Utility CT metering of solar?

tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Question for you utility folks, and possibly solar folks,
Is there anything special to net metering commercial solar? Are the actual CT's different size or type?
Are the meter jaws different? Anything ?
I was asked look into this for a church.
They have a proposed roof top solar project lined up 30kVA, and there is a July deadline now.
they have what appears to be an existing service of 400-500A at 208V 3ph,
pole bank of three cans then service is underground from pole.
Switch gear in in church basement has 5 main breakers and a CT metering section below, probably 1970's era.
This particular utility is very large possibly thru mergers and buy outs and has massive territory in several states they appear to have a unified standard for CT metering, that this churches CT meter setup does not meet, but it did meet at one time.

There was no issue with the Church and the utility prior to the request for solar net metering, and since the Church's demand usage is very low the utility does not need to upgrade a transformer or do anything other than install a NET meter.
The utility wants the CT's brought up to current standard, which involves moving the location of the Meter, and since the CT's have to be close to the meter (like within a foot) its no small task and the cost will kill the project.
I have ran into this beofre when CT's were on a pole and the utility did not want metering on their pole, but I am curious if there is a technical or life safety reason to upgrade the CT's or is this just red tape?
thanks
 
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There is always a chance in any solar project that an AJH will require that something else be brought up to the current codes or standards. That's what the utility is doing here. You can try to talk them out of it but if they require it for the solar install then you have to give it to them. Utility standards change over time and they will take the opportunity to get a customer to update to the current standard.
 
pv_n00b said:
There is always a chance in any solar project that an AJH will require that something else be brought up to the current codes or standards.
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AKA "you touch it, you fix it". Here in Austin there are a lot of residences and some commercial buildings that were constructed before an external service disconnect was required by the city code; adding a PV system will trigger a requirement to upgrade the service to present code even when the solar is to be added on the load side of the service OCPD.
 
Thanks for the replies!
The issue at hand here is the Oreogn rules, the 'meter' while located outdoors is basically in a little courtyard with no exterior accesses and there is a requirement for a PV disconnect switch that must be 'readily accessible' to the public utility 'at all times' and located within 10 feet of the public utility’s meter.
They want the PV disconnect on the front of the building, so they are requiring the 'meter' to move, but their 'meter' cant be more than a few feet from the CT can that effective means the service has to move.
I was able to get a a reference to the Oregon Administrative Rule (OAR) 860-039-0015:
(2) Except for customer-generators established as net metering customers prior to the effective date of this rule, a customer-generator of a public utility must install and maintain a manual disconnect switch that will disconnect the net metering facility from the public utility’s system. The disconnect switch must be a lockable, load-break switch that plainly indicates whether it is in the open or closed position. The disconnect switch must be readily accessible to the public utility at all times and located within 10 feet of the public utility’s meter.
Then there is a section (b)
(b) The disconnect switch may be located more than 10 feet from the public utility meter if permanent instructions are posted at the meter indicating the precise location of the disconnect switch. The public utility must approve the location of the disconnect switch prior to the installation of the net metering facility.
So perhaps I'll try for that wish me luck!
 
Why do you put "meter" in quotes? If the POCO's metering equipment is not up to present code the AHJ might require you to bring it up irrespective of the location of the PV AC disconnect.
 
ggunn said:
Why do you put "meter" in quotes?
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Thanks yeah i put that in quotes because the POCO had approved the net-metering with the condition of moving the 'meter' so its within 10 feet of the PV AC disconnect, and the chosen location was about 50 feet away from the CT can, so Church was given the impression that moving the 'meter' meant just move the little meterbase not the entire CT cabinet which is part of the switchgear, and thus move the service. I spotted this discrepancy on the plans as I know the utility requires the meter to be within a few feet of the CT can.
 
tortuga said:
Thanks yeah i put that in quotes because the POCO had approved the net-metering with the condition of moving the 'meter' so its within 10 feet of the PV AC disconnect, and the chosen location was about 50 feet away from the CT can, so Church was given the impression that moving the 'meter' meant just move the little meterbase not the entire CT cabinet which is part of the switchgear, and thus move the service. I spotted this discrepancy on the plans as I know the utility requires the meter to be within a few feet of the CT can.
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Yes, a POCO meter must include its CT enclosure.
 
