harborrick
Member
- Location
- Irvine California
Today I was called on running 2.1/2" conduit about 100 feet without ground wire in the City of Gardena,CAlifornia.This feeds 200 amp 3 phase 4 wire service.
E.M.T Conduit for Ground
- Thread starter harborrick
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: E.M.T Conduit for Ground
Perhaps there is a city or state rule on this subject? Did the person who "called you" on this issue give you the code article that was being cited?
Perhaps there is a city or state rule on this subject? Did the person who "called you" on this issue give you the code article that was being cited?
charlie
Senior Member
- Location
- Indianapolis
Re: E.M.T Conduit for Ground
If this feeds a service, I assume you mean service equipment. If that is the case, you are discussing service entrance conductors and you would not need a grounding conductor anyway even if it were PVC conduit.
If this feeds a service, I assume you mean service equipment. If that is the case, you are discussing service entrance conductors and you would not need a grounding conductor anyway even if it were PVC conduit.
sandsnow
Senior Member
- Location
- Southern California
Re: E.M.T Conduit for Ground
It wouldn't by chance have anything to do with the locknuts or EMT connectors not suitable for grounding, would it? If so there is a thread here and on that "other forum" as it's refered to here.
http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=7;t=001141
http://electrical-contractor.net/ubb/Forum1/HTML/005053.html
It wouldn't by chance have anything to do with the locknuts or EMT connectors not suitable for grounding, would it? If so there is a thread here and on that "other forum" as it's refered to here.
http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=7;t=001141
http://electrical-contractor.net/ubb/Forum1/HTML/005053.html
harborrick
Member
- Location
- Irvine California
Re: E.M.T Conduit for Ground
Thanks for you replies.
I asked him what year code book the City was currently using and he said 1999.I looked into art250.118 and their was my answer.I went to the building department and photocopied it and left him a message to call me.
He just said one of his other inspectors told him it was required.No issues on bonding locknuts.
The emt run was feeding a 200 amp sub panel from main disconnect.
Thanks Rick
Thanks for you replies.
I asked him what year code book the City was currently using and he said 1999.I looked into art250.118 and their was my answer.I went to the building department and photocopied it and left him a message to call me.
He just said one of his other inspectors told him it was required.No issues on bonding locknuts.
The emt run was feeding a 200 amp sub panel from main disconnect.
Thanks Rick
sandsnow
Senior Member
- Location
- Southern California
Re: E.M.T Conduit for Ground
Rick
I applaud you for trying to learn the code. An inspector who does not try and do the same is not doing his job. The inspector in question is being lazy by just going by what another inspector said to do.
I hope it works out in your favor
Rick
I applaud you for trying to learn the code. An inspector who does not try and do the same is not doing his job. The inspector in question is being lazy by just going by what another inspector said to do.
I hope it works out in your favor
physis
Senior Member
Re: E.M.T Conduit for Ground
Edit: If some of those discussions could get to the CMP's.
[ December 02, 2004, 12:30 PM: Message edited by: physis ]
That's a good trick. The rarest reaction I get to quoting a code to an inspector is that he actually read it. I think it would be like admitting not knowing it.
Edit: If some of those discussions could get to the CMP's.
[ December 02, 2004, 12:30 PM: Message edited by: physis ]
harborrick
Member
- Location
- Irvine California
Re: E.M.T Conduit for Ground
Well this mourning he called and appoligised.He said he went and read the article when he got home.He was very nice about it.I also gave him some advise on bonding.
I always practice getting along with any inspector.I have been in business for 17 years and have never argued with one.May not always agree.
Most have pretty common sense and are just trying to do their job.Never get on their bad side or try to show them up.
Thanks Rick
Well this mourning he called and appoligised.He said he went and read the article when he got home.He was very nice about it.I also gave him some advise on bonding.
I always practice getting along with any inspector.I have been in business for 17 years and have never argued with one.May not always agree.
