emt used as equipment ground

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Sometimes I think specs go a little overboard on bonding myself, by requiring you to install an EGC.


If the EMT serves as an acceptacle EGC to begin with and you pull in an EGC (cause the specs indicate you have to), it makes for a lot of bonding jumpers,terminations and crowding in junction boxes, that you would'nt otherwise have.

JAP>
 
jap said:
Sometimes I think specs go a little overboard on bonding myself, by requiring you to install an EGC.

W
If the EMT serves as an acceptacle EGC to begin with and you pull in an EGC (cause the specs indicate you have to), it makes for a lot of bonding jumpers,terminations and crowding in junction boxes, that you would'nt otherwise have.

JAP>
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Amen!
 
This is what I think it should be- Emt exposed in outdoor wet locations or in corrosive locations, or where installed by less than stellar electricians such as myself, shall have an equipment grounding conductor installed .
 
macmikeman said:
This is what I think it should be- Emt exposed in outdoor wet locations or in corrosive locations, or where installed by less than stellar electricians such as myself, shall have an equipment grounding conductor installed .
Click to expand...


We better leave the rule like it is.

If a high maintenance inspector got crossways for some reason and suggested I install an EGC for being "Less than Stellar" I'd probably take it personally and beat the wadden out of him.....:)

JAP>
 
I have a table that appeared in older 1940's and 1950's NEC's that I still use, 1/2 EMT is good up to 100 Amps as a ECG conductor. I like "steel" connectors as opposed to "die cast" and for indoor work green wire is just a waste of copper. I think green was even allowed as a hot until '05 or so. Canada still allows 14 AWG up to 20 or 30 amps in NM-D up there. the changes to what's now 250.122 in the 50's were not well substantiated in my opinion.
 

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tortuga said:
I have a table that appeared in older 1940's and 1950's NEC's that I still use, 1/2 EMT is good up to 100 Amps as a ECG conductor. I like "steel" connectors as opposed to "die cast" and for indoor work green wire is just a waste of copper. I think green was even allowed as a hot until '05 or so. Canada still allows 14 AWG up to 20 or 30 amps in NM-D up there. the changes to what's now 250.122 in the 50's were not well substantiated in my opinion.
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The only place I see that table from way back as being useful would be for a feeder tap - but even then tap rules usually limit the length of the tap conductors.

Otherwise when else would you have 100 amp overcurrent protection on conductors that will fit in a 1/2 raceway? Some motor applications maybe you get close, but that is about it.
 
kwired said:
The only place I see that table from way back as being useful would be for a feeder tap - but even then tap rules usually limit the length of the tap conductors.

Otherwise when else would you have 100 amp overcurrent protection on conductors that will fit in a 1/2 raceway? Some motor applications maybe you get close, but that is about it.
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Agreed it is not a useful table, it is just an example that smaller sizes of EMT have been long been accepted as handling as much fault current as any size wire that can fit in it. Having a redundant grounding conductor is not a bad idea though. I have seen a plumber hammer on 1/2" EMT with a sledge hammer to "move it slightly out of his way".

In some situations going up one size of conduit to accommodate an ecg is a big difference in the amount of work. For example when I have 555 on the jobsite that only goes up to 2" EMT. If I have a 3 phase feeder I can run four 4/0 AL XHHW-2 in 2" EMT. If I add a #4 AL XHHW-2 ECG I now need to go up to 2-1/2" and get a different bender.
Knowing that 2" EMT is a more than adequate ECG for a 200A feeder is factor in that decision.
 
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