Full Size EGC

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mbrooke said:
Here are what some EEs say about it:

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I would take their advice and forget about the Z of conduit, but I only care about it in that if a knicked hot touched conduit between two j-boxes that the breaker actually clear.
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This steel tube institute posted studies in one of our trade rags quite a while ago, the gist being how any given fault travels back to 'source'

Obviously they were advocating their product

~RJ~
 
I keep running into forklift drivers that have torn the heck out of even properly tightened and secured conduits to the point of hole in the wall that have destroyed any effective ground fault path that used to exist leaving potentially isolated parts. The conductors are the only things stopping the conduit from falling.
 
jimport said:
I keep running into forklift drivers that have torn the heck out of even properly tightened and secured conduits to the point of hole in the wall that have destroyed any effective ground fault path that used to exist leaving potentially isolated parts. The conductors are the only things stopping the conduit from falling.
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First, that's not really a problem with the conduit is it? Second, if there really is isolated parts then my scenario describing a isolated piece of conduit with a bare hot conductor faulted to it shows how the extra green wire doesn't do anything to help clear the fault.
 
mbrooke said:
Bummer :( Makes no sense though.
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Well in the case of your welder outlet, the 3/4" flex is not a EGC, so if the receptacle is mounted on a 4S industrial raised cover and someone opens the cover, the 4S box is floating (becomes un-bonded.) You need a 10/32 ground screw and a lay in
For the full size EGC.
layIN.png
 
tortuga said:
Well in the case of your welder outlet, the 3/4" flex is not a EGC, so if the receptacle is mounted on a 4S industrial raised cover and someone opens the cover, the 4S box is floating (becomes un-bonded.) You need a 10/32 ground screw and a lay in
For the full size EGC.
View attachment 2556338
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And if you bond the EGC to the box a bonding jumper to the receptacle is not required.
 
ActionDave said:
I never said it was. And it doesn't change anything about you being wrong about the reliability of green wires as a fault path or the fact that you have little or perhaps no real field experience with any kind of wiring.
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If you had field experience with wiring you'd know that a properly made wire nut or screw terminal is a cold weld. You'd know that the impedance of an EGC is listed in Chapter 9 Table 9 where as not such thing exists for conduit, and you'd know conduit joints (EMT anyway) oxide over time. Let alone loosen.
 
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tortuga said:
Well in the case of your welder outlet, the 3/4" flex is not a EGC, so if the receptacle is mounted on a 4S industrial raised cover and someone opens the cover, the 4S box is floating (becomes un-bonded.) You need a 10/32 ground screw and a lay in
For the full size EGC.
View attachment 2556338
Click to expand...


Is working live really necessary? I mean for one you'll need to unplug the load because you loose its bond back to the X0.
 
electrofelon said:
I have not seen that. I've seen lots of shoddy pipe work for sure, but I also havent seen conduit "pulled out" of fittings. I'm sure it happens now and then, so what? Calm down it's not the end of the world.
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I am calm. Sorry if I come across heated- thats not my intent. :)

You've never seen EMT dull over time?

My point is I have less faith in conduit than I do in wire EGCs.
 
mbrooke said:
1) If someone is taking off the cover the circuit should be de-energized

2) The machine looses its ground in the bond to the box first case.
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In all your field experience you've never known that the box has to be bonded, then a jumper to the receptacle?
 
Little Bill said:
In all your field experience you've never known that the box has to be bonded, then a jumper to the receptacle?
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If the receptacle is self grounding you only need to bond to the box.

However, I can't figure out why it can't be done the other way around. Use the self ground to bond the box.
 
mbrooke said:
If the receptacle is self grounding you only need to bond to the box.

However, I can't figure out why it can't be done the other way around. Use the self ground to bond the box.
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In the case of the photo in the OP a self grounding receptacle is not required for the 4" square cover that is shown neither is a bonding jumper to the box. The cover is permitted to bond the receptacle to the box. Regarding the bold I would guess that the reason is that if the cover is lose then the box is not properly bonded but without the bonding jumper neither is the receptacle.
 
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