Most have pretty common sense and are just trying to do their job.Never get on their bad side or try to show them up.
Thanks Rick
charlie
Senior Member
- Location
- Indianapolis
Re: E.M.T Conduit for Ground
Some do, Sam.If some of those discussions could get to the CMP's.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Re: E.M.T Conduit for Ground
I would like to discuss this a bit further, not necessarily this specific installation, but the use of emt as the EGC in general. Although the code permits emt and RMC as equipment grounding conductors, there is a statement in the code which implies that this practice is not always appropriate. 250.4(A)(5) in short states there must be an effective low impedance ground fault path. The commentary on 250.133(A) in the handbook states, "if a long distance exists between a power source and utilization equipment, some of the wiring methods allowed for grounding purposes must be evaluated further." I guess this just equates to a judgment call of the electrician and/or inspector as to whether a EGC should be installed in emt? Anyone have any opinions on this? In the past i have always installed a EGC in emt. Its kind of like the push in terminals on receptacles, you can use them but do you want to or should you?
I would like to discuss this a bit further, not necessarily this specific installation, but the use of emt as the EGC in general. Although the code permits emt and RMC as equipment grounding conductors, there is a statement in the code which implies that this practice is not always appropriate. 250.4(A)(5) in short states there must be an effective low impedance ground fault path. The commentary on 250.133(A) in the handbook states, "if a long distance exists between a power source and utilization equipment, some of the wiring methods allowed for grounding purposes must be evaluated further." I guess this just equates to a judgment call of the electrician and/or inspector as to whether a EGC should be installed in emt? Anyone have any opinions on this? In the past i have always installed a EGC in emt. Its kind of like the push in terminals on receptacles, you can use them but do you want to or should you?
- Location
- Massachusetts
Re: E.M.T Conduit for Ground
I believe a properly installed metal raceway system may provide a lower impedance ground fault path than the EGC required by Table 250.122.
I believe a properly installed metal raceway system may provide a lower impedance ground fault path than the EGC required by Table 250.122.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: E.M.T Conduit for Ground
I had a thread going on this very subject that got fairly interesting. It is here:
http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=11;t=003251#000000
I had a thread going on this very subject that got fairly interesting. It is here:
http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=11;t=003251#000000
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Re: E.M.T Conduit for Ground
Ryan, thanks for the great link, certainly lots of great discussion there i will mull over.
A while back i was helping a friend set up a hot wire foam cutting jig to "plane down" some 3" foam. Just off the top of my head without doing any calculations, i was sceptical that my variable voltage dc power supply could be adjusted low enough to prevent the power supply from 'seeing' the load, a two foot piece of wire, as a short. It turned out that the steel was such a bad conductor compared to copper that i barely had enough voltage to push a good 20 amps thru. I guess thats why i am initially hesitant to use emt as EGC. I will mull over that link and do some calculations and hopefully i can become a bit more comfortable with it.
Ryan, thanks for the great link, certainly lots of great discussion there i will mull over.
A while back i was helping a friend set up a hot wire foam cutting jig to "plane down" some 3" foam. Just off the top of my head without doing any calculations, i was sceptical that my variable voltage dc power supply could be adjusted low enough to prevent the power supply from 'seeing' the load, a two foot piece of wire, as a short. It turned out that the steel was such a bad conductor compared to copper that i barely had enough voltage to push a good 20 amps thru. I guess thats why i am initially hesitant to use emt as EGC. I will mull over that link and do some calculations and hopefully i can become a bit more comfortable with it.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: E.M.T Conduit for Ground
Yes, I was very happy with the way that discussion took off running. I would make it point to click the link in that thread that Don provided to the GEMI software. I learned quite a lot just by playing around with it.
Yes, I was very happy with the way that discussion took off running. I would make it point to click the link in that thread that Don provided to the GEMI software. I learned quite a lot just by playing around with it.
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