Electrical Question - Everybody loves them!

[Scott 730]

However, a ground rod should not be installed at the subpanel with a four-wire system

?????

 

[zuhnc]

GROUND rods can be installed anywhere, and sometimes more than one at a given location. If all the equipment GROUNDS are tied together, that makes for a more equi-potential system, referenced to ground, and less of a chance for damage due to lightening surges, etc. You do not want the NEUTRAL tied to the grounds but in one place only, generally the main panel. I have four different outbuildings supplied by one panel, and they ALL have driven ground rods, and they are all tied together by the equipment grounding conductor. All four outbuildings are 4-wire (up to code) installations. zuhnc

 

[John T]

GROUND rods can be installed anywhere, and sometimes more than one at a given location. If all the equipment GROUNDS are tied together, that makes for a more equi-potential system, referenced to ground, and less of a chance for damage due to lightening surges, etc. You do not want the NEUTRAL tied to the grounds but in one place only, generally the main panel. I have four different outbuildings supplied by one panel, and they ALL have driven ground rods, and they are all tied together by the equipment grounding conductor. All four outbuildings are 4-wire (up to code) installations. zuhnc

EXACTLY There is to be ONLY ONE NEUTRAL GROUND BOND

John T

 

[wp6529]

I agree on your wire selection and method selection. However, a ground rod should not be installed at the subpanel with a four-wire system and the bonding screw at the subpanel which should exist and was required in the old system should be removed.

Ground rods are required at the subpanel when it is in a separate structure.

 

[guido]

Yesterday's Tractors Tools Forum,
I recently purchased a log cabin built in 1985.
Cabin is 28 by 32 with a new 200 amp Square D Main Panel I installed before I was allowed to purchase the cabin. It had a Federal Pacific panel before!
It has a garage about 100 feet away that was built in 2000. 100 amp Square D panel fed from a 100 amp breaker in the main panel.
When they built the garage, they ran 1 1/2" PVC pipe from the house to the garage underground.
They ran 2-2-4 Al URD cable when they built it, I would like to add a GROUNDING wire to the circuit.
I believe that the Neutral and Ground are bonded in both locations. Not up to current code but may have been OK in 2000.

Option one: I could simply push thru a bare copper #4 wire. Take the bond out and be done with it.

BUT we all know we just like to think about the future and what we MIGHT do then and I came up with:
Option two: push/pull a second 2-2-4 AL URD cable thru. I would leave the existing two 2 gauge wires as the line wires. Lable them Red and Blue.
Then use the second set of 2 gauge wires for the Neutral and ground. (of course I would have to get them labeled before I pulled them, one white and one green.)
I could then use the two 4 gauge wires to bring back the line output from a generator circuit that I would install in the garage. I would label them. They could also be Red and Blue.
That circuit would land at a 30 amp breaker in my main panel in the house that would have the lock-out installed to prevent back-feed onto the grid.
I would be using the neutral and ground of the main circuit to complete the 4 wires needed for the generator. The generator I have is not bonded, the neutral and ground are separate. I would use the approved male generator outlet at the garage.

WHY option 2??
The 2-2-4 AL URD cable is cheaper per foot than the single #4 copper wire.
I would be upgrading my Neutral to 2 gauge from 4 as it is now.
I would be able to run the generator circuit. I could then run the generator at the garage under cover (with doors open) and not have to drag it from the garage to the house and leave it run outside.

I know you all just like to listen to other people's ideas and comment. So, I gave you something to ponder on.
Comment away and have a GREAT day!
Keith

Yesterday's Tractors Tools Forum,
I recently purchased a log cabin built in 1985.
Cabin is 28 by 32 with a new 200 amp Square D Main Panel I installed before I was allowed to purchase the cabin. It had a Federal Pacific panel before!
It has a garage about 100 feet away that was built in 2000. 100 amp Square D panel fed from a 100 amp breaker in the main panel.
When they built the garage, they ran 1 1/2" PVC pipe from the house to the garage underground.
They ran 2-2-4 Al URD cable when they built it, I would like to add a GROUNDING wire to the circuit.
I believe that the Neutral and Ground are bonded in both locations. Not up to current code but may have been OK in 2000.

Option one: I could simply push thru a bare copper #4 wire. Take the bond out and be done with it.

BUT we all know we just like to think about the future and what we MIGHT do then and I came up with:
Option two: push/pull a second 2-2-4 AL URD cable thru. I would leave the existing two 2 gauge wires as the line wires. Lable them Red and Blue.
Then use the second set of 2 gauge wires for the Neutral and ground. (of course I would have to get them labeled before I pulled them, one white and one green.)
I could then use the two 4 gauge wires to bring back the line output from a generator circuit that I would install in the garage. I would label them. They could also be Red and Blue.
That circuit would land at a 30 amp breaker in my main panel in the house that would have the lock-out installed to prevent back-feed onto the grid.
I would be using the neutral and ground of the main circuit to complete the 4 wires needed for the generator. The generator I have is not bonded, the neutral and ground are separate. I would use the approved male generator outlet at the garage.

WHY option 2??
The 2-2-4 AL URD cable is cheaper per foot than the single #4 copper wire.
I would be upgrading my Neutral to 2 gauge from 4 as it is now.
I would be able to run the generator circuit. I could then run the generator at the garage under cover (with doors open) and not have to drag it from the garage to the house and leave it run outside.

I know you all just like to listen to other people's ideas and comment. So, I gave you something to ponder on.
Comment away and have a GREAT day!
Keith

Keith,

I had the exact scenario about the same time. I buried pvc for the feed of the garage. The 120v receptacles are 20 amp GFI protected. The garage has it's own ground, and the neutral and ground are NOT bonded as per the inspector request,




Guido.

 

[John T]

Keith,

I had the exact scenario about the same time. I buried pvc for the feed of the garage. The 120v receptacles are 20 amp GFI protected. The garage has it's own ground, and the neutral and ground are NOT bonded as per the inspector request,




Guido.

Good inspector !!!!

 

[guido]

Good inspector !!!!

YEP!

 

[Keith Williams]

Keith,

I had the exact scenario about the same time. I buried pvc for the feed of the garage. The 120v receptacles are 20 amp GFI protected. The garage has it's own ground, and the neutral and ground are NOT bonded as per the inspector request,




Guido.

So you ran a 4 wire run to your garage?
I do not know what code was in 2000? I just know what is there and what I would like to end up with.
Namely 4 wires between the Cabin and Garage. Load 2 #2 gauge, Neutral 1 #2, Grounding 1 #2.
Plus 2 #4 for the Load of the Generator back to the Cabin.

After our discussion here,
I will pull the wires out of the conduit pulling a long rope in.
I will use the rope to swab the conduit and then lube it.
I will measure the length of the wire pulled out and purchase an equal length of 2-2-4 URL AL.
While the wire is out, I will mark the ends of the # 2 wire RED BLUE WHITE and GREEN, while the #4's will be marked RED and BLUE.
I will lube the wire and then pull it thru.
Before I restore power, I will remove the bonding screw at the panel in the Garage.
I will check the grounds at each building.
I will install the generator hook up at a later time.
Thanks for all the replies!
Keith Williams

 

[Dusty MI]

I would use soap/lube made for pulling electric wire.
I also prefer copper wire.

 

[Scott 730]

So you ran a 4 wire run to your garage?
I do not know what code was in 2000? I just know what is there and what I would like to end up with.
Namely 4 wires between the Cabin and Garage. Load 2 #2 gauge, Neutral 1 #2, Grounding 1 #2.
Plus 2 #4 for the Load of the Generator back to the Cabin.


Keith Williams

I'm no sparky, but don't you need more than 2 wires running back from the genny to the main panel to make the generator connection code compliant??

 

[John T]

I'm no sparky, but don't you need more than 2 wires running back from the genny to the main panel to make the generator connection code compliant??

In the jurisdiction and at the time I practiced power distribution engineering per the NEC a 120/240 volt genset required four wires. Two hots one neutral one equipment grounding conductor. Whether or not the genset was configured with a floating or bonded neutral and whether or not it required connection to a grounding electrode depended on if it was a separate derived source and if the neutrals were switched IE the transfer switch configuration. Of course lockout protection was required so the genny couldn’t back feed the utility again in accordance with the nec Things may have since changed I advise consult the nec versus my recall John T

 

[guido]

So you ran a 4 wire run to your garage?
I do not know what code was in 2000? I just know what is there and what I would like to end up with.
Namely 4 wires between the Cabin and Garage. Load 2 #2 gauge, Neutral 1 #2, Grounding 1 #2.
Plus 2 #4 for the Load of the Generator back to the Cabin.

After our discussion here,
I will pull the wires out of the conduit pulling a long rope in.
I will use the rope to swab the conduit and then lube it.
I will measure the length of the wire pulled out and purchase an equal length of 2-2-4 URL AL.
While the wire is out, I will mark the ends of the # 2 wire RED BLUE WHITE and GREEN, while the #4's will be marked RED and BLUE.
I will lube the wire and then pull it thru.
Before I restore power, I will remove the bonding screw at the panel in the Garage.
I will check the grounds at each building.
I will install the generator hook up at a later time.
Thanks for all the replies!
Keith Williams

Sounds like you got it covered. I would have to look at the panel to see if they pulled 4 wires? I did help the electrician, as he was stuck pulling the mains through the pipe he was using. Gave him some red synthetic chassis lube, that did the trick.

Guido.

 

[JMOR]

You really need to get your job done, so that this thread will die! Enough is enough!

 

[Scott 730]

Sounds like you got it covered.

Guido.

........... except the part where he talks about only running 2 conductors from the genny back to the main panel.

 

[Keith Williams]

........... except the part where he talks about only running 2 conductors from the genny back to the main panel.

The neutral and grounding wires are the 2 #2s in the main circuit. I will land the Generator's neutral and grounding wires at the sub panel in the garage. Those wires are not switched (they NEVER run through a breaker). Therefore running 2 more wires just to connect to the same place in the main panel would be redundant and just give me another point of failure.
Also those 2 circuits (neutral and grounding) will not be bonded in any location except at the main panel per code. I have already checked the generator I have and they are not bonded in the generator.
I hope my logic is understandable.
Keith Williams

 

[Keith Williams]

You really need to get your job done, so that this thread will die! Enough is enough!

Is there a way to kill it?? I'm done with this conversation.
Thanks everyone!
Keith

 

[Jim.ME]

Is there a way to kill it?? I'm done with this conversation.
Thanks everyone!
Keith

You could try using the Report button and asking a Moderator to lock it from further replies.

 

[Mike Groom]

Check with a local electrician but here in Ill. we run 3 wires to the sub panel, black-red and white, you have to put two ground rods 10 feet apart and run a copper ground wire in series to the two ground rods (5 foot buried 5 foot in the ground) The sub panel is not grounded to the main panel, and the neutral is separate from the grounds in the sub panel, you may have to install a separate ground bar. There should be NO ground wire between the two panels.

 

[Keith Williams]

You could try using the Report button and asking a Moderator to lock it from further replies.

I have asked for it to be deactivated.
Thank you Jim!
Keith