Need advice on grounding/sub panel

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Jerrymosier

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Location
Georgia
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Housing electrician
I am the electrician at the University of Georgia, and in my past experience we did things by code because it was always required, we knew it and did it. Sometimes we didn't know the exact code reference for each things so when I see issues, I have to go back and search to get the right section in NEC showing things are a direct violation. We have no inspections on campus, so various contractors know this and do whatever they want as well some internal electricians. I discover things constantly, hence the term if you look for water you'll find the ocean.

This brings me to yet another issue I discovered yesterday. All of our resident units whether it's a small unit or full on apartment/townhouse has an MDP then the units have individual panels inside them (main lug only). Those panels are what feeds each apartment/resident unit. I opened up one yesterday to check a circuit that was tripping and found the issue. I tried to upload the pic but it won't. The issue is it's a single phase panel fed with 2 1/0 A/B phase conductors and a 1/0 neutral and no ground. There is a grounding bushing and on there is a #6 wire (phased green....I know) and it's directly connected to the ground bar.

So this is a sub panel fed from an MDP with no EGC pulled into it. Can someone please direct to the proper section in NEC that will show that this is incorrect? I need to forward this up administration for correction if so. There could possibly be over 200 units that will need this done on so it's a major problem provided I can show the violation in code.

Thanks for any help
 
Jerrymosier said:
I am the electrician at the University of Georgia, and in my past experience we did things by code because it was always required, we knew it and did it. Sometimes we didn't know the exact code reference for each things so when I see issues, I have to go back and search to get the right section in NEC showing things are a direct violation. We have no inspections on campus, so various contractors know this and do whatever they want as well some internal electricians. I discover things constantly, hence the term if you look for water you'll find the ocean.

This brings me to yet another issue I discovered yesterday. All of our resident units whether it's a small unit or full on apartment/townhouse has an MDP then the units have individual panels inside them (main lug only). Those panels are what feeds each apartment/resident unit. I opened up one yesterday to check a circuit that was tripping and found the issue. I tried to upload the pic but it won't. The issue is it's a single phase panel fed with 2 1/0 A/B phase conductors and a 1/0 neutral and no ground. There is a grounding bushing and on there is a #6 wire (phased green....I know) and it's directly connected to the ground bar.

So this is a sub panel fed from an MDP with no EGC pulled into it. Can someone please direct to the proper section in NEC that will show that this is incorrect? I need to forward this up administration for correction if so. There could possibly be over 200 units that will need this done on so it's a major problem provided I can show the violation in code.

Thanks for any help
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What year/code cycle was these installations done? Could have been compliant at the time.

Is neutral bonded to the case of each sub panel?
 
I would say maybe 10-15 years ago. Yes it's fed with EMT. I wasn't aware that could serve as an EGC at any point
 
infinity said:
Yes EMT is an EGC so there is no "major problem" with the installation. Look at 250.118.
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It was always my understanding that on sub panels and feeds that you had to have an EGC pulled back to the distribution panel. We’ve had instances where the chase way was used as a ground 20A or less, all others we had to pull the ground.
 
  • The circuit conductors contained in the conduit must be protected by an overcurrent device rated at 20 amperes or less.
 
Jerrymosier said:
I would say maybe 10-15 years ago.
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You need to determine which edition of the NEC applied during the construction, when looking at potential violations. It is not uncommon for a locale to be several editions behind the most current NEC.
 
Jerrymosier said:
It was always my understanding that on sub panels and feeds that you had to have an EGC pulled back to the distribution panel. We’ve had instances where the chase way was used as a ground 20A or less, all others we had to pull the ground.
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What is a chase way? All branch circuits and feeders require an EGC. A metal raceway listed in 250.118 can be used as the EGC.
 
infinity said:
What is a chase way? All branch circuits and feeders require an EGC. A metal raceway listed in 250.118 can be used as the EGC.
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For circuits above 20 amps or less right? This applies to 100 and 150 amp services fed from an MDP? And there’s no ‘inspections’ on campus so this was never properly looked at by anyone with knowledge of code
If what you guys say is correct, can you provide any code sections that state the metal raceway will work without an EGC in those panels? I’ve only known about 20 amps or less personally. I have always understood subpanels required an EGC all the way back to the panel.
If what you’re saying is correct, you have to assume all connectors and couplings must be tightened and can create a proper connection all the way back
 
Per the NEC, the metal raceway is almost always considered sufficient as the EGC for the conductors it contains. Exceptions are for certain types of flexible conduit.

