Grounding rod for Detached garage needed?

[Kevin54]

I have a subpanel in my garage from my house. The new addition has a subpanel off of the main subpanel. The first thing the electrician asked me before he started doing anything, he wanted to know where my ground rod was. I've never had one from when the garage was built back in '99 because it was grounded back to the main. That don't fly in his world I guess, because the first thing I had to do was run a ground rod to get it up to code. 8' and it's right outside the breaker panel on the other side of the wall.

 

[Speedy Petey]

I am just curious and I have never seen a connection like that before and I always thought the wire had to be solid and continuous but I guess the connection method takes care of the ladder.

Certain ground wires (grounding electrode conductors) need to be continuous from one point to the next, but not nearly all. It has become a myth code that all ground wires must be unbroken.

For instance, the wire from a main panel/disconnect to an electrode must be unbroken or permanently spliced, but the wire from one ground rod to a supplemental rod can be a separate piece.

See this illustration:

©Mike Holt

 

[Speedy Petey]

I have a subpanel in my garage from my house. The new addition has a subpanel off of the main subpanel. The first thing the electrician asked me before he started doing anything, he wanted to know where my ground rod was. I've never had one from when the garage was built back in '99 because it was grounded back to the main. That don't fly in his world I guess, because the first thing I had to do was run a ground rod to get it up to code. 8' and it's right outside the breaker panel on the other side of the wall.

What you had was never code as far as I can remember, and definitely NOT in '99.
A detached structure served by a feeder (sub-panel) always required a grounding electrode (again, at least going back 25-30 years), and this has/had NOTHING to do with the fact that a ground wire was run with the feeder from the main. Two totally different animals.

 

[wyliesdiesels]

I am just curious and I have never seen a connection like that before and I always thought the wire had to be solid and continuous but I guess the connection method takes care of the ladder.

We do those at work all the time!

Far better than an acorn or pipe clamp!

I have a subpanel in my garage from my house. The new addition has a subpanel off of the main subpanel. The first thing the electrician asked me before he started doing anything, he wanted to know where my ground rod was. I've never had one from when the garage was built back in '99 because it was grounded back to the main. That don't fly in his world I guess, because the first thing I had to do was run a ground rod to get it up to code. 8' and it's right outside the breaker panel on the other side of the wall.

As speedy said, An EGC and a grounding electrode are 2 different things that are very often confused! Dont confuse the 2! They are both required on a feeder for a detached structure.

Read this article:

http://www.electriciantalk.com/articles/the-confusion-of-the-term-grounding/

 

[acer66]

Thank you Speedy Petey and wyliesdiesels for clearing this up.

 

[roadrunner255]

Hello all,

My 12 x 36 x 40 garage is in the process of getting formed for the foundation and slab and I ran across a thread that said a detached garage needed a grounding rod.

The previous owner prewired a PVC box enclosure on the outside of the house and main fuse panel with a 100 amp breaker and has THHN 2 gauge in the outside box.

Detached garage is only 35' from the box attached to the main house, would I still need to run a grounding rod?

If so I need to install the grounding wire before they pour the concrete.

Could I place the grounding rod in the footer (40" deep) and run the bare wire up through the concrete or do I need conduit?

Thanks in advance!

Trying to figure out what size (and part number) of polaris splice connector (black) that I would need to splice the house main panel wires and the garage sub panel wires, both are 4 #2 AWG AL wires.

A junction box is located on the outside of the house where there is a home run from the main 200 amp panel. I will be splicing the detached garage 4 #2 AWG AL to the house (100 amp breaker) 4 #2 AWG AL in the junction box.

Cheers!

 

[pattenp]

I'd use these with shrink tube or good electrical tape. Polaris is too expensive.

http://www.lowes.com/pd_36042-12704-770143L___

Here's the polaris you need....
http://www.globalelectricalsupply.c...rasl-0-14AWG-Insul-Tap-Connector-p/it-10b.htm


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[wyliesdiesels]

http://www.polarisconnectors.com/pdfs/NSi/IT_series.pdf

And the breaker needs to be 90a not 100a.

 

[roadrunner255]

http://www.polarisconnectors.com/pdfs/NSi/IT_series.pdf

And the breaker needs to be 90a not 100a.

I'd use these with shrink tube or good electrical tape. Polaris is too expensive.

http://www.lowes.com/pd_36042-12704-770143L___

Here's the polaris you need....
http://www.globalelectricalsupply.c...rasl-0-14AWG-Insul-Tap-Connector-p/it-10b.htm


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Thanks! Would you know if the 2 AWG AL SER is fine stranded or not?

 

[wyliesdiesels]

Thanks! Would you know if the 2 AWG AL SER is fine stranded or not?

Well that depends on your definition of fine stranded.

If its the southwire brand, it only has 7 strands which i dont believe qualifies as fine stranded.

http://www.southwire.com/ProductCat...eview=true&token=273&desc=AL SE, SER, and SEU

 

[roadrunner255]

Polaris said not to use their black splices on fine stranded, to use their gray splice.

Sent from my SM-N900V using Tapatalk

 

[roadrunner255]

Good morning all,

I am trying to determine the type of cable to run from the outside junction box to the new building in buried conduit (about a 50' run to the sub panel).

