Utility disconnect not service disconnect

[hhsting]

I have project new building gas station convience store in which utility transformer secondary conductors enter non fuse Disconnect #1 outside convience store building then go to new utility meter/Ct then inside nearest entrance drop to 1000A 208V three phase panelboard. The 1000A panelboard has the grounding electrode system, main bonding jumper.

The engineer when told to move the GEC, main bonding jumper and to provide fuse in Disconnect #1 says Disconnect #1 is required by the local electric utility and is on line side of utility meter contractor to install but utility will own and maintain it and so by NEC 2014 Article 230 is not a service disconnect. No need to move GES and main bonding jumper.

Is the engineer correct? Disconnect #1 would not be serivce disconnect? Has anyone ever heard of such a thing utility disconnect owned and maintain non fuse line side is not considered service disconnect?

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[GoldDigger]

If there is no OCPD in it or adjacent to it, it cannot be a service disconnect.

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[ptonsparky]

Pretty common here, although on a smaller scale, dependent on the local POCO.

 

[hhsting]

So their should not be Grounding electrode system and main bonding jumper at the Disconnect #1?

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[ptonsparky]

So their should not be Grounding electrode system and main bonding jumper at the Disconnect #1?

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Equipment ahead of the Service Disconnect may be bonded to the grounded conductor. We often have rods there. Again smaller scale then yours.

I believe the engineer is correct.

 

[hhsting]

Yes but first disconnect service conductors hit and if its non fused then it would be violation of Article 230. However, the first disconnect service conductor hit according to engineer is utility disconnect required by the utility. I am inspecting the job and said to install fuse, grounding electrode system and main bonding jumper its violation of NEC 230 but I was told it is not service disconnect. Delimma is can you have first disconnect hit by service conductors non fuse disconnect without grounding electrode system and main bonding jumper and load side of that disco is it feeder or service conductors?

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[Cow]

I don't see the problem?

Install the nonfused "utility" disconnect. Bond the enclosure to the grounded conductor just like you would any piece of equipment upstream from a service disconnect. Done.

 

[electrofelon]

It sounds like a meter disconnect to me. It is permitted on the line side of the service disconnect. Note it doesn't have to be on the utility side of the service point, NEC still allows it to be a meter disconnect. Show the engineer 230.82.

Edit:. Check your available fault current, a NF disco is only rated 10k

 

[infinity]

I don't see the problem?

Install the nonfused "utility" disconnect. Bond the enclosure to the grounded conductor just like you would any piece of equipment upstream from a service disconnect. Done.

I agree, for the MBJ and GEC connections just pretend the meter disconnect does not exist and wire as you would any other service.

230.82 Equipment Connected to the Supply Side of Service Disconnect. Only the following equipment shall be
permitted to be connected to the supply side of the service disconnecting means:
(3) Meter disconnect switches nominally rated not in excess of 1000 V that have a short-circuit current rating
equal to or greater than the available short-circuit current, provided that all metal housings and service en-
closures are grounded in accordance with Part VII and bonded in accordance with Part V of Article 250. A
meter disconnect switch shall be capable of interrupting the load served. A meter disconnect shall be legibly
field marked on its exterior in a manner suitable for the environment as follows:

METER DISCONNECT
NOT SERVICE EQUIPMENT

 

[tom baker]

Question: What is the maximum available fault current? The non fused disconnects I have installed have a maximum fault current rating of 10,000 amps.
Our POCO requires a disconnect ahead of the meter for 480 volt services , but not CTs. I have done several, and was able to use a non fused disconnect. This disconnect is for the POCO, and has their lock on it.

 

[LarryFine]

Our POCO requires a disconnect ahead of the meter for 480 volt services , but not CTs. I have done several, and was able to use a non fused disconnect. This disconnect is for the POCO, and has their lock on it.

And it is not the service main disconnect.

 

[kwired]

Question: What is the maximum available fault current? The non fused disconnects I have installed have a maximum fault current rating of 10,000 amps.
Our POCO requires a disconnect ahead of the meter for 480 volt services , but not CTs. I have done several, and was able to use a non fused disconnect. This disconnect is for the POCO, and has their lock on it.[

Somewhat common here on a 200A or smaller 480 volt service as well, aside from rural services. POCO's feel potential incident energy is too high to risk their technicians pulling/installing meters while hot on those services. Same services on rural system that only supply one customer - they don't require the disconnect, but SOP for their technicians is to pull primary fuses before they pull any such meter and to reinstall meter before energizing the primary again.

Those that have such disconnect - they lock the disconnect - don't want customer to have easy access to unmetered conductors. I think they often lock the disconnect handle as well so it can't be turned off - smart meters don't transmit data if they are not energized.

NEC requires owner/occupant access to their service disconnect/service overcurrent devices, if it is behind utility company lock it is not accessible to the owner/occupant. That is a part of why such disconnect is not considered the service disconnecting means.

