We have a 600 amp single phase service with a self contained meter base feeding (2) separate services in a office building and a storage building. Both services are 200 amp with main breakers. The office service conduit is installed under concrete slab and the storage conduit is outdoors. Both services do not exceed the 3' rule once entering the building. The AHJ requested that the services have a means of disconnect, which we then installed a 600 amp NF switch. Now that the inspection has occured he is requesting overcurrent protection in the disconnect. Is the overcurrent protection required in this case in the disconnect if we have main breakers in the services
service disconnecting means
- Thread starter boritz
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Why was a disconnect required in the first place. Were the disconnects not grouped??? IMO it does not sound like a disco is required at all but I am a bit unclear of the install. 2- 200 amp breakers but you have a 600 amp meter- what is a self contained meter- no CT's???
service disconnecting means
I'm still trying to figure out why the disconnect was needed. This was required by the AHJ, so we did it. The 600 amp disc. is located next to the meter base as requested, then the 2 services fed off of that. The local utility has a 600 amp self contained single phase meter base just like a 200 amp
I'm still trying to figure out why the disconnect was needed. This was required by the AHJ, so we did it. The 600 amp disc. is located next to the meter base as requested, then the 2 services fed off of that. The local utility has a 600 amp self contained single phase meter base just like a 200 amp
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Without the 600 amp disconnect the 200 amp service disconnects are not grouped. So the question remains does the 600 amp disco require an OCPD?
Yes, that is correct. The plans where approved with a disconnect, but the disconnect was not shown fused or non fused. His response was I assumed you were fusing it. My question then becomes to him, if we missed showing fused or NF, then you should have rejected the plans and requested what you needed
service disconnecting means
Rob,
Look at 230.90 exception #3. Would this apply to our situation
Rob,
Look at 230.90 exception #3. Would this apply to our situation
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
230.90 does not apply here, as with the addition of the 600 amp disconnect, your service conductors are now feeders. But the 600 amp disconnect is wrong as it does not have over current protection and the now feeders are not protected at thier ampacity. I think the way to solve this is to use, say, a 600 amp I-Line panel with 2 200 amp breakers as service disconnects (this would meet 230.90)
we have done separate services like this at other locations in the past, where we have a meter base, then fed separate main breaker panels as long as we didn't exceed the 3' rule once we entered the building. We never had to install a disconnect in the past and always got an approved inspection. If the NF disconnect is only breaking the ungrounded conductors is this code approved?
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
If I understand your description correctly, the ones you did in the past are wrong. The 600 amp non fuse disco is not compliant either. Making the disco fusible won't help as you have to protect what are now feeders going to the 200 amp panels. This also raises GES issues and EGC to the 200 amp panels as they now would be sub panels.. I think the only solution is to redesign the service in a compliant manner, one possibility is as I described in my previous post.
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- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Why would they be feeders if the disconnect is NF. I think they are still service conductors till they reach the first OCPD.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
My feeling as well.
This is how I see it and I'm sorry to say that the 600 amp, NF switch accomplishes nothing. The service disconnects would still be at the 200 amp OCPD in the panel, therefore the service disconnects are still not grouped. If you use a 600 amp fused disconnect then it would become the service disconnect and for your conductors to the 200 amp panels the tap rules would apply. The conductors on the exterior of the building can be taps of unlimited length. The ones that run into the building would need to comply with the 10' or 25' tap rule or if the conduit is completely encased in 2" of concrete then those conductors are considered outside of the building and can also be of unlimited length.
well after all this, the inspector just called and said the inspection is now OK after he came back and reviewed it a little closer. As originally designed, the disconnect was only supposed to be a means of disconnect to the site where there are 2 separate services approx. 200' apart. I guess after all this arguing with the inspector, I can now go have a beer...thanks for your help
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
230.70 states that means shall be provided to disconnect all conductors in a building or other structure from the service entrance conductors. IMO, a NF disconnect attains that.
Also I am not sure the disconnects are not grouped-- I am still unclear of the setup.
Also I am not sure the disconnects are not grouped-- I am still unclear of the setup.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
You're welcome- glad it worked out
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
I think what you and others have said makes a good argument, but I based all my arguments on the fact that the service disconnects have to be grouped. Well, all ends well, as the OP is happy as he got his inspection, but I'm not convinced it is compliant.
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