (UFER).

d. ground ring.

For new construction a UFER is being required where practical.

** As the water pipe might be replaced with a plastic pipe it requires a suplimentry electrode. If one of the above is availalble then you won't need anything else.

other wise it is most common to use ground rodS.

A single ground rod is not accesptable unless it has been tested and found less than 25 ohms to ground. That is a specialized test and rareely done. Thus is common to use two ground rods at least 8 ft apart.

"But only ONE point of connection/bond between the Grounding Electrode and Neutral at the Main........"

That is within a STRUCTURE.

The garage, in this case, is a separate structure.

If there no other metalic paths to the garage then it does not have to have a 4 wire connection. It can be supplies with 2 nots and neutral. Then the neutral and ground will be bonded at the garage.

If a 4 wire system is used then the neutral is unbonded.

In either case the garage needs a full ground electrode system.


11:36AM | 08/31/07
Member Since: 08/27/07
23 lifetime posts
I called my local electrical inspector, and he confirmed what i was saying, but upon further review, I agree that a second ground rod at the out building shall be installed if there is more than one circuit being used in garage no ground rod is required if only a single circuit is being used, appearantly I am working under a local interpetation that may need to be challenged...

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