Grounding 24x24 box

Status
Not open for further replies.
ActionDave said:
And if you have a box bonded by metallic conduit then you don't need a wire EGC. Agree?
Click to expand...

I just re-read what you said and take back my last post.

I do agree adding a wire type EGC to a metallic conduit system like 90% of the jobs require adds mounds of extra work and confusion.

On that I do agree.

JAP>
 
jap said:
What if a 20 amp circuit was pulled straight through the box and was the only circuit there in the beginning and a #12 EGC was jumper to the box to bond it, then, we came along and pulled a 100 amp feeder straight through that box with a #8 EGC, would we then need to bond the #8 EGC to the box instead of the original #12 bonding since the existing #12 bonding jumper is now not large enough for the 100a Feeder ?
Click to expand...

IIRC, yes, but I'm not going to claim expert status.

But if the conduit satisfies bonding requirements, then no.

I'll await official confirmation from better Code guys than me.
 
The only way to clear up this confusion in my mind would be to require a certain size EGC to be bonded to the box based on the size and material of the box itself.

Bond the box right up front, then, forget about what may or may not be installed in it in the future.

JAP>
 
jap said:
The only way to clear up this confusion in my mind would be to require a certain size EGC to be bonded to the box based on the size and material of the box itself.

Bond the box right up front, then, forget about what may or may not be installed in it in the future.
Click to expand...

Is the intent of the requirement to see that the box is bonded, or to provide the best fault path for the largest source in the box?
 
MAC702 said:
Is the intent of the requirement to see that the box is bonded, or to provide the best fault path for the largest source in the box?
Click to expand...

It would be useless to require a box to be bonded if that bonding was not capable of clearing a fault.

It's said that a metallic raceway such as EMT or Rigid is the best Fault return path you can have.

So, why when you decide to install a wire type EGC inside of it does that fault path seem to fall by the way side?

JAP>
 
MAC702 said:
Is the intent of the requirement to see that the box is bonded, or to provide the best fault path for the largest source in the box?
Click to expand...
I believe what is intended is that every spliced wire egc needs to be tied together and at least one tag to the box.

I also believe 250.148 is not based on anything electrically, logically, reasonable. As long as a box is bonded by a metallic conduit or the largest wire egc present what does it matter about any other green wires that don't get included in the wire nut orgy?
 
MAC702 said:
To clarify, one of the EGC's would have to be spliced and bonded to the box from the beginning, even if none of the CCCs are spliced, right?
Click to expand...
ActionDave said:
And if you have a box bonded by metallic conduit then you don't need a wire EGC. Agree?
Click to expand...
IIRC, you can not install a metallic box in a nonmetallic wiring method... or is it a wire-type EGC must be installed and bonded to the box. Has to be one or the other. :blink:

Apparently, my 'IIRC' is not working correctly at the moment. :?
 
Smart $ said:
IIRC, you can not install a metallic box in a nonmetallic wiring method... or is it a wire-type EGC must be installed and bonded to the box. Has to be one or the other. :blink:

Apparently, my 'IIRC' is not working correctly at the moment. :?
Click to expand...
Hope you are wrong, in a food grade production plant have had many stainless boxes connected to non metallic wiring methods over the past 30 years. Have also had non metallic boxes occasionally connected to metallic wiring methods, if wiring method becomes isolated that is what bonding bushings or other bonding fittings are for.
 
ActionDave said:
I believe what is intended is that every spliced wire egc needs to be tied together and at least one tag to the box.

I also believe 250.148 is not based on anything electrically, logically, reasonable. As long as a box is bonded by a metallic conduit or the largest wire egc present what does it matter about any other green wires that don't get included in the wire nut orgy?
Click to expand...

It matters because we are not always talking about a "New" install like most of the code is based on.

Imagine running a 15 amp circuit through an existing large J-box, splicing that circuit, and then having to cut the largest EGC in that J-box and bond it to the box.

That existing EGC in the J-box may be very large, with no slack, and your sitting there fixing to cut a perfectly good fault return paths and splice all of them in the J-box together , and , put a needless splice in all of them just because you added some #14.

Now, if we only had to bond the EGC that was "associated" with the circuit we just pulled in, and only need splice and bond the #14 EGC to the box without disturbing all of the others, To me, that would seem reasonable but may not be compliant by the confusing way it is worded.