Current cable run from the main panel (wire in attic and inside wall into pvc junction box) to the junction box is 4 #2 AL mobile home feeder. Can I use this same cable or go with a bundled 4 wire cable, or these cables, SER, URD?

Thanks!

 

[Speedy Petey]

Good morning all,

I am trying to determine the type of cable to run from the outside junction box to the new building in buried conduit (about a 50' run to the sub panel).

Current cable run from the main panel (wire in attic and inside wall into pvc junction box) to the junction box is 4 #2 AL mobile home feeder. Can I use this same cable or go with a bundled 4 wire cable, or these cables, SER, URD?

Thanks!

You CANNOT use MHF cable without conduit. Are you saying you have it run exposed in the attic and walls???

I would use MHF in the conduit outside, that's it's main purpose.

 

[roadrunner255]

You CANNOT use MHF cable without conduit. Are you saying you have it run exposed in the attic and walls???

I would use MHF in the conduit outside, that's it's main purpose.

The cable coming from the main panel in the attic to the junction box looks like its a mobile home feeder, with #2 ground. See attached photo.

MHF in conduit is my best choice? When I search on MHF cable all I find is SER cable or mobile home feeder.

Thanks!

Southwire sheet says;
Southwire Mobile Home Feeder consists of four quadruplexed type RHH or RHW-2 or USE-2 AlumaFlex™ AA-8000 series aluminum alloy compacted conductors. The cable contains a triple extruded white striped neutral conductor and a solid green grounding conductor to eliminate the need for field marking per the NEC. Insulation is sunlight resistant.

Specs are;
Cable shall be UL-listed Type RHH or RHW-2 or USE-2, suitable for direct burial and operation at 600 volts. Conductors shall be AlumaFlex™ aluminum alloy as manufactured by Southwire Company or approved equal. The cable shall contain a triple extruded white striped neutral conductor and a solid green grounding conductor to eliminate the need for field marking per the NEC.

 

[pattenp]

The cable you pictured is Mobile Home Feeder (MHF) and needs to be in conduit where inside the structure because it does not have an overall outer jacket. SER has an overall outer jacket and can be used inside without conduit and the installation is the same as NM-b. SER cannot be placed underground, MHF can be placed underground, direct bury or in conduit. MHF can be used inside because of the RHH/RHW rating whereas URD in most cases has to stay outside because it only carries a USE-2 rating.



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[wyliesdiesels]

The cable coming from the main panel in the attic to the junction box looks like its a mobile home feeder, with #2 ground. See attached photo.

MHF in conduit is my best choice? When I search on MHF cable all I find is SER cable or mobile home feeder.

Thanks!

Southwire sheet says;
Southwire Mobile Home Feeder consists of four quadruplexed type RHH or RHW-2 or USE-2 AlumaFlex™ AA-8000 series aluminum alloy compacted conductors. The cable contains a triple extruded white striped neutral conductor and a solid green grounding conductor to eliminate the need for field marking per the NEC. Insulation is sunlight resistant.

Specs are;
Cable shall be UL-listed Type RHH or RHW-2 or USE-2, suitable for direct burial and operation at 600 volts. Conductors shall be AlumaFlex™ aluminum alloy as manufactured by Southwire Company or approved equal. The cable shall contain a triple extruded white striped neutral conductor and a solid green grounding conductor to eliminate the need for field marking per the NEC.

Its a #4 EGC.

that MHF needs to be in conduit.

 

[roadrunner255]

Thanks all for the help, now I just need to figure out how to run service around the garage for receptacles and lighting.

I have seen some posts that run conduit outside of the walls. I will be installing 3/4" T&G plywood for the walls and prefer to run service in the wall (8" perlins).

When I installed service in a metal stud wall I used grommets, and I assume they make the same for thicker material.

Cheers!

This is the MHF I plan on purchasing;

http://www.wireandcabletogo.com/Aluminum-Building-Wire/Mobile-Home-Feeder/2-2-2-4-Aluminum-Mobile-Home-Feeder-Cable.html

 

[pattenp]

The picture of the cable for the MHF on the wireandcabletogo site is wrong. The picture is of URD cable with a yellow striped neutral. At least the printed specs are correct for MHF. MHF should be 2 black, 1 black/white striped, 1 green.

 

[roadrunner255]

For the ufer ground to the sub panel #4 copper or #6 bare copper (10' run)?

Thanks!

 

[roadrunner255]

The picture of the cable for the MHF on the wireandcabletogo site is wrong. The picture is of URD cable with a yellow striped neutral. At least the printed specs are correct for MHF. MHF should be 2 black, 1 black/white striped, 1 green.

Thanks, getting ready to order 45' of cable to connect from the main panel to the sub panel. I was going to run 2-2-2-4 mobile home feeder as suggested but, wanted to make sure there are no other options before ordering.

I have 1 1/2" conduit in a trench current cable is 2-2-2-4 alum MHF, are there any other options to the aluminum eg copper? I will be using the 2 lug splices rated for either copper or aluminum.

Not sure if you are allowed to connect copper to aluminum via splicers.

Cheers!