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  1. #1
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    Default 2 main panels (only 1 has a ground)

    Inspected this 4000 sq ft house today that had (2) 200 amp main breaker panels. The only thing I saw was that panel A was the only panel that had a visible ground ? I searched and searched, even went back out side to look for a main disconnect, which I didn't find. I'm going to call for an electrician to evaluate.

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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Sam Morris View Post
    Inspected this 4000 sq ft house today that had (2) 200 amp main breaker panels. The only thing I saw was that panel A was the only panel that had a visible ground ? I searched and searched, even went back out side to look for a main disconnect, which I didn't find. I'm going to call for an electrician to evaluate.
    Which panel is panel A? What ground are you referring to? What was the wiring method?

    All answers based on unamended National Electrical codes.

  3. #3
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Jim Port View Post
    Which panel is panel A? What ground are you referring to? What was the wiring method?
    Panel A is on the left with the green sheathing grounding connector wire at the top left of panel. Ground electrode had to be a UFER or a rod in ground, no metal pipes in this house
    2 200 amp breaker panels, Panel A 4/0 aluminum 2 hot, 1 neutral for panel A on left side. Panel B is 4/0 aluminum 2 hot, 1 neutral no grounding electrode (green wire visible). All I could see really was a rod in the ground at the pole in the yard (at meter base), then service wires going underground about 150 to panels in basement.


  4. #4
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Sam Morris View Post
    Panel A is on the left with the green sheathing grounding connector wire at the top left of panel. Ground electrode had to be a UFER or a rod in ground, no metal pipes in this house
    2 200 amp breaker panels, Panel A 4/0 aluminum 2 hot, 1 neutral for panel A on left side. Panel B is 4/0 aluminum 2 hot, 1 neutral no grounding electrode (green wire visible). All I could see really was a rod in the ground at the pole in the yard (at meter base), then service wires going underground about 150 to panels in basement.
    Help me out here. I see neutral and ground conductors on the same bus.
    panel wiring.JPG

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  5. #5
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by ROBERT YOUNG View Post
    Help me out here. I see neutral and ground conductors on the same bus.panel wiring.JPG
    Yes ?? Both Main Panels, not main disconnect outside, wired as a secondary panel, Panel B on right missing the ground ?? Im I missing something panel B has 2 hot 1 neutral and NO grounding electrode (GEC) visible like normal ? (this house was built in 2003)

    Last edited by Sam Morris; 10-16-2019 at 03:29 AM.

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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Sam Morris View Post
    Inspected this 4000 sq ft house today that had (2) 200 amp main breaker panels. The only thing I saw was that panel A was the only panel that had a visible ground ? I searched and searched, even went back out side to look for a main disconnect, which I didn't find. I'm going to call for an electrician to evaluate.
    Where does that black wire in the same approximate location as the green ground on panel A go to ?


  7. #7
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Phil brody View Post
    Where does that black wire in the same approximate location as the green ground on panel A go to ?
    Not there ? Maybe a bad angle in other picture

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  8. #8
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    Default Re: 2 main panels (only 1 has a ground)

    If there is no disconnect outside (upstream of these disconnectdisconnects), then these two panels are "service equipment" panels.

    Thinking of them, and referring to them, as "service equipment" panels may help with understanding what is there, what is not there, and why.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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    Default Re: 2 main panels (only 1 has a ground)

    Sam Morris
    First you stated that these are sub-panels. If so there is a meter main somewhere. You never stated that it exists. The meter main should have 2 ground rods 8 ft apart. You mentioned one ground rod near the meter can 150 ft away).

    Since the feeders are not jumped between A and B then it seems you have two feeder runs. If I recall correctly there must be a ground run from the meter main to EACH sub panel with each feeder run. Also there would need to be ground rods for these panels regardless as they are more than XXX feet from the meter main.

    I would check the bonding screws on each panel to find what the intent of the electrician was when installed. That may tell you something provided they did this with some actual intent. However, it may be that they ran BOTH panels as mains as both have the same wiring size and distance from the meter. Also, how are the two panels grounded together? they need to be regardless of intent at install as there is only one ground run with the feeders (which is wrong no matter what I think as sub-panels must have a ground run with the feeders.)


