EMT for grounding

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trojans4

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Semi -retired master electrician. Fully retired math and physics teacher.
I do only residential and only wire with romex. A friend of mine is in the process of building a new house. His father, who was an industrial electrician, wired the house for him. He did the whole house in EMT. Looks very good and neat compared to running romex by the way. My question is this: do you have to run a separate ground wire as an EGC in the EMT? I know that the NEC says in 250.118 that EMT can be used as an EGC. Supposedly the inspector told him he had to run a ground wire in the EMT so he did. I know some localities require residential to be wired in conduit but not in the location or state we live in so I have no experience with this. So, does the NEC require a separate ground wire in EMT? If it does can someone give me a code reference because I couldn't find one.
 
The correct term is equipment grounding conductor. Ground wire is not defined, but we know what you mean.
Take a look at 250.118
 
Generally speaking all metal raceways are suitable for equipment grounding with some restrictions on flexible metal conduits. Additional requirements may come up with bonding around a concentric KO when over 250 volts to ground, but the raceway itself is still suitable for EGC purposes.
 
tom baker said:
The correct term is equipment grounding conductor. Ground wire is not defined, but we know what you mean.
Take a look at 250.118
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My original post noted 250.118. That is why I was asking if there was some other article that I was not aware of. Since the EMT was an equipment grounding conductor it was hard to describe the other without calling it a wire. :)

I am not sure about a state building code but if there is one I am not aware of anything that would differ from the NEC. Since EMT is not required for residential in my state I have never seen one wired completely with EMT.

Thanks everyone for your replies.
 
One small addition, as soon as a separate EGC is installed it supercedes the conduit EGC. I believe this also means that you would need to ground your switches and outlets with the new EGC and pigtail at each box with a termination to the box in addition to the device.
 
Not that I don't do perfect work everytime, but a loose fitting degrades the ground. Having a wire in there eliminates the chance of a loose fitting adding resistance to your grounding path.
 
rlundsrud said:
One small addition, as soon as a separate EGC is installed it supercedes the conduit EGC. I believe this also means that you would need to ground your switches and outlets with the new EGC and pigtail at each box with a termination to the box in addition to the device.
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I disagree - if you are saying you need to install a (wire) bonding jumper between a metal box and a device simply because a (wire) EGC was pulled in the raceway. Metal to metal contact or a yoke designed to ensure bonding is still acceptable here. Patient care areas maybe are the exception.
 
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