Line side taps and disconnect

[ggunn]

1 Am I misunderstanding you? What about the PV EGC?
How is it a supply side connection if the PV EGC is connected to the same grounding bar as the loads?

Whether a PV interconnection is load side or line (supply) side has nothing to do with grounding.

My morning apple break is over, so I have to go back to work.

 

[PVfarmer]

I am agnostic on the issue; the AHJ makes the call and I comply, whichever way it goes, and it goes both ways.

Whether a PV interconnection is load side or line (supply) side has nothing to do with grounding.

And then what happens when the AHJ tells you that you must do something which POCO doesn't like?
Only one of them lets you turn the thing on, because it is connected to their grid, through their meter and conductors.

And since you aren't an AHJ, why should I go by your opinion?

 

[SolarPro]

The power company is an AHJ. Not sure who would trump their requirements. Build it the way the AHJ wants it and move on to the next project. In a perfect world, every AHJ would have the same set of requirements. But we don't live in a perfect world. So get used to tracking requirements from one jurisdiction to the next.

As they say: "There are always three opinions about how to apply the Code. There's your opinion, my opinion and the AHJ's opinion. The only opinion that matters is the AHJ's."

 

[jaggedben]

1 Am I misunderstanding you? What about the PV EGC?
How is it a supply side connection if the PV EGC is connected to the same grounding bar as the loads?

How is it not? Supply-side is about the ungrounded conductors and the location of their disconnecting means. Neutrals and grounds don't have disconnecting means, so if it's all in the same enclosure then what's the difference? All grounded parts are ultimately connected to each other anyway.

I guess safety may be debatable, but having a supply side PV EGC connected to the MSP ground bar changes function as far as I can tell.

It doesn't really change the function, which is still to provide an effective ground fault current path. Yes the rules for things with different names are slightly different, but 250.122 and 250.66 produce the same result most of the time and only one wire size off at most, so far as I've noticed. And since you now can't have the PV disconnect more than 10ft from the splice, the concerns of voltage drop or whatever are not likely to make a real world difference.

 

[jaggedben]

And then what happens when the AHJ tells you that you must do something which POCO doesn't like?

Solving those problems is why they pay you the big bucks.

 

[ggunn]

And since you aren't an AHJ, why should I go by your opinion?

Which opinion is that, exactly? The only opinion I have expressed on this issue is that you should do what the AHJ governing the job tells you to do because their opinions differ. Otherwise I do not have an opinion.

 

[shortcircuit2]

If you line side tap the SEC either at the meter ( which is not allowed here)
Or on the line side of the first means of disconnect. Would the the disconnect that the taps feed be required to have a GES. Cold water and ground rod.?Single family dwelling.
The disconnect feeds the PV system.

I believe this is now a service disconnect
Thanks

I AGREE with you. It's a SERVICE DISCONNECT. Now just have to get CMP-4 to open their eyes to the reality.

 

[Smart $]

I AGREE with you. It's a SERVICE DISCONNECT. Now just have to get CMP-4 to open their eyes to the reality.

With a supply-side connection, is there any [significant] energy transfer from the utility to the premises?

If the answer is no, then the premise of service is not met. The electrical utility must literally provide service to qualify as a service disconnecting means.

https://www.google.com/search?q=service

 

[jaggedben]

With a supply-side connection, is there any [significant] energy transfer from the utility to the premises?
...

Absolutely there is. I think perhaps you're not asking the question you intend to ask.

 

[GoldDigger]

With a supply-side connection, is there any [significant] energy transfer from the utility to the premises?

If the answer is no, then the premise of service is not met. The electrical utility must literally provide service to qualify as a service disconnecting means.

https://www.google.com/search?q=service

Absolutely there is. I think perhaps you're not asking the question you intend to ask.

...is there any [significant] energy transfer from the utility to the premises over that connection?

Is that what you are hinting at?

 

[electricalist]

So we need a transfer switch and then everybody would agree.


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[Smart $]

Is that what you are hinting at?

Correct, but it amounts to the same thing. No significant energy transfer [from the utility to the premises over this connection], no service provided by utility, not a service disconnecting means.

 

[Smart $]

Absolutely there is. I think perhaps you're not asking the question you intend to ask.

Afraid not... and I am asking the correct question. You are just reading more [or something completely different] into it.

Supply-side connection energy transfer: UTILITY<--PV SYSTEM (no service provided).

 

[GoldDigger]

Correct, but it amounts to the same thing. No significant energy transfer [from the utility to the premises over this connection], no service provided by utility, not a service disconnecting means.

And yet the upstream wires on the line side of the PV disconnect are unambiguously service conductors at some point as long as they provide power, through a second disconnect, to local loads, even though they also connect to the PV ouput.

Which leads to the philosophical (rather than literal NEC) question of whether something that disconnects from service conductors is necessarily a service disconnect, regardless of power flow.

If you have a PV farm with no significant local loads, then there is a viable argument that the POCO conductors are not service conductors in the first place.

 

[ggunn]

I AGREE with you. It's a SERVICE DISCONNECT. Now just have to get CMP-4 to open their eyes to the reality.

Opinion stated as fact. Saying it in ALL CAPS doesn't make it true.

 

[Smart $]

And yet the upstream wires on the line side of the PV disconnect are unambiguously service conductors at some point as long as they provide power, through a second disconnect, to local loads, even though they also connect to the PV ouput.

Which leads to the philosophical (rather than literal NEC) question of whether something that disconnects from service conductors is necessarily a service disconnect, regardless of power flow.

If you have a PV farm with no significant local loads, then there is a viable argument that the POCO conductors are not service conductors in the first place.

The argument is self-resolving through the converse of Cogito ergo sum, i.e. "I think, therefore I am."

Is it a service disconnect?
I think not {poof}

 

[jaggedben]

Afraid not... and I am asking the correct question. You are just reading more [or something completely different] into it.

Supply-side connection energy transfer: UTILITY<--PV SYSTEM (no service provided).

I maintain your original statement was vague, and the subsequent clarifications were necessary. And you know I disagree with your logic. But I'm not going to rehash why, when we've already been there in other threads. It's of little use to the OP, who needs to know his AHJ's opinion more than ours.

 

[shortcircuit2]

Opinion stated as fact. Saying it in ALL CAPS doesn't make it true.

Sorry for yelling...just frustrated this is still an issue. It has been a problem in my world for multiple Code cycles now.

 

[electricalist]

For what it's worth I appreciate everyone's input.
No disrespect towards anyone when I say interpretations + theory+preference can make these type of installs sometimes not worth getting involved in.

We put taps in the first panel. L1 L2 line side of the breaker. Neutral landed on neutral bar. Ground landed on same bar , feeding a 60 amp service rated disconnect with 50 amp fuses. Neutral and ground bonded in the disconnect feeding the PV equipment.

Will the pass? I'll know today or tomorrow when the 5 installs are inspected.
I'll will post the outcome when I find out. Unfortunately it won't change much about about the disagreements here but maybe it'll help others see how these set ups are viewed in different areas.
Thanks


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[shortcircuit2]

Smart $]With a supply-side connection, is there any [significant] energy transfer from the utility to the premises?

I can not find [significant] in our Code. The electronics in the inverter and production metering equipment use energy from the serving utility to operate. Without the energy transfer Utility>-- Premises Wiring System, the Grid Interconnected Electric Power Production Source will not operate.

If the answer is no, then the premise of service is not met. The electrical utility must literally provide service to qualify as a service disconnecting means.

The answer is yes...the premise of service is met. Without the service from the electric utility, the Grid Interconnected Electric Power Production Source will not operate.