Need help on overhead garage feed

[darkomega69]

Hello. New user here! Take it easy on me. I've been researching for the last couple of days. From the picture below, you can see that I have a detached garage feed by a 120v 15a breaker. Just lights, couple of outlets, and a garage door opener in the future. It's old, sagging, and 2 wires only. It's about 28 feet. I would like to make it safer but also not break the bank. What I'm thinking is use stainless steel aircraft cable as a messenger. 10-2 plus ground UF, uv resistant wire, ziptied with uv resistant zipties. The ground would not be used until I get an electrician to run a 3 wire to the j-box, so replace the breaker for a gfci type for protection. My questions are:

1. What size should the messenger be?
2. 10 gauge is good for the distance, what if I upgrade to 20amps later?
3. With the gfci, and since it's only for light use, I don't need a ground rod at the garage?
4. How should i secure the messenger? I'm thinking some kind of clamp that would secure the messenger to itself after going around the porcelain insulator.
5. Since it's going on the porcelain insulator. The messenger doesn't have to be grounded?
6. Last, I tried to find where I read it, but something about a single circuit running beside steel can cause a magnetic field?

Thanks for the help.

 

[rkevins]

Welcome, I know you ask about overhead but IMHO

If at all possible I would not go back overhead, I would trench and burry a line with at least a 100a service

 

[darkomega69]

Welcome, I know you ask about overhead but IMHO

If at all possible I would not go back overhead, I would trench and burry a line with at least a 100a service

Thank you for the response. It's my first home and it's old. So a lot of other things to fix. That may be possible in the future. From the pictures, you can see there is a wall. It's cement on one side and asphalt on the other. I think underground will end up going under the concrete. It's something I don't want/have the resources to do right now. So I'm looking to just make it safer than what it is, and maybe a little more aesthetically pleasing, for minimal cost.

 

[kursplat]

#4 or #6 AL triplex overhead wire EXAMPLE find it at the local big box store, electrical supply or see it you can buy it from the local utility. a couple of makeups and attachment points you'll be good to go.

good luck

 

[pattenp]

The messenger cable has to be grounded. NEC 396.60.

 

[darkomega69]

#4 or #6 AL triplex overhead wire EXAMPLE find it at the local big box store, electrical supply or see it you can buy it from the local utility. a couple of makeups and attachment points you'll be good to go.

good luck

Thank you for the link. So the bare strand will be messenger and ground? I looked around that site for to see what kind of connectors I would use to attach such large cables to 12 gauge cables. Split bolts in the junction box? And then wedge clamps to the porcelain insulators? Thanks.

 

[darkomega69]

The messenger cable has to be grounded. NEC 396.60.

As I mentioned before, it's only neutral and and hot from the house. Should I then drive a ground rod at the garage and bond it to the messenger, for the time being? If i go with #6 for the triplex, same size for the ground wire?

 

[matt151617]

The garage does require a ground rod (2 actually; 1 if you can prove a certain amount of resistance, but everyone does 2), but that's for another reason. You still need a ground back to the main panel.

Personally, I would just do it the right way now... either go overhead with large wires, or go underground with conduit. Spend the money, time, and effort now, and never have to worry about it again. Wire isn't cheap, and neither are electricians.

Put in a 100 amp panel, 2 ground rods with #6 copper, and a 4 wire mobile home feeder (aluminum) in 1.5 or 2" conduit. Depending on how wide the concrete is, you may be able to tunnel under it.

I believe the triplex has the same size ground, but you might as well get quadplex. It'll cost a tiny bit more but double your available amps at 120, or make 240 available.

 

[VHF]

I see several low-cost options to keep what you have but make it safer:

(1.) Run just two conductors (hot & neutral) between house and garage. Keep using 2-prong recepticals in the garage. Put the entire circuit on a GFCI breaker in your house panel. You have no ground in the garage, but do have GFCI protection for safety. Consider a non-metalic messanger cable to avoid issues with needing to ground it.

(2.) Run two conductors (hot & netural) between house and garage. Install 3-prong GFCI recepticle(s) in the garage labeled "No Equipment Ground". Do not attempt to bond neutral and ground as you still have no ground in the garage.

(3.) Run two conductors (hot & netural) between house and garage. Treat them as 2/3 of a traditional 3-wire 240V feeder (which was allowed under NEC up until 2008 if there is no other metalic path between strauctures.) Run them into a panel in the garage. Bond the neutral & ground in the panel and run #6 CU to two ground rods 6' apart. Install GFCI breakers in garage or use GFCI recepticles.

(4.) Run 3 conductors (hot, neutral, ground) from house to garage and keep the neutral and ground isolated in the garage. Ground rods are not required at the garage if only a 15A or 20A circcuit and it is GFCI protected at the house. But you would have to have the ground wire hooked up to a good ground at the house end. Under current code the ground would need to run with the other circuit conductors, but in the past is was common to run a separate ground wire to a metal water pipe that is in turn bonded to the main panel ground.

 

[kursplat]

Thank you for the link. So the bare strand will be messenger and ground? I looked around that site for to see what kind of connectors I would use to attach such large cables to 12 gauge cables. Split bolts in the junction box? And then wedge clamps to the porcelain insulators? Thanks.

split bolts would work fine. wedge clamps are easy and cheep. the bare is the neutral. drive a ground rod at the garage panel and i believe you need to make sure the ground buss and neutral are seperated at the sub panel

good luck