bonding
- Thread starter rjdad82
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: bonding
250.148
250.148
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
I have not heard of that?
If EMT connectors ar listed for grounding and EMT is allowed to be the EGC why would we have to bond at a juntion box? 250.148 is only if there will be a device or equipment mounted to or in a box. If the box is only for the means of a juntion point then I have never heard of haveing to bond each box?
I have not heard of that?
If EMT connectors ar listed for grounding and EMT is allowed to be the EGC why would we have to bond at a juntion box? 250.148 is only if there will be a device or equipment mounted to or in a box. If the box is only for the means of a juntion point then I have never heard of haveing to bond each box?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: bonding
This was a change for the 2002 nec. it no longer requires bonding to a jbox if the conductors are pulled thru without splice or device, when an EGC is used.
This was a change for the 2002 nec. it no longer requires bonding to a jbox if the conductors are pulled thru without splice or device, when an EGC is used.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
Tom if you pull an EGC into a J-box to split up and feed sevral receptacles why would need to bond this J-box that is bonded by the EMT?
Tom if you pull an EGC into a J-box to split up and feed sevral receptacles why would need to bond this J-box that is bonded by the EMT?
Re: bonding
we must also look in the 250.148(a)in the 2002 code which says that a connection shall be made between the one or more equipment grounding conductors and a metal box by means of a grounding screw that shall be used for no other purpose or a listed grounding device. The only exception would be 250.146(d) for isolated ground receptacles and non-metallic boxes.
we must also look in the 250.148(a)in the 2002 code which says that a connection shall be made between the one or more equipment grounding conductors and a metal box by means of a grounding screw that shall be used for no other purpose or a listed grounding device. The only exception would be 250.146(d) for isolated ground receptacles and non-metallic boxes.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
I totally agree if a J-box was used with a Non-Metallic type race-way But the starter of the thread stated :
EMT is allowed to bond the box as per: 358.60
The only time I'm aware of haveing to bond across a J-box is when it incloses a GEC required in 250.64(E)
I'm I missing somthing?
[ October 15, 2004, 07:29 PM: Message edited by: hurk27 ]
I totally agree if a J-box was used with a Non-Metallic type race-way But the starter of the thread stated :
Which would only require a bond if there was a device or equipment installed in the box and the method of connecting the device didn't meet the requirment's of 250.146(A)-(D)
EMT is allowed to bond the box as per: 358.60
The only time I'm aware of haveing to bond across a J-box is when it incloses a GEC required in 250.64(E)
I'm I missing somthing?
[ October 15, 2004, 07:29 PM: Message edited by: hurk27 ]
Re: bonding
I think that you might be confusing 358.60, it does state that emt maybe used as a grounding conductor, though i think that it is referring back to 250.52(a)(5) where 3/4 or more may be used for a grounding electrode for services. Maybe we should consider eccentric and concentric knockouts that are not a continuous bond accept where listed for the purpose as per 250.97Ex. what do you think?
I think that you might be confusing 358.60, it does state that emt maybe used as a grounding conductor, though i think that it is referring back to 250.52(a)(5) where 3/4 or more may be used for a grounding electrode for services. Maybe we should consider eccentric and concentric knockouts that are not a continuous bond accept where listed for the purpose as per 250.97Ex. what do you think?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
rjdad82
First there is only one place in the NEC that require bonding around eccentric and concentric knockouts 250.92(B). Which is only for service's,
And 250.64(E) requires to bond across all J-box's
250.97 which is only for circuits over 250 volts to ground, Which in 250.97 exception (c) even states that EMT connectors are allowed for grounding.
rjdad82
First there is only one place in the NEC that require bonding around eccentric and concentric knockouts 250.92(B). Which is only for service's,
And 250.64(E) requires to bond across all J-box's
250.97 which is only for circuits over 250 volts to ground, Which in 250.97 exception (c) even states that EMT connectors are allowed for grounding.
physis
Senior Member
Re: bonding
I might be in left field on this but I'm gonna take a stab at it. I think what the point is, is when you introduce a "forein" ground (just a convenient term I made up). One that comes from over there. And you use it over here. Say in your EMT run. You bond the two grounds together. I think what's behind it is to keep two different grounding systems from developing.