  10. #10
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Dirk Jeanis View Post
    The meter main should have 2 ground rods 8 ft apart.
    Two ground rods are not required, and the minimum separation between ground rods is 6 feet, not 8 feet.

    And it is better (And accurate) to think in terms of "service equipment" panel(s) and "other than service equipment" panel(s).

    What is a "main" panel? It is not necessarily, but could be, the "service equipment" panel(s).

    Jerry Peck
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  11. #11
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    Default Re: 2 main panels (only 1 has a ground)

    These are both service panels with main breakers. The neutral appears to be bonded to ground in both panels. Assuming these really are the main service panels there's nothing wrong with that!

    There doesn't have to be a main disconnect on the exterior as long as you do not go into the house more than 5-feet.

    There should however be ground rod/s located at or near the meter and a bond to the cold water. Even if the house has no metal plumbing pipes the plumber usually stubs out with a piece of copper tubing capped off for the water bond. The water bond can also be attached to the pipes supplying cold water to the water heater.

    Last edited by Joe Martin; 10-16-2019 at 08:13 AM.

  12. #12
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Joe Martin View Post
    There doesn't have to be a main disconnect on the exterior as long as you do not go into the house more than 5-feet.
    Please clarify what you mean be "you" and "do not go into the house more than 5-feet".

    There should however be ground rod/s located at or near the meter and a bond to the cold water.
    Not necessarily.

    Even if the house has no metal plumbing pipes the plumber usually stubs out with a piece of copper tubing capped off for the water bond.
    That may be a practice in your area, if so, then that piece of copper tubing would have to be connected to an underground metallic water pipe to be of any use, and then that use would only be as a connection to the metallic underground water pipe, if that is even metal (I suspect that most are PVC or some other plastic material instead of metallic in the last several decades, maybe some places are still using copper water service lines?).

    The water bond can also be attached to the pipes supplying cold water to the water heater.
    To clarify "water bond": you are not saying that the "water" is bonded, you are only using "water bond" to indicate metallic water piping", correct?

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
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  13. #13
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Dirk Jeanis View Post
    Sam Morris
    First you stated that these are sub-panels. If so there is a meter main somewhere. You never stated that it exists. The meter main should have 2 ground rods 8 ft apart. You mentioned one ground rod near the meter can 150 ft away).

    Since the feeders are not jumped between A and B then it seems you have two feeder runs. If I recall correctly there must be a ground run from the meter main to EACH sub panel with each feeder run. Also there would need to be ground rods for these panels regardless as they are more than XXX feet from the meter main.

    I would check the bonding screws on each panel to find what the intent of the electrician was when installed. That may tell you something provided they did this with some actual intent. However, it may be that they ran BOTH panels as mains as both have the same wiring size and distance from the meter. Also, how are the two panels grounded together? they need to be regardless of intent at install as there is only one ground run with the feeders (which is wrong no matter what I think as sub-panels must have a ground run with the feeders.)
    NO I DID NOT SAY SUB-PANEL, THESE ARE MAIN PANELS NO DISCONNECT AT METER. ONLY PANEL A IS GROUNDED- PANEL B IS NOT- THESE PANELS ARE MAIN PANELS-THEY DO HAVE NEUTRAL AND GROUNDS ON SEPARATE BUS BARS, BUT STILL ARE BONDED TOGETHER


  14. #14
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Jerry Peck View Post
    Two ground rods are not required, and the minimum separation between ground rods is 6 feet, not 8 feet.

    And it is better (And accurate) to think in terms of "service equipment" panel(s) and "other than service equipment" panel(s).

    What is a "main" panel? It is not necessarily, but could be, the "service equipment" panel(s).
    I love how you think Jerry. It always makes me smile as I miss my days as a mil spec inspector and mfg engineer. Around here we have always used two ground rods and generally 8 ftish apart, 6 ft being minimum, but you are correct. Every EC I worked for has always used 8 ft.
    We had an apartment complex with all kinds of issues electrically (only 2 years old). Somehow the AHJ and or Electrical Gurus decided that all grounds needed tested. Almost every ground was outside of allowed resistance range. Testing was a b*** as almost every ground rod was actually buried during landscaping and the conductor was in PVC to the ground then buried also. Three point testing proved resistance was high on virtually ALL systems. Some had lost the conductor to the second rod as well.
    We had to reset every ground electrode and clean and bond the grounding conductors at every panel and electrode. We left conductors exposed at the electrodes instead of buried. At least the next time someone can find them.
    The only worse problem is new meter banks that have not had the internal ground and neutral busses re-tightened (torque checked) when installed. Really crazy things (funny and scary) can begin to happen then. Seen that a few times lately.


