Objectionable Current- Hazzard?

Specific Inspection Topics Electrical Inspections
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http://www.mikeholt.com/onlinetraining/page_images/1113844669_2.jpg

(A) Preventing Objectionable Current. To prevent a fire, electric shock, or improper operation of circuit-protection devices or sensitive equipment, electrical systems and equipment must be installed in a manner that prevents objectionable current from flowing on conductive materials, electrical equipment, or grounding and bonding paths.

Author’s Comment: Objectionable current occurs because of improper neutral-to-case bonds and wiring errors.Improper Neutral-to-Case Bond [250.142]

Panelboards. Objectionable current will flow on metal parts when the grounded neutral conductor is bonded to the metal case of a panelboard that is not part of service equipment.

Disconnects. Objectionable current will flow on metal parts when the grounded neutral conductor is bonded to the metal case of a disconnecting means that is not part of service equipment.

Separately Derived Systems. Objectionable current will flow on metal parts when the grounded neutral conductor is bonded at the transformer as well as to the metal case on the load side of the transformer.

Pauls Comments- Guys this is why you make sure their is NOT the potential for this…this is WHY sub-panels need to have a floating neutral and why bonding when using metal conduit is VERY important…We will simply PASS over the SDS comments…Way to technical…lol

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This brings up an interesting paradox. The code says the main bonding jumper shall be in the service disconnect enclosure and the utility bonds the neutral in their service equipment.
The accepted installation here is a PVC raceway between the panel and the meter base or an SE cable.

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Yes it does Greg…And it has been widly debated on MANY forums as I am sure you are aware of and might have partaken in them…lol…

I most certainly agree…to remove the potential of issues PVC is the best course of action to take…as well with SE which I actually prefer more.

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Bump- Guys this is important stuff…:slight_smile: you look for it everytime you open a sub-panel…:slight_smile:

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I understand Paul. It is important.

“Pauls Comments- Guys this is why you make sure their is NOT the potential for this…this is WHY sub-panels need to have a floating neutral and why bonding when using metal conduit is VERY important…We will simply PASS over the SDS comments…Way to technical…lol”

Are you now saying that conduit, EMT, etc is important? Is the connection of ROMEX ground wire sufficient or not.

Gee, maybe Chicago has something here? :mrgreen:

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Actually the metal conduit on a service is the PROBLEM, not the solution.

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Agreed…Greg…

Actually, william it is important in EVERY meaning when it comes to Objectionable Current…Romex is no different if installed incorrectly.

lol…Mr.Will…cut me some slack fella…lol :)…the reason Mike Holt uses Conduit and I like the images is because it is easier to explain objectionable current and bonding with metal piping images…

However the same still applies in the image above the pipe one if you install a Sub-Panel incorrectly…

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Paul;

lol… No problem, guy… lol (really)… I am just pulling your chain… lol… BTW… The chain is to a light fixture and is insulated,… lol, given the new NEC rules… lol… that, no doubt… lol… Mr. Tedesco will soon quote… lol…

Hpe this…lol … helps.

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lol…I know ya waz…playin Mr. Decker…I dont mind at all…Keep me on my toes no doubt…:slight_smile:

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Bump…great for the newbies…:slight_smile:

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Cool…

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Bumping it…becasue Mr. Decker likes to TEASE me…

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This is why the egc, electrode groding conductor, must be connected within 5’, when the water line is metal, of the water line entering the structure.

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Hi Will

The first thing that came to my mind was the insulator between the chains that was required by the code long ago that looked like the one here.

Knob-N-Tube Ceiling Lamp

If I had my way I would use Fiber Glass Conduit for service entrance raceways, Type E? I believe, Greg brings up a good point and Mike Parks too although there is much more that was submitted with the proposal to add restrictions for the 5 foot distance, etc.