garage panel

[Mike01]

My neighbor recently had a service upgraded to his garage when I was over there yesterday I was looking at the installation and a couple things seemed to be missing he had an old Edison based fuse panel with only 4 sockets, he replace it with a 60A MLO panel board, the load side of the meter was tapped and disc placed adjacent to it with a 60A breaker within it. The N-G connection is made at the disc and 4-W run to the garage panel approx 20? away from the house where there is a ground bar bonded to the cabinet and the neutral not bonded as no ground screw was used to bond the neutral to the case. My question is that no ground rods were installed, should the garage panel have a ground rod. I thought you had to place a ground rod at a panel in a separate structure? Would you be required to put one at the disc. Located at the disc. Sw adjacent to the meter also??

 

[charlie b]

My ?short answer? to the question I think you are asking is that every building that has wires bringing electricity to something inside must have a ground rod (or other qualifying electrode).

But I am confused. Is this really a ?service?? Is the utility providing separate services (including separate meters) for the house and for the garage? Is there any power going from the house to the garage, or vice versa?

 

[petersonra]

something I have often wondered.

since grounding electrodes do not serve much of a purpose anyway, how does having one at a separate structure improve electrical safety?

the stated purpose of having a GES is to limit voltage during lightning strikes, line surges, etc. That makes sense when it is connected to neutral.

At a separate structure, it is connected to the EGC rather than neutral. How does this help anything?

 

[lpelectric]

I'm not clear on whether the housew has a meter that is tapped for a disconnect to the garage....or exactly what this installation really is, but I believe you need a grounding electrode system for the disconnect adjacent to the meter, since this would be a service....and if there's a remote panelboard located within the garage the 4th wire should come back to the service disconnect.....if the remote panelboard is the only panelboard/disconnect within the garage, it should have a grounding electrode system established as per 250.32...but I can't fully understand the layout you're discussing...:smile:

 

[Mike01]

layout

layout

on the back of the house is the meter for the house it is a 100A service with #2SER cable, connected to the load side of the meter, also under the load side of the meter is a set of conductors that run from the meter thru a nipple to a disc. switch (C.B. in 3R enclosure) from the secondary of the C.B. there are 4 wires 2 hot, 1 neutral, and 1 ground run in pvc under ground for 25' stubed into the garage and feed a small c.b. panel board in the garage. however no additional ground rods were installed, the question I had is a ground rod required at the grarage panel and connected to the ground bus because the garage is technically a seprate structure, and would one be required at the disc. located adjacent to the meter? I was reading 250 but kept getting stuck in loop.

 

[lpelectric]

on the back of the house is the meter for the house it is a 100A service with #2SER cable, connected to the load side of the meter, also under the load side of the meter is a set of conductors that run from the meter thru a nipple to a disc. switch (C.B. in 3R enclosure) from the secondary of the C.B. there are 4 wires 2 hot, 1 neutral, and 1 ground run in pvc under ground for 25' stubed into the garage and feed a small c.b. panel board in the garage. however no additional ground rods were installed, the question I had is a ground rod required at the grarage panel and connected to the ground bus because the garage is technically a seprate structure, and would one be required at the disc. located adjacent to the meter? I was reading 250 but kept getting stuck in loop.

I think you can get "unstuck" in the loop, by just reading 250-32 which starts out saying: "Building(s)...supplied by feeders shall have a grounding electrode system installed in accordance with 250.50..." the last part of 250.50, It says that if there isn't a system, you must install one. :smile:

 

[Mike01]

main disc

main disc

would the main disc adjacent also be required to have a ground rod or would one at the seprate structure be sufficent, my opinion was you are not really serving a seprate structure, it is basiclly treated as a service as you are coming from the load side of the meter not the panel interior to the house So the N-G connection would be made at the disc. Located adjacent to the meter with the garage being only 15-20 feet away and this being the main disc. This really would not be feeding a sprate structure it is more of a service so the ground rod would be installed where the disc. Is located adjacent to the meter and not required in the garage, however the N-G connection would still be made at the disc. Making this the ?service? and 3W+Grd. Brought to the garage panel.