There may be a local code or job requirement for a wire EGC. In a place like a University you probably have a bunch of job requirements that exceed the NEC, for example requiring 12 AWG wire as minimum size, mandating maximum voltage drop, etc. But these requirements go beyond what the NEC itself requires.

-Jon
 
Jerrymosier said:
I have always understood subpanels required an EGC all the way back to the panel
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Jerrymosier said:
Where do you think I got the post that I quoted a few posts up
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As i said before a feeder requires an EGC. 250.118 tells us that EMT qualifies as an EGC that's why I asked if you read that section. Normally I would post the section but I don't have access to my codebook at the moment.
 
Jerrymosier said:
For circuits above 20 amps or less right? This applies to 100 and 150 amp services fed from an MDP? And there’s no ‘inspections’ on campus so this was never properly looked at by anyone with knowledge of code
If what you guys say is correct, can you provide any code sections that state the metal raceway will work without an EGC in those panels? I’ve only known about 20 amps or less personally. I have always understood subpanels required an EGC all the way back to the panel.
If what you’re saying is correct, you have to assume all connectors and couplings must be tightened and can create a proper connection all the way back
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Unless there are requirements by the engineer for the building or a local rule, there is nothing in the NEC about circuits above 20A. All circuits, including feeders and services, can have a metal raceway as the EGC.
 
Little Bill said:
Unless there are requirements by the engineer for the building or a local rule, there is nothing in the NEC about circuits above 20A. All circuits, including feeders and services, can have a metal raceway as the EGC.
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Ok thank you. I wanted to be 100% sure before I take this further. That’s all I was asking because we always knew the rule of 20A or less. We used to never NOT pull a separate EGC. It was too much to put our reputation on the line that all connections were tight versus the tiny cost of just adding an extra wire in a conduit. In fact, I have never understood why people wish to save a couple dollars in cases like this instead of just adding one more wire. Code compliant or not, just doesn’t make sense
 
Jerrymosier said:
Ok thank you. I wanted to be 100% sure before I take this further. That’s all I was asking because we always knew the rule of 20A or less. We used to never NOT pull a separate EGC. It was too much to put our reputation on the line that all connections were tight versus the tiny cost of just adding an extra wire in a conduit. In fact, I have never understood why people wish to save a couple dollars in cases like this instead of just adding one more wire. Code compliant or not, just doesn’t make sense
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It's a design issue not a code issue. The NEC is a minimum standard. Some designers and installers always pull a wire type EGC in EMT even though it's not required. Regarding the 20 amp limitations of some metal raceways you're correct they do exist in 250.118. EMT is just not one of them.
 
infinity said:
It's a design issue not a code issue. The NEC is a minimum standard. Some designers and installers always pull a wire type EGC in EMT even though it's not required. Regarding the 20 amp limitations of some metal raceways you're correct they do exist in 250.118. EMT is just not one of them.
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So it would have to be rigid for this to be a proper application without pulling an actual wire?
 
Jerrymosier said:
It was always my understanding that on sub panels and feeds that you had to have an EGC pulled back to the distribution panel. We’ve had instances where the chase way was used as a ground 20A or less, all others we had to pull the ground.
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The code does not say that and never has said that. The EMT is the only equipment grounding conductor that is required for that feeder.
 
Jerrymosier said:
So it would have to be rigid for this to be a proper application without pulling an actual wire?
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No, it does not have to be rigid. See 250.118(4). All 14 list items in that section are permitted to be used as equipment grounding conductors. If there are any limits or restrictions on that use they are shown after the list item. List item (4) for EMT has no such restrictions.
 
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