705.12 (D) re- visited

[wwhitney]

I am interpreting the term service equipment in the definition given to be the PV source service equipment

I don't know Articles 690 or 705, but the Article 100 definitions say services always come from the utility, so unless there is some weird redefinition of the term service in Articles 690 or 705, there is no such thing as PV source service equipment.

See the Article 100 definitions of Service Equipment (which you already quoted), Service Conductors, and Service Point. Only a utility can provide a service point, and without a service point there are no service conductors and no service equipment.

Cheers, Wayne

 

[david]

I don't know Articles 690 or 705, but the Article 100 definitions say services always come from the utility, so unless there is some weird redefinition of the term service in Articles 690 or 705, there is no such thing as PV source service equipment.

See the Article 100 definitions of Service Equipment (which you already quoted), Service Conductors, and Service Point. Only a utility can provide a service point, and without a service point there are no service conductors and no service equipment.

Cheers, Wayne

I agree 100 % that the term service means utility service.

"Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served."

690.2
Inverter Output Circuit. Conductors between the inverter and an ac panelboard for stand-alone systems or the conductors between the inverter and the service equipment or another electric power production source, such as a utility, for electrical production and distribution network.

Service Equipment. The necessary equipment, usually consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the load end of service conductors to a building or other structure, or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.



And I am embarrassed to admit I was reading this as a permissive rule that a building was permitted to be supplied by a Parallel power production system

It’s not a permissive rule to supply a building with a parallel power production source. It’s a permissive rule for an additional utility service for the purpose of supplying a parallel power production system

230.2 Number of Services.
A building or other structure served shall be supplied by only one service unless permitted in 230.2(A) through (D). For the purpose of 230.40, Exception No. 2 only, underground sets of conductors, 1/0 AWG and larger, running to the same location and connected together at their supply end but not connected together at their load end shall be considered to be supplying one service.
(A) Special Conditions. Additional services shall be permitted to supply the following:
(5) Parallel power production systems

 

[ggunn]

I don't know Articles 690 or 705, but the Article 100 definitions say services always come from the utility, so unless there is some weird redefinition of the term service in Articles 690 or 705, there is no such thing as PV source service equipment.

See the Article 100 definitions of Service Equipment (which you already quoted), Service Conductors, and Service Point. Only a utility can provide a service point, and without a service point there are no service conductors and no service equipment.

Cheers, Wayne

There is disagreement among AHJ's as to whether or not a line side PV interconnection is a service entrance. San Antonio says it is, Austin says it isn't. We have to use different grounding strategies in the two jurisdictions.

 

[jaggedben]

I’m not making up my own definitions I’m interpreting the definition given.

You seem to be interpreting the term service equipment in the definitions given to be the utility service equipment

I am interpreting the term service equipment in the definition given to be the PV source service equipment

...

To me that is not within the bounds of 'interpretation'. In my opinion that is just radically ignoring the plain language of the code definitions and requirements, and making up your own definition. It is also ignoring the overwhelming industry consensus on how to interpret the code, and the electrical theory behind all of it. A PV system is not a service. A service is a connection to a utility.

Besides the code sections that have already been mentioned and quoted, you might look at 690.14 (A) (2011 NEC reference), which states that the PV disconnecting means is not required to be suitable for use as service equipment.

 

[ggunn]

To me that is not within the bounds of 'interpretation'. In my opinion that is just radically ignoring the plain language of the code definitions and requirements, and making up your own definition. It is also ignoring the overwhelming industry consensus on how to interpret the code, and the electrical theory behind all of it. A PV system is not a service. A service is a connection to a utility.

Besides the code sections that have already been mentioned and quoted, you might look at 690.14 (A) (2011 NEC reference), which states that the PV disconnecting means is not required to be suitable for use as service equipment.

Nevertheless, for a line side interconnection CPS Energy (San Antonio) requires us to bond the neutral to ground in the PV AC disco, connect them to a grounding electrode at the switch, and separate it from the existing service ground. The PV meter between the PV and the service can't have a ground going through it (only neutral) and the GEC in the MDP must be moved to a ground bar in the tap box.

DISCLAIMER: I am relating this from memory, visualizing the three line drawing CPS furnishes us to design from. I'm pretty sure the details are correct.