When I populate boxes ALL the EGC's go together.
250.148(A) Doesn't say you need an EGC to bond to the box. It says if you have one it needs to be bonded to the box.
Am I seeing what you guys are saying the right way?
I might be in left field on this but I'm gonna take a stab at it. I think what the point is, is when you introduce a "forein" ground (just a convenient term I made up). One that comes from over there. And you use it over here. Say in your EMT run. You bond the two grounds together. I think what's behind it is to keep two different grounding systems from developing.
When I populate boxes ALL the EGC's go together.
250.148(A) Doesn't say you need an EGC to bond to the box. It says if you have one it needs to be bonded to the box.
Am I seeing what you guys are saying the right way?
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
what I don't see is the requirement in 250.148 to re-bond a box that is NEC compliantly bonded by the EMT. 250.148 even say's:
It even say's "joined (spliced) within the box" OR "to the box"
The heading of this section even tell us what is the meaning of this section
What it is saying is this is how we are to ensure a low impedance path for fault current. which ether the conduit or the EGC is more than capable of doing each by it's self. EMT is UL listed for grounding.
Maybe someone could show me why this doesn't mean this?
what I don't see is the requirement in 250.148 to re-bond a box that is NEC compliantly bonded by the EMT. 250.148 even say's:
Look at the words "OR" in between each method of connection. OR means we can do it ether way.
It even say's "joined (spliced) within the box" OR "to the box"
The heading of this section even tell us what is the meaning of this section
This does not say methods of box bonding?
What it is saying is this is how we are to ensure a low impedance path for fault current. which ether the conduit or the EGC is more than capable of doing each by it's self. EMT is UL listed for grounding.
Maybe someone could show me why this doesn't mean this?
- Location
- Illinois
- Occupation
- retired electrician
Re: bonding
Hurk,
I agree that the code wording is poor and does not convey the CMPs intent, but what about 240.148(A)? It seems to always require the one or more EGCs to be connected to the box.
Don
Hurk,
I agree that the code wording is poor and does not convey the CMPs intent, but what about 240.148(A)? It seems to always require the one or more EGCs to be connected to the box.
In this case I don't think that the "or" permits you to just connect the EMT to the box.
Don
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
I agree with you that the wording is confusing at best. This is one reason I would love to build a book that will try to totally capture the CMP's intent (whether right or wrong) at the time of writing a code. It would be the ultimate in a NEC hand book.
But what I don't see is what danger is there not bonding this EGC to a box when there is another UL listed grounding method already installed. As we know there is no danger with an isolated grounding conductor and it is allowed to pass without connection to these box's? I just can't see the intent as you said the writing is vague.
I agree with you that the wording is confusing at best. This is one reason I would love to build a book that will try to totally capture the CMP's intent (whether right or wrong) at the time of writing a code. It would be the ultimate in a NEC hand book.
But what I don't see is what danger is there not bonding this EGC to a box when there is another UL listed grounding method already installed. As we know there is no danger with an isolated grounding conductor and it is allowed to pass without connection to these box's? I just can't see the intent as you said the writing is vague.
- Location
- Illinois
- Occupation
- retired electrician
Re: bonding
hurk,
Don
hurk,
That already exists...the ROPs and ROCs have that information.
Don
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: bonding
Yes that is true But can we get it in a single book that would include each and every one for every code? It's hard to do research on the road.
It Could be called " The history Of the Changes To The NEC" I think it would be a best seller for the NFPA.
Yes that is true But can we get it in a single book that would include each and every one for every code? It's hard to do research on the road.
It Could be called " The history Of the Changes To The NEC" I think it would be a best seller for the NFPA.
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