Point of Connection, Commentary Note

[david]

690.64 Point of Connection.
Commentary Note
The supply-side connection is similar to installing a second service entrance, and the numerous requirements of Article 230 apply.

There is a 200 amp panel mounted on the outside of the dwelling next to the utility meter, with a 200 amp main. One 30 amp 2-pole and one 100 amp 2- pole.

The 200 amp breaker is feed from taps to service entrance conductors on the load side of the utility meter.

30 amp 2 pole from the PV system from the array mounted on the house back feeds the bus(200 amp exterior panel)

There is a 100 amp panel at the garage back feed by a 30 amp 2-pole breaker from the PV array at the garage.
. A 100 amp 2 pole Main at the garage panel back feeds the 100 amp 2-pole in the panel on the exterior of the house.

Since the 200 amp exterior panel at the house was installed by the PV contractor he says this is not a service panel it?s a PV panel and none of the rules in 230 apply.

My question is should this 200 amp panel be considered a service disconnect and is it required to be grouped with the service disconnect in the basement of the house

 

[GoldDigger]

The NEC, at least from 2011 on, explicitly states that the PV disconnect is not a service disconnect, but leaves open just what rules it does or does not have to comply with anyway, including the hot topic of whether the disconnect gets a ground/neutral bond.
There are labelling and other rules specifically related to PV disconnects.

 

[david]

The reason I am posting this is the contractor says he has done 100 of systems this way and he is calling me every name in the book M and A and everything else
I want to give him the benefit of doubt because this is his field of expertise and I am a little green on this subject.
I cannot see the exterior panel any differently than a 200 amp service disconnect tapped to a 200 amp existing service with the service disconnects now located in to different locations one outside and one inside the dwelling.

The 100 amp breaker in the garage being a feeder from the 100 amp breaker from the exterior panel at the house.

The PV contractor said he did it this way to avoid the 120% requirement in article 290.
He believes because there is no load at the garage or the exterior house panel The only breakers currently in these panels is for the PV system that this is all PV equipment.
He is really mad and says I have no blankly blank reason to look anywhere other than article 690

 

[david]

The NEC, at least from 2011 on, explicitly states that the PV disconnect is not a service disconnect, but leaves open just what rules it does or does not have to comply with anyway, including the hot topic of whether the disconnect gets a ground/neutral bond.
There are labelling and other rules specifically related to PV disconnects.

Then I am confused by the 200 ample panel and the 100 amp feeder between it and the garage.

He is Working out of the 2011 NEC the state is code is the 2008 NEC

 

[ggunn]

The reason I am posting this is the contractor says he has done 100 of systems this way and he is calling me every name in the book M and A and everything else
I want to give him the benefit of doubt because this is his field of expertise and I am a little green on this subject.
I cannot see the exterior panel any differently than a 200 amp service disconnect tapped to a 200 amp existing service with the service disconnects now located in to different locations one outside and one inside the dwelling.

The 100 amp breaker in the garage being a feeder from the 100 amp breaker from the exterior panel at the house.

The PV contractor said he did it this way to avoid the 120% requirement in article 290.
He believes because there is no load at the garage or the exterior house panel The only breakers currently in these panels is for the PV system that this is all PV equipment.
He is really mad and says I have no blankly blank reason to look anywhere other than article 690

What are your respective roles in this project? Do you work for him or does he work for you? If he works for you (and if your characterization of him is accurate, of course) I would fire him on the basis of attitude alone. Namecalling and derisiveness have no place on the job.

 

[david]

What are your respective roles in this project? Do you work for him or does he work for you? If he works for you (and if your characterization of him is accurate, of course) I would fire him on the basis of attitude alone. Namecalling and derisiveness have no place on the job.

I am the electrical inspector and I have to certify the system before the utility will allow it to come on line

 

[david]

If I open the 30 amp breaker in the garage the PV array at the garage stops it s out-put, However it still has 100 amp supply energized from the 200 amp exterior panel at the house. So how am I not correct in defining this 200 amp exterior panel service equipment?

