EMT as ground
- Thread starter jcb250
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: EMT as ground
take a look at 250.118
take a look at 250.118
Re: EMT as ground
British rules require a redundant grounding conductor in all occupancies. Here is northeast Ohio the vast majority of our customers require it as a job specification.
If you have ever had to open up a wall and reconnect an EMT joint like I have you would not be asking this question and you would realize why the British require redundant grounding conductors in all occupancies and not just in hospitals.
[ May 07, 2005, 02:24 AM: Message edited by: mc5w ]
British rules require a redundant grounding conductor in all occupancies. Here is northeast Ohio the vast majority of our customers require it as a job specification.
If you have ever had to open up a wall and reconnect an EMT joint like I have you would not be asking this question and you would realize why the British require redundant grounding conductors in all occupancies and not just in hospitals.
[ May 07, 2005, 02:24 AM: Message edited by: mc5w ]
bphgravity
Senior Member
- Location
- Florida
Re: EMT as ground
Using a raceway or the sheath of a cable for the EGC requires good workmanship and proper fittings in order to be effective. I do like the idea of redundant bonding as it reduces total impedance and provides a fail safe.
Using a raceway or the sheath of a cable for the EGC requires good workmanship and proper fittings in order to be effective. I do like the idea of redundant bonding as it reduces total impedance and provides a fail safe.
pierre
Senior Member
- Location
- Westchester County, New York
Re: EMT as ground
I also am in favor of correct grounding, which sometimes includes redundant grounding, but do not use poor workmanship in any of the equations.
Poor workmanship is not restricted to the couplings/connectors of raceways, or the connection of sheathing for AC, it is also extended to loose connections of equipment grounding conductors, using the incorrect type of termination for equipment ground connections, etc...
So when discussing equipment grounding and EFFECTIVE GROUND FAULT CURRENT PATHS, we should talk about what works and what doesn't work effectively without the discussion of workmanship - that can be a whole other conversation - one that will go on forever.
I also am in favor of correct grounding, which sometimes includes redundant grounding, but do not use poor workmanship in any of the equations.
Poor workmanship is not restricted to the couplings/connectors of raceways, or the connection of sheathing for AC, it is also extended to loose connections of equipment grounding conductors, using the incorrect type of termination for equipment ground connections, etc...
So when discussing equipment grounding and EFFECTIVE GROUND FAULT CURRENT PATHS, we should talk about what works and what doesn't work effectively without the discussion of workmanship - that can be a whole other conversation - one that will go on forever.
james wuebker
Senior Member
- Location
- Iowa
Re: EMT as ground
I agree with dereckbc. Even if you have good workmanship putting the conduit together there's always someone that can hit it and break it apart at the coupling and you can't see it, which then you have no ground. I've seen this a lot in commerical buildings up in the ceiling. The place might have a forklift putting a box away and by accident they hit the conduit breaking it apart. Of course they didn't see themselves hitting it and now it may no have a ground unless you might have another run of conduit going to the same outlet. I don't like to re-lie on that so I do run a ground conductor with every circuit.
Bye now,
Jim
I agree with dereckbc. Even if you have good workmanship putting the conduit together there's always someone that can hit it and break it apart at the coupling and you can't see it, which then you have no ground. I've seen this a lot in commerical buildings up in the ceiling. The place might have a forklift putting a box away and by accident they hit the conduit breaking it apart. Of course they didn't see themselves hitting it and now it may no have a ground unless you might have another run of conduit going to the same outlet. I don't like to re-lie on that so I do run a ground conductor with every circuit.
Bye now,
Jim
allenwayne
Senior Member
Re: EMT as ground
I remember working in NYC with BX cable the armour was the ground and often did I find loose fittings that arced as I opened a 30 year old fixture
.Have found this senario on gas pipe retro fitted BX and the gas system was still active
I remember working in NYC with BX cable the armour was the ground and often did I find loose fittings that arced as I opened a 30 year old fixture
.Have found this senario on gas pipe retro fitted BX and the gas system was still active hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: EMT as ground
Allen why is there current on the BX?
There shouldn't be.
Allen why is there current on the BX?
There shouldn't be.
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