  15. #15
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    Default Re: 2 main panels (only 1 has a ground)

    Dirk,

    I always recommend 8 ft between ground rods when ground rods are used.

    The reason is simple and easily understood.

    Example:

    Me: Mr. Electrical Contractor, did you measure how far apart the ground rods are?
    EC: No, Why?
    Me: They are only 5'11" apart, inside of rod to inside of rod.
    EC: And you're going to fail me for that 1"?
    Me: Already did.
    EC: (10 minutes of arguing and complaining)
    Me: I will tell you an easy way to not have that happen again if you'd like?
    EC: TELL ME! (followed by an under their breath 'you a-hole')
    Me: Set one ground rods, lay the other ground rod with the top touching the first ground rod, now lift the top if the second rod vertical so it sets on its point - THAT is where you want to drive the second rod. Miss it by some getting the rod starred and you are still more than 6' from the first rod.
    EC: So I'll do that from now on. And I don't have to fix this one?
    Me: I don't recall saying that last part.
    EC: (some under the breath name calling as I walk away)
    Me: (turning around briefly) And don't forget to call in a re-inspection.

    Jerry Peck
    Construction/Litigation/Code Consultant - Retired
    www.AskCodeMan.com

  16. #16
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Jerry Peck View Post
    Please clarify what you mean be "you" and "do not go into the house more than 5-feet".



    Not necessarily.



    That may be a practice in your area, if so, then that piece of copper tubing would have to be connected to an underground metallic water pipe to be of any use, and then that use would only be as a connection to the metallic underground water pipe, if that is even metal (I suspect that most are PVC or some other plastic material instead of metallic in the last several decades, maybe some places are still using copper water service lines?).



    To clarify "water bond": you are not saying that the "water" is bonded, you are only using "water bond" to indicate metallic water piping", correct?
    Jerry you are correct , the house I live in that was built in 1923 used to have waterline grounds, but all the pipe in the house is now PEX and DWV is PVC, the run to the water meter 50ft away by the road is PEX. I do have the 2 ground rods that were driven and megged and an additional ground rod at the garage that has a 200amp panel. Things are different in WV. Especially driving ground rods as we have a little rock in the area. (lots of rock ,m the whole place is rock)


  17. #17
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Richard Bushong View Post
    Jerry you are correct , the house I live in that was built in 1923 used to have waterline grounds, but all the pipe in the house is now PEX and DWV is PVC, the run to the water meter 50ft away by the road is PEX. I do have the 2 ground rods that were driven and megged and an additional ground rod at the garage that has a 200amp panel. Things are different in WV. Especially driving ground rods as we have a little rock in the area. (lots of rock ,m the whole place is rock)
    Why would you Meg 2 ground rods? If a single rod tests at 25Ω you only need 1 rod. If greater, you drive a second rod, hook it up, and walk away. With 2 rods the NEC doesn't care what it tests at (and frankly, the voltages a grounding electrode is meant to deal with doesn't either)

    Why does the garage only have one ground rod?

    Occam's eraser: The philosophical principle that even the simplest solution is bound to have something wrong with it.

  18. #18
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    Default Re: 2 main panels (only 1 has a ground)

    Quote Originally Posted by Bill Kriegh View Post
    Why would you Meg 2 ground rods? If a single rod tests at 25Ω you only need 1 rod. If greater, you drive a second rod, hook it up, and walk away. With 2 rods the NEC doesn't care what it tests at (and frankly, the voltages a grounding electrode is meant to deal with doesn't either)

    Why does the garage only have one ground rod?
    Just habit from driving ground rods for equipment grounding on poles when I was a lineman, we megged each and everyone. Honestly don't know why except in areas that were solid rock. As far as the garage I was getting ready to drive it when the inspector showed up early by a day and he said I didn't need it , so who am I to argue. How would we have any fun if we knew all the answers.


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