 

[jaggedben]

The controversy over whether a supply-side connection constitutes a service disconnecting means lies outside the scope of what I was saying above. And if one considers such a connection to be service equipment, that's still because it's a connection to the utility, not because it is a PV connection.

david is claiming, AFAICT, that the disconnecting means for a PV system connected on the load side of a normal service disconnecting means is also a kind of service equipment, by virtue of it being a power source. (And I believe he is claiming that therefore anything upstream is not part of an inverter output circuit). That is just not an idea that should be given any credence, for many reasons.

 

[GoldDigger]

david is claiming, AFAICT, that the disconnecting means for a PV system connected on the load side of a normal service disconnecting means is also a kind of service equipment, by virtue of it being a power source. (And I believe he is claiming that therefore anything upstream is not part of an inverter output circuit). That is just not an idea that should be given any credence, for many reasons.

:thumbsup:

 

[david]

http://www.youtube.com/watch?v=7vD0r_bVjuo

PV - Point of Utility Connection, 705.12 (1hr:23min:43sec)

705.12(D)(1)
“The ac connection of one or more inverters in one system must be made to a dedicated circuit breaker or fusible disconnect”

"The important thing to add to that , is the term dedicated really is intended to discuss the fact that there are no loads on this circuit. That’s the focus. Previous versions of the code did not get into the details of one or more inverters. So because of concerns of over people miss-interpreting that information and saying one inverter one overcurrent devise. Dedicated is intended to mean dedicated to nothing but generating inverters, no loads because once you start getting into loads that Muddy’s the water on overcurrent protection device and things like that. The key issue no loads "


Main Bonding Jumper250.24 (B)

Quoting Mike Holt:

“You have a disconnect on the line side of a service disconnect with service conductors in it. That’s not technically a service disconnect I’ll call it service equipment but Mike if you call it service equipment read 250.24 ( C ) it says service disconnect……….”

There needs to be clarification on what you call PV disconnect equipment with service entrance conductors in the equipment enclosure on the line side of utility service disconnect equipment.

What does article 690.2 and 705.2 mean by the term “service equipment”

 

[ggunn]

There needs to be clarification on what you call PV disconnect equipment with service entrance conductors in the equipment enclosure on the line side of utility service disconnect equipment.

Good luck with that one. Austin and San Antonio disagree diametrically.

 

[david]

david is claiming, AFAICT, that the disconnecting means for a PV system connected on the load side of a normal service disconnecting means is also a kind of service equipment, by virtue of it being a power source. (And I believe he is claiming that therefore anything upstream is not part of an inverter output circuit). That is just not an idea that should be given any credence, for many reasons.

http://www.youtube.com/watch?v=7vD0r_bVjuo "The important thing to add to that , is the term dedicated really is intended to discuss the fact that there are no loads on this circuit. ”

What I am saying is that i agree with the statement " the term dedicated really is intended to discuss the fact that there are no loads on inverter output circuit.

If there are no loads on the inverter output circuits they are the conductors that supply the PV source to the loads. The dedicated disconnect is a clear separation point from the source supply to the load distribution. The point of connection between the source and the load.

705.12 gives clear rules on what to do at the point of connection.. There are many times conductors and bussbars in series with the point of connection
and the utility source. We both agree that those series bussbars and conductors need the PV source corrections applied to them.

In 2008 there was clear direction to apply those calculations to bussbars and conductors in series

 

[GoldDigger]

What I am saying is that i agree with the statement " the term dedicated really is intended to discuss the fact that there are no loads on inverter output circuit.

If there are no loads on the inverter output circuits they are the conductors that supply the PV source to the loads. The dedicated disconnect is a clear separation point from the source supply to the load distribution. The point of connection between the source and the load.

705.12 gives clear rules on what to do at the point of connection.. There are many times conductors and bussbars in series with the point of connection
and the utility source. We both agree that those series bussbars and conductors need the PV source corrections applied to them.

In 2008 there was clear direction to apply those calculations to bussbars and conductors in series

And what we disagree firmly about is whether there is any chance of confusion between the group of wires, bus bars, etc. that are between the inverter and the service (A) and the group of wires, etc. that are between the inverter and the point of connection (B).
The wording in the relevant section of the code clearly says (A) while you insist that too many people will misinterpret this as meaning (B).
If you agree with that characterization I do not see much point in further discussion as it is not likely to change anybody's mind.

