Sub-panel bonding ?

[fnewman (Frank P. Newman)]

Am I missing something?.. It is common around here for the main service panel to be mounted outside next to the meter (even if it only has only one breaker - the main disconnect). That one is usually wired correctly. Then, four conductors are routed to the interior distribution sub-panel. Most of the time I find that the strap between the neutral and ground busses has been properly removed (and generally remove the few I find). However, I also commonly find that the electrician has not installed, or has removed, the bonding screw that will bond the panel itself to the ground bus. Do I need to carry green screws in my pocket too (or they not required)? :mrgreen:

[dokeefe (David OKeefe, Lic. # 16000038229)]

I am wondering why you are removing anything at all. Do you correct other defects you find during an inspection.

[fnewman (Frank P. Newman)]

Sure - a lot of inspectors correct minor defects that they observe (and are qualified to do) as a service to the homeowner.

[jjonas (Jeffrey Jonas)]

@fnewman

Sure - a lot of inspectors correct minor defects that they observe (and are qualified to do) as a service to the homeowner.

Me’thinks this is going to get very interesting…

[fnewman (Frank P. Newman)]

Could be - maybe a poll would be insteresting; but for now I’d like to see some discussion on the original topic.

[ccurrins (Christopher Currins, CMI)]

@fnewman

However, I also commonly find that the electrician has not installed, or has removed, the bonding screw that will bond the panel itself to the ground bus. Do I need to carry green screws in my pocket too (or they not required)? :mrgreen:

Not trying to be a smart a**, but helpful. If you have to ask this question apparently you’re not qualified to be tampering with someone else’s electrical service and may be setting yourself up for future problems. Also I doubt your insurance carrier approves of this method.

Personally there is no way, as an inspector, I would remove, or install, a bonding strap are screw.

[fnewman (Frank P. Newman)]

Actually, I don’t make a habit of making many corrections to anything (just stirring the pot a bit :-)), but may if there is only one small item that is in need. I think sometimes inspectors do know the answers to the questions they ask, but may wonder about the work of the “qualified” people whose work they have to inspect when they see the same defects over and over again.

[rmeier2 (Robert Meier)]

How can the ground bar in the subpanel not be connected to the panel frame? Usually they come with two screws.

[fnewman (Frank P. Newman)]

@Robert_Meier

How can the ground bar in the subpanel not be connected to the panel frame? Usually they come with two screws.

Some do, for sure, but some brands (like the one I saw today) appeared to be mounted on insulated material. Otherwise, why would there be any need for a dedicated screw hole for bonding. For example, here is a picture of a sub-panel where neutral and ground busses are improperly connected together.

[rmeier2 (Robert Meier)]

@fnewman

Some do, for sure, but some brands (like the one I saw today) appeared to be mounted on insulated material. Otherwise, why would there be any need for a dedicated screw hole for bonding. For example, here is a picture of a sub-panel where neutral and ground busses are improperly connected together.

Got it, that would be the neutral bar on both sides of the panel in a service. Since it’s set up as a subpanel the bonding jumper between the two bars should have been removed. I was thinking of a separate grounding bar in a subpanel.

[bstenger (Bill T. Stenger)]

For those that are not qualified (in some states or areas means unlicensed) I hope for your sake that u don’t mention anything u do to “help the customer” If something happens the lawyers would blame you even if your “correction” was right or wrong. As a former Elec. cont. I would resent it if someone took it upon themself to make me look bad in order to boost their ego. As an Elec. Inspector, it is unlawful to make any sort of correction to anything. As a home inspector we are there to note any problem and refer to those that are moreso qualified.
All sub-panels downstream of the 1st panel with the main breaker is to have the forth wire (equipment ground) bonded to the panel, (with exception) If a circuit or feeder is installed to an out building and there is no metallic connection then a seperate equip. gnd. need not be installed. (per N.E.C.)Simply treat the install as a service, drive ground rod or whatever the local AHJ requires.
As always, when in doubt, (P.Your.A).

Be Careful, your family needs you
Bill S

[rmeier2 (Robert Meier)]

@bstenger

For those that are not qualified (in some states or areas means unlicensed) I hope for your sake that u don’t mention anything u do to “help the customer” If something happens the lawyers would blame you even if your “correction” was right or wrong. As a former Elec. cont. I would resent it if someone took it upon themself to make me look bad in order to boost their ego. As an Elec. Inspector, it is unlawful to make any sort of correction to anything. As a home inspector we are there to note any problem and refer to those that are moreso qualified.
All sub-panels downstream of the 1st panel with the main breaker is to have the forth wire (equipment ground) bonded to the panel, (with exception)** If a circuit or feeder is installed to an out building and there is no metallic connection then a seperate equip. gnd. need not be installed. (per N.E.C.)Simply treat the install as a service, drive ground rod or whatever the local AHJ requires. **
As always, when in doubt, (P.Your.A).

.

Be Careful, your family needs you
Bill S

Bill this is no longer permitted under the 2008 NEC.

[bstenger (Bill T. Stenger)]

Bill this is no longer permitted under the 2008 NEC.
Hi Robert,
Please read art. 250.32 (B) Exception (1) (2) (3)existing structures of the 2008 nec, which says u can have a 3 wire sys. 250.32 (A) “Where there is no existing grounding electrode sys. follow 250.50.”

We are always learning
Bill S

[rmeier2 (Robert Meier)]

@bstenger

Bill this is no longer permitted under the 2008 NEC.
Hi Robert,
Please read art. 250.32 (B) Exception (1) (2) (3)existing structures of the 2008 nec, which says u can have a 3 wire sys. 250.32 (A) “Where there is no existing grounding electrode sys. follow 250.50.”

We are always learning
Bill S

Yes, I was referring to new installations under the 2008 NEC. The 2005 and some earlier code versions permitted the grounded conductor to be used for grounding at a remote building when all of the conditions in 250.32(B)(2) were met. 250.32(B)(2) has been removed from the 2008 NEC and is now 250.32(B). The current wording no longer gives permission to use the grounded conductor for grounding. Under the 2008 NEC it is only permitted for existing installations. Here’s the new wording:

250.32(B) Grounded Systems. For a grounded system at the separate building or structure, 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 existing premises wiring systems only, the grounded conductor run with the supply to the building or structure shall be permitted to be connected to the building or structure disconnecting means and to the grounding electrode(s) and shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded where all the requirements of (1), (2), and (3) are 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).
Where 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: