Wondering if someone can look at my grounding

rdhem2 said:
Good Sir:
From the pictures in your post of the sub panel in your shed you need to move a few wires. Get a separate ground bar from SqD. It will look just like the neutral bar sans the insulating block. Screw this ground bar directly to the box. Scraping paint off the box where the bar lands is good practice also. Now move all the bare wires from the neutral bar to the ground bar. Include the big green wire, where ever it comes from. Check to see that there is NOT a screw going through the neutral bar into the enclosure. If there is, remove it. This is what is called the neutral bonding screw and should only be installed in a main service entrance panel. All other places the grounds and neutrals must be kept isolated from each other.


Have FUN, be SAFE!
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His shed is a seperate building. That means that the panel in it is the building service entrance and must be bonded and grounded, with its own ground rod. He should not remove the bonding screw.
 
Check 250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s)
I don't want to quote what may be copyrighted material but that isn't always the case. If there is a ground run with the feeders then it is not bonded to the neutral at the remote building and is required to have a grounding electrode at the building. There are few exceptions if the feeder was installed under previous versions of the code without a grounding conductor.
250.32 (B)(1) now require a grounding conductor to be installed with the feeder.
NFPA 2011 Latest version I have at home.

I can't tell from the pictures which way his panel is fed.
 
John Hasler said:
His shed is a seperate building. That means that the panel in it is the building service entrance and must be bonded and grounded, with its own ground rod. He should not remove the bonding screw.
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John--if he is bringing in a neutral from his main panel(near meter) it is a sub panel--- then I would not connect it or bond it with the grounds--neutral bar should not be bonded and ground wires should be on separate bar---Dave
 
jim18655 has it nailed. Perfect reference too. I was and still am under the assumption that the shed's panel is a sub panel fed from the house main service entrance panel. Why would you separate the grounds and neutrals then leave the bonding screw installed? Where is the power company metering located? The first disconnecting means after the metering equipment is considered the main service entrance gear.

The latest code interpretations say you must include a ground wire in the run to a separate building and also drive two ground rods not closer than six feet apart. That is the way the lords of Washington State enforce it. So may it be!

I don't write this stuff I only read it and try to understand it. As Dad always said "The code is a book written by lawyers for lawyers to understand. Just learn to use it, but don't waste your time trying to memorize it, because in a couple years they will change it anyway."

You may disregard me but pay attention to jim18655.

Stay safe, have fun.
 
John Hasler said:
Quoting a brief passage to illustrate a point is fair use. See http://en.wikipedia.org/wiki/Fair_use
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250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s). (A) Grounding Electrode. Building(s) or structure(s) supplied by feeder(s) or branch circuit(s) shall have a grounding electrode or grounding electrode system installed in accordance with Part III of Article 250. The grounding electrode conductor(s) shall be connected in accordance with 250.32(B) or (C). Where there is no existing grounding electrode, the grounding electrode(s) required in 250.50 shall be installed. Exception: A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non–current-carrying metal parts of equipment. (B) Grounded Systems. (1) Supplied by a Feeder or Branch Circuit. An equipment grounding conductor, as described in 250.118, shall be run with the supply conductors and be connected to the building or structure disconnecting means and to the grounding electrode(s). The equipment grounding conductor shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The equipment grounding conductor shall be sized in accordance with 250.122. Any installed grounded conductor shall not be connected to the equipment grounding conductor or to the grounding electrode(s). Exception: For installations made in compliance with previous editions of this Code that permitted such connection, the grounded conductor run with the supply to the building or structure shall be permitted to serve as the ground-fault return path if all of the following requirements continue to be met: (1) An equipment grounding conductor is not run with the supply to the building or structure. (2) There are no continuous metallic paths bonded to the grounding system in each building or structure involved. (3) Ground-fault protection of equipment has not been installed on the supply side of the feeder(s). If the grounded conductor is used for grounding in accordance with the provision of this exception, the size of the grounded conductor shall not be smaller than the larger of either of the following: (1) That required by 220.61 (calculation for neutral size) (2) That required by 250.122 (Table 250.122 Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment) 250.32(C) refers to ungrounded systems ( not applicable here)
 
They've changed it. The very old version I have available makes it clear that a panel in an outbuilding was to be treated as the service entrance to that building (and grounding conductors were not to be run between buildings). The new version is clear as mud.
 
John Hasler said:
They've changed it. The very old version I have available makes it clear that a panel in an outbuilding was to be treated as the service entrance to that building (and grounding conductors were not to be run between buildings). The new version is clear as mud.
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1999 and earlier versions allowed either way. If you didn't run a ground, such as an overhead tri-plex, it was considered a service and service rules applied. If you ran a branch circuit then it was a sub-panel. We still don't know how his panel is fed and which connection would be correct.
 
In 1975 and 76 I taught NEC at a vocational college along with motor relay control. After nearly 40 years as an electrician working with NEC I have found it to be confusing and contradicting. (maybe I am just getting old)
Usually you end up doing what the electrical inspector requires for your location.

Good post jim18655

Ray
 
rdean said:
In 1975 and 76 I taught NEC at a vocational college along with motor relay control. After nearly 40 years as an electrician working with NEC I have found it to be confusing and contradicting. (maybe I am just getting old)
Usually you end up doing what the electrical inspector requires for your location.

Good post jim18655

Ray
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Nothing I do ever gets inspected (inspectors are thin on the ground in our rural jurisdiction) and I have confidence in my engineering judgement so I treat the code as a standard, not a law. It's useful for that. When I worked at Univ. of Mich. Hospital the code was an important reference but it often didn't apply. When it comes to grounding I've always relied on the IEEE Green Book.
 
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