 

[jaggedben]

There needs to be clarification on what you call PV disconnect equipment with service entrance conductors in the equipment enclosure on the line side of utility service disconnect equipment.

What does article 690.2 and 705.2 mean by the term “service equipment”

I agree with your first sentence only with regard to supply-side inverter connections. There is no confusion about load-side inverter connections. Service equipment is always at the utility end of things and no where else. The term 'service equipment' is defined in article 100 and means the same thing throughout the code.

What I am saying is that i agree with the statement " the term dedicated really is intended to discuss the fact that there are no loads on inverter output circuit.

The inverter branch circuit and the inverter output circuit are not the same thing. It is the branch circuit, which is the wires between the inverter and its OCPD, which is required to be dedicated and not have loads connected to the same circuit. The section you are quoting regarding the dedicated disconnect and OCPD does not say anything about the inverter output circuit.

 

[david]

I agree with your first sentence only with regard to supply-side inverter connections. There is no confusion about load-side inverter connections. Service equipment is always at the utility end of things and no where else. The term 'service equipment' is defined in article 100 and means the same thing throughout the code.



The inverter branch circuit and the inverter output circuit are not the same thing. It is the branch circuit, which is the wires between the inverter and its OCPD, which is required to be dedicated and not have loads connected to the same circuit. The section you are quoting regarding the dedicated disconnect and OCPD does not say anything about the inverter output circuit.

https://www.google.com/url?sa=t&rct...part-1&usg=AFQjCNEt3bCpudMLc36pYhKTqfhu7YYTVw
Circuit sizing and protection

The inverter output circuit is the circuit conductors that run from the AC output terminals of the inverter to the AC disconnect.

Inverter output current. This value equals the continuous output current marked on the inverter nameplate (Fig. 2). The inverter output circuit is the circuit conductors that run from the AC output terminals of the inverter to the AC disconnect [690.2].



I going to give this some thought, it seems to make sense that the inverter output circuits would end at the connection point

its hard to find illustrations when the load side connection point is not also the service equipment

 

[ggunn]

The inverter output circuit is the circuit conductors that run from the AC output terminals of the inverter to the AC disconnect.

Sometimes the "AC disconnect" is a breaker in an AC combiner panel. You cannot have any loads on the conductors between the panel and the inverter, but you can have loads in the panel when the busbar is qualified under 705.12(D)(2)(3)(c).

 

[jaggedben]

...
The inverter output circuit is the circuit conductors that run from the AC output terminals of the inverter to the AC disconnect.

Inverter output current. This value equals the continuous output current marked on the inverter nameplate (Fig. 2). The inverter output circuit is the circuit conductors that run from the AC output terminals of the inverter to the AC disconnect [690.2].

Just because Mike Holt said something in a paraphrase doesn't mean you get to ignore what's actually written in the code.

In the examples in that article, the AC disconnect is in the service equipment so his mischaracterization of the definition is moot.

I going to give this some thought, it seems to make sense that the inverter output circuits would end at the connection point

its hard to find illustrations when the load side connection point is not also the service equipment

There are some in this other video you already posted.
https://www.youtube.com/watch?v=7vD0r_bVjuo

 

[david]

Never mind

 

[david]

Never mind

in large the image

 

[ggunn]

Never mind

Can't read it; too small.

 

[david]

I'm not going to agree that the inverter output circuits extend past the connection point (past the source disconnect) I do see why you guys it does. And based on that you do not believe any further direction to apply the source calculations to conductors and bussbars in series with the inverter output circuits to the utility service equipment is needed. Your position is you have to apply those calculations by utility inverter output circuits to all of the series equipment.

My position is that the inverter output circuits end at the connection point where load distribution begins.

On a line side connection point at load side of the utility meter I would define the inverter output circuits to end at that connection point. You may define the service entrance conductors as inverter output circuit. I would not and do not see why they should be subject to the 125% of the sum of the inverters output circuits calculation for continuous loading.

You guys may respond, but I’m kind of done discussing my point of view. You all said a lot and I will revisit your post in this thread and give it much thought.

Thank you all so very much.

 

[david]

enlarged