jaggedben said:
Why? That's not in the rule you quoted.
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The meter is in a courtyard thats surrounded by the building, there is no exterior access to the courtyard, there might have been at one time but they probably landlocked it 40 years ago with an addition. So if the PV disconnect were to be within 10' of the meter it would also be in this courtyard with no exterior accesses, putting it on the exterior perimiter of the building would ensure it can be accessed 'at all times'.
 
tortuga said:
The meter is in a courtyard thats surrounded by the building, there is no exterior access to the courtyard, there might have been at one time but they probably landlocked it 40 years ago with an addition. So if the PV disconnect were to be within 10' of the meter it would also be in this courtyard with no exterior accesses, putting it on the exterior perimiter of the building would ensure it can be accessed 'at all times'.
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The POCO may want you to move their meter outside the courtyard as well, which would make the PV disco easy to place.
 
In commercial applications the PV disconnect is often located away from the service disconnect. The service equipment might be in an electrical room inside the building and the PV disconnect outside of the building. Many utilities have similar language to that you quoted specifically for this. The utility can allow the PV disconnect to be in a different location than the service entrance disconnect and meter. They are not required to allow it but every one I have worked with that has this language does allow it. So go for it and ask.
 
ggunn said:
The POCO may want you to move their meter outside the courtyard as well, which would make the PV disco easy to place.
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Well yes the cost of that would kill the project, I was informed that the governor and state legislature here have a very pro PV stance, and had passed legislation to cut red tape for PV. I confirmed with the attorney indeed their is a state statute that basically says an electric utility may not require those kinds of upgrades for net-metering up to 2mw, unless its a specific safety issue, there was some technical compatibility issue or the service is being replaced.
I do need to get more into the particulars of this gets how safety issues are determined / decided, I'd imagine a real issue would be required to be dealt with either way, PV or not.
Hopefully I can help get this nice Church get some PV.
Thank you all for you input
 
tortuga said:
Well yes the cost of that would kill the project, I was informed that the governor and state legislature here have a very pro PV stance, and had passed legislation to cut red tape for PV. I confirmed with the attorney there is a indeed a state statute that basically says an electric utility may not require those kinds of upgrades for net-metering up to 2mw, unless its a specific safety issue, there was some technical compatibility issue or the service is being replaced.
I do need to get more into the particulars of how this gets determined / decided and can hopefully I can help get this Church some PV.
Thank you all for you input
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It may have nothing to do with PV per se. Austin city code now requires an external readily accessible service disconnect, although such was not always the case and there are many older services in place which are now non-compliant. When applications for PV are submitted for systems with these now non-compliant services, Austin Energy typically requires that the services be brought up to current code, i.e., you touch it, you fix it even for load side connected PV systems that do not involve the service conductors.
 
ggunn said:
It may have nothing to do with PV per se. Austin city code now requires an external readily accessible service disconnect, although such was not always the case and there are many older services in place which are now non-compliant. When applications for PV are submitted for systems with these now non-compliant services, Austin Energy typically requires that the services be brought up to current code, i.e., you touch it, you fix it even for load side connected PV systems that do not involve the service conductors.
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Interesting even for commercial?
That kind of ordnance appears to be exactly the red tape the state is cutting here, there may even be towns with ordinances like that on the books here that find their local ordnance no longer to be enforceable.
The 'state of Oregon' and 'cutting red tape' are probably not often combined in the same sentence, so best to take full advantage when it is. I'll update the thread when I learn more.
 
tortuga said:
Interesting even for commercial?
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Yes. I know of a PV system that was installed before the permit was secured that ran afoul of this. It was a pretty small system (~80kW) on the roof of an eight story building with a 2500A service, and the external service disconnect was going to be hideously expensive. I don't know how it turned out, but lessons were learned. I don't know how much the tuition was for this course in the School Of Experience.
 
It used to be really common for contractors to install residential and small commercial PV systems before the utility approval came through. From what I have heard there are a non zero number of installed PV systems that were either never given PTO or took years to get it due to problems the utility flagged during the review that were too expensive to fix. Utilities are a lot less open to asking forgiveness and not permission than building departments.
 
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