 

[lpelectric]

would the main disc adjacent also be required to have a ground rod or would one at the seprate structure be sufficent, my opinion was you are not really serving a seprate structure, it is basiclly treated as a service as you are coming from the load side of the meter not the panel interior to the house So the N-G connection would be made at the disc. Located adjacent to the meter with the garage being only 15-20 feet away and this being the main disc. This really would not be feeding a sprate structure it is more of a service so the ground rod would be installed where the disc. Is located adjacent to the meter and not required in the garage, however the N-G connection would still be made at the disc. Making this the ?service? and 3W+Grd. Brought to the garage panel.

In my way of thinking, the garage feeder requires the grounding electrode system as spelled out in 250-32 and 250.50. If the disconnect adjacent to the meter installed on the house is a service point, then it, too, requires a grounding electrode system...since it's a main service disconnect....right?:smile:

 

[Mike01]

Service Point

Service Point

Yes I agree the Disc adjacent to the meter would require a ground rod but I am debating if the garage is required to have one you are not really feeding one building from another you are feeding it from the meter? I would think (if you could find it) you could bond to the same ground rod as the one provided for the house, another question just popped into my head I will do some research but off the top of my head if the connection to the meter is a ?tap? if it is outside and then underground to the garage is the disconnect at the meter even required since the tap is outside and underground it can be of unlimited length, then you would treat the panel in the garage as the service point bonding the neutral to the case and providing a ground rod at the panel. Does this make sense??

 

[lpelectric]

OK, Mike01, see if this makes any sense to you...I'm just rambling...
I can envision an underground lateral or overhead service drop to this house entering the metering enclosure and the load side lugs on the metering enclosure being doubled and from this point one set of service conductors going into a main-breaker panelboard within the house, and the other set of service conductors travelling underground 20-25' to the garage and entering there as a true service. I think maybe you're talking about Exception #3 to 230.40. Let me know....:smile: I also think you could share the grounding electrode system by installing grounding electrode conductors of adequate length.:smile:

 

[charlie b]

If you are inside the house, and if there is a major rainstorm going on, and if you can not manage to get from the house into the garage without getting wet, then the garage is a separate structure. To be specific, unless the house and the garage share a wall, they are separate structures. If there is a covered walkway between the two, and in particular if the covered walkway also has side walls, then the situation is less obvious. But it sounds to me like there is clear space between them. That makes them separate structures.

Every structure needs its own ground rod. If you are suggesting that the house and the garage are close enough to each other that a single ground rod located somewhere between the two might suffice for both, I cannot answer you.

This does sound to me like separate services. However, since they share a single meter, I am not certain of that. Still, there is a disconnecting means between the meter and the conductors going underground to the garage. That tells me that,

(1) The neutral and ground bond should take place within the same enclosure as the disconnect switch,

(2) The conductors from that point to the garage comprise a ?feeder,? and not a ?service,?

(3) The neutral and ground bars within the garage panel should not be bonded to each other, and

(4) The required ground rod at the garage should be connected to the ground bus within the garage panel.

 

[Mike01]

another twist???

another twist???

charlie b I totally agree with your response do you believe that a ground rod is also required at the disc??


Thinking about this a little bit more and posing the question from my last post. Why install a disc adjacent to the meter? Why not just route the ?service? from the meter double lugged on the load side of the meter under ground stubbed into the garage or separate structure whatever it may be shed, garage whatever. The panel then would be a service and the box bonded to the neutral and connected to a ground rod via #?? Wire. I guess my question is could you install this as another service and provide SE cable from the meter to the garage panel underground and not supply the disc. At the meter. The conductor would be outside and underground there fore could be of unlimited length correct?

 

[charlie b]

charlie b I totally agree with your response do you believe that a ground rod is also required at the disc??

Yes I do. But presuming the disconnect is attached to the house in some manner, I would not object to using the same ground rod for the disconnect and for the house main panel.

Why not just route the ?service? from the meter double lugged on the load side of the meter under ground stubbed into the garage or separate structure whatever it may be shed, garage whatever. The panel then would be a service and the box bonded to the neutral and connected to a ground. . .

I think that can be done as well. It?s a design choice, not an NEC requirement, to do it one way or the other.

I guess my question is could you install this as another service and provide SE cable from the meter to the garage panel underground and not supply the disconnect at the meter.

I can?t speak to the question of what type wire can be used for what purpose and be routed underground. Someone else will have to take up this item.

The conductor would be outside and underground there fore could be of unlimited length correct?