 

[GoldDigger]

With a line side tap, the PV disconnect is the one connected to the service wires. The 100A panel is a combiner and does not count as anything special.
Prior to 2014 the ampacity calculations are all based on the first breaker after the inverter, which would be the 30A in the sub.
He could just as easily, IMHO, have put a 30A breaker in the new 200A panel and avoided the sub completely. But he may have wanted it there to serve as a local disconnect for the inverter.
As for grouping, I cannot speak to the [2008] rules on that.
You are in that weird twilight zone where the PV disconnect is not quite a service disconnect, even though it has a connection to the service wires.
If he had two inverters and two 20A breakers, it would be clearer that the 100A panel is not the PV disconnect location.
I agree with his assertion that if there are no loads on the 200A panel it is the PV disconnect.
Did he put labels in both panels identifying them as PV and stating that no load circuits were allowed?

 

[jaggedben]

690.64 Point of Connection.
My question is should this 200 amp panel be considered a service disconnect and is it required to be grouped with the service disconnect in the basement of the house.

First of all, note that 230.71 only requires grouping for each set of service entrance conductors allowed in 230.40. Since the conductors to the PV disconnect (200A breaker) fit under 230.40(Exception 5), there's definitely a way to read that as saying that the PV disconnect does not need to be grouped with the other service disconnecting means. That is, as long as the normal service disconnecting means and the PV disconnecting means are each grouped, respectively.

As for whether the PV disconnect (200A breaker) should be officially considered a service disconnecting means, my opinion is that it is entirely up to you, as experts in the field disagree on interpreting the code. Mike Holt think's it's not a service disconnect, although he states it's a good idea to follow 230. Marvin Hamon (EE and writer for Solar Pro magazine) thinks 230 applies, although he acknowledges this is not explicit in the code. Just to cite a couple examples.

Just be consistent with applying whatever interpretation you decide to go with.

If nothing else, this would be an appropriate situation for enforcing 705.10 (although in most cases I think that section is rather onerous).

...
He is really mad and says I have no blankly blank reason to look anywhere other than article 690

Well, that's kind of silly, since if he knew his code he would be pointing to the sections of 230 that allow him to do what he's doing, or at least could be interpreted that way. Also, there's article 705 now so this isn't all in 690 anymore.

The NEC, at least from 2011 on, explicitly states that the PV disconnect is not a service disconnect...

I'm going to call you out and say that's false. :rant: Please cite chapter and verse. IMO there's plenty of sections with implicit connotations (in both directions) but nothing that is explicit.

 

[david]

Prior to 2014 the ampacity calculations are all based on the first breaker after the inverter, which would be the 30A in the sub.
He could just as easily, IMHO, have put a 30A breaker in the new 200A panel and avoided the sub completely. But he may have wanted it there to serve as a local disconnect for the inverter.

Since the feeder between the exterior panel is 100 amp and is supplied by a utility feed 200 amp panel and the gargage panel is also 100 amp with a 100 amp main it looks as though it is their to supply the garage with a 100 amp utility supplied feed.

 

[david]

I agree with his assertion that if there are no loads on the 200A panel it is the PV disconnect.
Did he put labels in both panels identifying them as PV and stating that no load circuits were allowed?

Why wouldn't the garage be considered a load?

I agree with his assertion that if there are no loads on the 200A panel it is the PV disconnect.
Did he put labels in both panels identifying them as PV and stating that no load circuits were allowed?

He put labels calling them PV but did not indicate no load circuits allowed

 

[david]

In both the garage and the basement of the house he has a GFCI receptacle with a switch on it (part of the Receptacle) that allows the PV system to supply the receptacle when the switch is thrown without putting out to any other load The PV system will not putout to other loads until the switch on the rec. is thrown again

I never saw one before he says they are new and allowed as part of the listed system

 

[david]

The PV array at the garage seems to be using a point of connection as describe in 690.64 (B) 2008 NEC

The PV array at the house seems to be using 690.64 (A) 2008 NEC, except the 200 amp panel is also supplying a 100 amp supply to the garage.

These are two different arrays and the work independent of each other.


The only direct connection point to the utility is at the house exterior panel.

If i remove the PV array from the garage i would still have 100 amp supply to the garage originating at the house exterior panel

 

[shortcircuit2]

My question is should this 200 amp panel be considered a service disconnect and is it required to be grouped with the service disconnect in the basement of the house

This has been debated here many times. I am of the opinion that it should be considered an additional disconnect and be grouped and subject to all the other requirement of 230 related to services.