JAP>
 
jap said:
....That existing EGC in the J-box may be very large, with no slack, and your sitting there fixing to cut a perfectly good fault return paths and splice all of them in the J-box together , and , put a needless splice in all of them just because you added some #14.

Now, if we only had to bond the EGC that was "associated" with the circuit we just pulled in, and only need splice and bond the #14 EGC to the box without disturbing all of the others, To me, that would seem reasonable but may not be compliant by the confusing way it is worded.

JAP>
Click to expand...

If there is an existing j box with a large egc not bonded to the box then said box must be bonded by a metallic raceway, if not you have a violation that needs corrected.

If you do have an effectively bonded box then why worry about a 14AWG green wire being connected to the box?
 
ActionDave said:
If there is an existing j box with a large egc not bonded to the box then said box must be bonded by a metallic raceway, if not you have a violation that needs corrected.

If you do have an effectively bonded box then why worry about a 14AWG green wire being connected to the box?
Click to expand...

If you have an existing j box with a large EGC not bonded to the box and no splices in the box then said box seems to be allowed to be bonded by the metallic raceway,

but,

Some are saying that you may only need to bond the largest EGC in the box to the box.

I thought the discussion here was that if there is a splice made in any of the circuits then "all" of the ECG's have to be tied together and bonded to the box, not just the EGC associated with the spliced conductors, which is where things start getting confusing if the #14 green wire was routed into the box and spliced after the original "Large" EGC was installed.

JAP>
 
ActionDave said:
Any spliced egc have to bonded to the box if it's a metal box. Any spliced egc in a non metallic box have to be tied together.
Click to expand...

Which is where the discussion started to the contrary at about post 32 that "All" of the EGC's have to be tied together and a bond made to the box, not just the spliced conductors.

Jap>
 
kwired said:
Hope you are wrong, in a food grade production plant have had many stainless boxes connected to non metallic wiring methods over the past 30 years. Have also had non metallic boxes occasionally connected to metallic wiring methods, if wiring method becomes isolated that is what bonding bushings or other bonding fittings are for.
Click to expand...
MAC702 said:
No NM to metallic boxes?
Click to expand...
I have a vague recollection of a section stating something of the like, or maybe it was no nonmetallic boxes in a metallic wiring method. Maybe it was just my imagination working overtime.

If no one knows of such requirement, please resume normal discussion... :)
 
kwired said:
Hope you are wrong, in a food grade production plant have had many stainless boxes connected to non metallic wiring methods over the past 30 years. Have also had non metallic boxes occasionally connected to metallic wiring methods, if wiring method becomes isolated that is what bonding bushings or other bonding fittings are for.
Click to expand...

Smart $ said:
I have a vague recollection of a section stating something of the like, or maybe it was no nonmetallic boxes in a metallic wiring method. Maybe it was just my imagination working overtime.

If no one knows of such requirement, please resume normal discussion... :)
Click to expand...

314.3 states that nonmetallic boxes are only permitted with certain nonmetallic items including nonmetallic raceways. The exception allows for metal raceways if the box has internal bonding means between all entries.
 
jap said:
In my mind the bonding of the box should not be dependent on whether or not a circuit is spliced in that particular box or not.
The box needs to be bonded regardless of the size of the circuit or the number of circuits spliced inside the box.

Maybe it does say that in one way or the other.

JAP>
Click to expand...
if you installed emt or any other metal conduit then essential the box is bonded,it seems to me the purpose of requiring the egc to bond to a box if spliced is for operation of the ocpd in case that splice comes apart as well as to make a low impedance return path
 
dean4766 said:
if you installed emt or any other metal conduit then essential the box is bonded,it seems to me the purpose of requiring the egc to bond to a box if spliced is for operation of the ocpd in case that splice comes apart as well as to make a low impedance return path
Click to expand...

So you think a perfectly good EGC such as EMT conduit or any other metal conduit wouldn't activate an OCPD if a wire type splice happened to come apart in a J-box ?

I beg to differ.

JAP>
 
to be clear...

I’ve seen many an install where 10 pipes in and 10 pipes out of 4” conduit with 500’s and 1/0 grounds that were spliced that were not bonded to the box at al. Are you saying that these installs were wrong?
 
Status
Not open for further replies.
Top