Fault current at such equipment is probably often under 10kA anyway when it comes to questions about suitability of the non fused disconnect because of AIC rating. These are usually only on 200 amp and less self contained metering. The meter itself probably only has 10 kA withstand rating - though AFAIK it shouldn't have an interrupt rating. Available current just isn't normally that high on those small services unless they are supplied from a larger source that feeds more than just that one service.

 

[MyCleveland]

All the replies nailed down all of the major issues.
It is typical here also for 480 services ONLY where you are routing through a meter base.
NOT required for 208 or 480 where a CT is being installed.
Have you checked with the utility designer, I have had a few jobs where they designed in a disconnect because they where new and did not understand the rules.
Doubtful that fault current is under 10k for this size of a service.

 

[hhsting]

Yup verified it twice its Square D 1000A, 240V, 3P, NF, Nema 3R utility disconnect switch. It is ahead of Utility CT Cabinet and meter. The system is 208/120V three phase. Downstream service.disconnect is 65kAIC rated so utility disconnect has to be rated at least 65kAIC.

Code allows meter disconnect and AIC has to be greater than avaliable fault current. It does not say any system voltage. Even if I talk to utility designer which I dont know who he/she is they would say what does AHJ have control over utility disconnect.

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[MyCleveland]

Yup verified it twice its Square D 1000A, 240V, 3P, NF, Nema 3R utility disconnect switch. It is ahead of Utility CT Cabinet and meter. The system is 208/120V three phase. Downstream service.disconnect is 65kAIC rated so utility disconnect has to be rated at least 65kAIC.

Code allows meter disconnect and AIC has to be greater than avaliable fault current. It does not say any system voltage. Even if I talk to utility designer which I dont know who he/she is they would say what does AHJ have control over utility disconnect.

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The local utility here modified the standard and now allow fusible disc when the SCC is above 10k. The AHJ has review of everything you install. I don’t think the argument if it fails can be ‘The utility co required this’.

If pushed against the wall, at a minimum make sure the EE understands this and get them to put in writing...Install the 10k rated switch while it is exposed to Xamps of available SCC.

 

[electrofelon]

Yup verified it twice its Square D 1000A, 240V, 3P, NF, Nema 3R utility disconnect switch. It is ahead of Utility CT Cabinet and meter.

just to be clear, who is calling it a utility disconnect switch? Does the utility require one in their construction specifications? In my experience, kinda odd to have one for a CT service.

The system is 208/120V three phase. Downstream service.disconnect is 65kAIC rated so utility disconnect has to be rated at least 65kAIC.

Well maybe. The utility disconnect switch has to be rated for the available fault current, not necessarily equal to or greater than that of the service disconnect

Even if I talk to utility designer which I dont know who he/she is they would say what does AHJ have control over utility disconnect.

IF it is on the utility side of the service point, then yes the AHJ has no say over what they do and its not your problem if they can/want to under rate it. IF it is on the customer side of the service point, then it needs to meet the NEC even if it is a utility requirement. There is a difference between something being on the supply side of the service point and something being "for" or "required" by the utility.

 

[hhsting]

just to be clear, who is calling it a utility disconnect switch? Does the utility require one in their construction specifications? In my experience, kinda odd to have one for a CT service.



Well maybe. The utility disconnect switch has to be rated for the available fault current, not necessarily equal to or greater than that of the service disconnect



IF it is on the utility side of the service point, then yes the AHJ has no say over what they do and its not your problem if they can/want to under rate it. IF it is on the customer side of the service point, then it needs to meet the NEC even if it is a utility requirement. There is a difference between something being on the supply side of the service point and something being "for" or "required" by the utility.

The engineer is calling it utility disconnect and says utility is requiring it.

Not sure where the service point is utility transformer is new and so is everything else.

Service disconnect overcurrent has to be rated greater than or equal to avaliable fault current and so since utility disco which is outside and service disco which is inside back to back so not far fault current wont change that much.

Code section meter disconnect allows it.
Not following regarding 10kA arguement. Are all of you saying if fault current is greater than 10kA then their is no utility disconnect. What exactly happens if fault current is greater than 10kA and utility disconnect is provided greater than or equal to fault current without fuse?

 

[hhsting]

Where in NEC it says service point downstream is NEC and upstream it is utility?

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[electrofelon]

Not following regarding 10kA arguement. Are all of you saying if fault current is greater than 10kA then their is no utility disconnect. What exactly happens if fault current is greater than 10kA and utility disconnect is provided greater than or equal to fault current without fuse?

NF disconnects are only rated 10k. IF you have more than 10k, you need to used a fused disco. Nothing says the "meter disconnect" cant be fused.

 

[hhsting]

NF disconnects are only rated 10k. IF you have more than 10k, you need to used a fused disco. Nothing says the "meter disconnect" cant be fused.

I'll let the engineer know and to coordinate and have utility worst case fault current at the utility disconnect and to provide in writing. I will also have in writing service point. His arguement I suspect would be AHJ has no control of utility disconnect however if its downstream of service point then AHJ has control over it. Just cant find it in code section???