First responders will be better off with the disconnects grouped for easy shutdown of power to the property.

shortcircuit

 

[david]

Well that is also how I would have considered it, but when I have seasoned electrician becoming irate, I tend to give much consideration to his /her opinion not because of the swearing and caring on but because of the experienced. My father when he was around always said act do what you believe is right do not re-act

I have much more reading to do. And I have found little help from the NEC commentaries on this subject.

 

[jaggedben]

...
If i remove the PV array from the garage i would still have 100 amp supply to the garage originating at the house exterior panel

I should say at this point that I'm not sure I'm totally following your description of the system. However, I don't see any reason for the 100A panel to be part of the PV install at the garage, if the other inverter is at the house. That is to say, that inverter at the garage should be tied directly to the 200A panel with the other inverter, and those should be the only circuits connected to the set of service-entrance conductors that are for the PV.

If this is a surreptitious attempt to add power to the garage under the solar permit, I think you are perfectly within bounds to object to it. (Was there an approved planset for this installation?)

 

[jaggedben]

In both the garage and the basement of the house he has a GFCI receptacle with a switch on it (part of the Receptacle) that allows the PV system to supply the receptacle when the switch is thrown without putting out to any other load The PV system will not putout to other loads until the switch on the rec. is thrown again

I never saw one before he says they are new and allowed as part of the listed system

Sounds like SMA's new Secure-Power-Supply. And yes, they are pretty new, less than a year old.

This shouldn't be considered a load for the purposes of the rest of the discussion.

 

[GoldDigger]

Sounds like SMA's new Secure-Power-Supply. And yes, they are pretty new, less than a year old.

This shouldn't be considered a load for the purposes of the rest of the discussion.

Right, and the SPS is structured such that the SPS outlet (not necessarily a receptacle, although they illustrate that case) will never be connected to either POCO or the main house wiring. This avoids the need for a large transfer switch. All that is needed is a disconnect on the inverter output to grid connection and on the SPS outlet.

 

[david]

I should say at this point that I'm not sure I'm totally following your description of the system. However, I don't see any reason for the 100A panel to be part of the PV install at the garage, if the other inverter is at the house. That is to say, that inverter at the garage should be tied directly to the 200A panel with the other inverter, and those should be the only circuits connected to the set of service-entrance conductors that are for the PV.

If this is a surreptitious attempt to add power to the garage under the solar permit, I think you are perfectly within bounds to object to it. (Was there an approved planset for this installation?)

For residential there is no electrical permit (Building Permit) required. The electrical inspection is triggered by the utility company(s) requirements any time wind, solar, battery, or any other system that brings power or potentially could bring power onto their grid must be certified by an electrical inspector

 

[david]

If this is a surreptitious attempt to add power to the garage under the solar permit, I think you are perfectly within bounds to object to it. (Was there an approved planset for this installation?)

The garage has no other power the 100 feeder from the 200 amp exterior house panel to the garage brings the normal utility power to the garage but is serving the duel purpose of greating a tie to the 200 amp exterior ?PV panel? at the house using the 100 amp feeder between the house and the garage.

The PV system is DC. Everything being discussed is new and installed by the PV contractor. The PV system in the basement of the house, the new 200 amp exterior panel, the new 100 amp feed between the panels (exterior house and garage) the 30 amp breaker, at the exterior house panel, The new 100 amp panel in the garage, the 30 amp breaker in that panel for the garage array connection point, the new PV system in the garage.

The PV system in both the house and the garage have a watt hour meter, utility Interactive System,

I do not inspect many DC PV systems most of the PV systems around here only bring AC into the building from the array. This contractor has taken pride in saying he is not afraid of the DC systems and any monkey after taking a two hour course could install AC systems.

This contractor only uses PVC conduit for his systems and claims using metal conduit will create a ?shocking hazard? in the DC systems. He claims there are code changes in 2011 and 2014 that allow the DC without metal conduit into the garage and the house. Well at least he claims there are code changes that make his installation totally compliant with the code.

I questioned him about the grounding for his DC array and he claims because it is an ungrounded DC System only the equipment grounding is required at the array and no grounding electrode system is required at the array since he is using the AC grounding electrode system at both the exterior 200 amp panel at the house, for the house array and the interior 100 amp panel at the garage for the garage array.

I not buying the PVC explanation for the DC entering the buildings I cannot see how the metal conduit would cause a hazard if properly grounded.

I need to do more research on the 2011 and 2014 NEC changes I do not have to except those changes since we are under the 2008 NEC but I am willing to.