Correct. Once you get to the garage, however, you will have to hit a disconnecting means either outside or inside at a point nearest the point of entrance of the conductors. In WA State, you have a limit of 15 feet inside the building, before you must hit a disconnect.

 

[cschmid]

Charlie sounds accurate on his answers..and if I get the question correctly it is whether the ground rod at the house is good enough or if you need to drive one at the garage. The disconnect on the house is the real issue here..because it becomes the service main and it does need to be bonded and grounded..than separate conductors with a ground would be correct.. Now comes the next issue I would believe since it is a separate structure you would have to drive a ground rod and connect it to your ground buss.. I also believe you need a disconnect means on the structure and it would now be unfused disconnect.. So I think you would have to add both items..this is an expensive way to install a service to ones garage..

 

[lpelectric]

You know, the more I look at this question and the more I think about the grounding electrode system requirements, the more I am inclined to believe that even though the garage building service equipment is only 20' away from the house service equipment, the garage service should have its' own grounding electrode system and the house should have its' own, too. I think the language (the use of the word "each") at 250.50 dictates that. :smile:

 

[petersonra]

You know, the more I look at this question and the more I think about the grounding electrode system requirements, the more I am inclined to believe that even though the garage building service equipment is only 20' away from the house service equipment, the garage service should have its' own grounding electrode system and the house should have its' own, too. I think the language (the use of the word "each") at 250.50 dictates that. :smile:

250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.

Interestingly, it does not state that you should bond the electrodes present at each seperate structure only at the seperate structure. Read literally, it means you have to bond all the GE together from all the structures.

That would imply running the GEC from the garage ground rod back to the house GES, and not attaching it to the ground bar in the garage, which would make a lot more sense than the way it is presently done.

 

[Mike01]

different opinion

different opinion

After reading thru all the post, I agree this installation seems a little wierd if this were my installation I would just tap the load side of the meter route down the face of the house, underground to the garage (however far it is) and provide a panelboard in the garage bond the N to the case drive a ground rod and connect that to and call it a day. I guess why install a additional disc if you are not requied. charlie b when I stated SE cable it may not have been the correct choice it was just thrown out there as an example for a 60A service I would provide 2#4RHW&1#8Grd. in 2"C. for a 60A service.

 

[Dennis Alwon]

After reading thru all the post, I agree this installation seems a little wierd if this were my installation I would just tap the load side of the meter route down the face of the house, underground to the garage (however far it is) and provide a panelboard in the garage bond the N to the case drive a ground rod and connect that to and call it a day. I guess why install a additional disc if you are not requied. charlie b when I stated SE cable it may not have been the correct choice it was just thrown out there as an example for a 60A service I would provide 2#4RHW&1#8Grd. in 2"C. for a 60A service.

I agree with charlie that the disco for the garage need not be at the meter, however if it is I would think it would need to be grouped with the house disco. There was a long debate on this posted by Mike Whitt awhile back.

A far as the grond rods -- If the house has a ground rod driven and connected to the service meter than you would not need another connection to the disco on the house.

You would definitely need ground rods at the garage and in your case connected to the ground bar and the neutral bar stays isolated.

If there were no metallic pathways between the buildings you could still have installed a 3 wire to the garage and bond everything as if it were a service.

You still need to have the 6 disco rule or a main disco at the garage.

I do not agree that the gec from the house needs to be directly connected to the gec at the garage as someone suggested.

 

[Mike01]

3-wire

3-wire

If there were no metallic pathways between the buildings you could still have installed a 3 wire to the garage and bond everything as if it were a service.

This may be a misinterpertation on my part but accorkding to 250.32(b)(2)

Where (1) and equipment grounding conductor is not run with the supplyt to the building or structure, (2) there are no continuous metallic path bonded to the grounding system in each building or structure involved, and (3) Ground -fault protection of equipment has not been installed on the supply side of the feeder(s),....

The text indicated in bold ground fault protection is not installed on the supply side but the receptacles in a residental garage are require to be gfci protected would this be a violation?

 

[benaround]

Mike,

Don't confuse GFPE with GFCI, easy to do.

Also, I agree with Dennis 100% on, You need to group the disconnects, or install one disconnect as the MAIN, as it sits

right now you have a 160a service with only 100a capacity wire. The garage needs it's own disconnect no matter how you

handle to house side, and lastly, the GES at the garage needs to be installed. Beside that, everything else looks good.