Is it a PV Disconnect or a PV Service Disconnect?

[shortcircuit2]

I know we have discussed this before but 2 leading industry experts are calling it different.

I'm referring to the 1st disconnect for a Supply Side Connection of a Photovoltaic Power Source at a building with a utility supply.

1. In the EC&M article on page 33 of the OCT. 2013 issue Mike Holt defines it as the Photovoltaic System Disconnect and says that bonding the grounded conductor and raceways on line side connections in only "suggested".

2. In the IAEI article on page 60 of the Nov/Dec 2013 issue John Wiles defines it as the Photovoltaic Service Disconnect and says all chapter 2 service requirements "should" apply such as bonding the grounded conductor and raceways along with the rest of requirements for service disconnects.

I have stated my position before with regard to this and side with John Wiles but feel the "should" must be replaced with "Shall"

Why be so indecisive on this issue? Why leave it open to interpretation? The code needs more concise language on this issue.

If there is a Supply Side Connection to a Utility Supply, the conductors and equipment between the connection and the disconnect are subject to the Available Fault Current of the Utility Supply and must be treated as we treat all other connections to a Utility Supply and subject to the rules for services in article 230 of the NEC.

 

[GoldDigger]

I know we have discussed this before but 2 leading industry experts are calling it different.

I'm referring to the 1st disconnect for a Supply Side Connection of a Photovoltaic Power Source at a building with a utility supply.

1. In the EC&M article on page 33 of the OCT. 2013 issue Mike Holt defines it as the Photovoltaic System Disconnect and says that bonding the grounded conductor and raceways on line side connections in only "suggested".

2. In the IAEI article on page 60 of the Nov/Dec 2013 issue John Wiles defines it as the Photovoltaic Service Disconnect and says all chapter 2 service requirements "should" apply such as bonding the grounded conductor and raceways along with the rest of requirements for service disconnects.

I have stated my position before with regard to this and side with John Wiles but feel the "should" must be replaced with "Shall"

Why be so indecisive on this issue? Why leave it open to interpretation? The code needs more concise language on this issue.

If there is a Supply Side Connection to a Utility Supply, the conductors and equipment between the connection and the disconnect are subject to the Available Fault Current of the Utility Supply and must be treated as we treat all other connections to a Utility Supply and subject to the rules for services in article 230 of the NEC.

I agree 100% that the disconnect must be SUSE, and that the conductors to the disconnect need to be treated in the same way any service conductors would be.
The only slight concern that I have is with the ground to neutral bonding when the disconnect is remote from the "normal" service disconnect and bond point.
But my concern about that is not enough to justify special treatment.

 

[Smart $]

I know we have discussed this before but 2 leading industry experts are calling it different.

I'm referring to the 1st disconnect for a Supply Side Connection of a Photovoltaic Power Source at a building with a utility supply.

1. In the EC&M article on page 33 of the OCT. 2013 issue Mike Holt defines it as the Photovoltaic System Disconnect and says that bonding the grounded conductor and raceways on line side connections in only "suggested".

2. In the IAEI article on page 60 of the Nov/Dec 2013 issue John Wiles defines it as the Photovoltaic Service Disconnect and says all chapter 2 service requirements "should" apply such as bonding the grounded conductor and raceways along with the rest of requirements for service disconnects.

I have stated my position before with regard to this and side with John Wiles but feel the "should" must be replaced with "Shall"

Why be so indecisive on this issue? Why leave it open to interpretation? The code needs more concise language on this issue.

If there is a Supply Side Connection to a Utility Supply, the conductors and equipment between the connection and the disconnect are subject to the Available Fault Current of the Utility Supply and must be treated as we treat all other connections to a Utility Supply and subject to the rules for services in article 230 of the NEC.

First off, the term "Photovoltaic Service Disconnect" is a misonomer. Under code, the are separate requirements for photovoltaic system and service disconnecting. 690.14(A) explicitly states the PV system disconnect shall not be required to be suitable as service equipment. That additionally implies the PV system disconnect is not also a service disconnect. However, when the point of connection is the supply side of the service disconnect(s), the conductors on the service side of the PV system disconnect must meet the requirements for service wiring methods.

 

[jaggedben]

First off, the term "Photovoltaic Service Disconnect" is a misonomer. ...

It seems a decent enough term for when the disconnect serves both purposes and must meet both sets of requirements.

I agree with the OP that the code ought to be amended to explicitly clarify the issue. People's opinions, however logical are not, are based on interpretations of implicit language. FWIW, I too am in the John Wiles camp and not the Mike Holt camp.

 

[c_picard]

First off, the term "Photovoltaic Service Disconnect" is a misonomer. Under code, the are separate requirements for photovoltaic system and service disconnecting. 690.14(A) explicitly states the PV system disconnect shall not be required to be suitable as service equipment. That additionally implies the PV system disconnect is not also a service disconnect. However, when the point of connection is the supply side of the service disconnect(s), the conductors on the service side of the PV system disconnect must meet the requirements for service wiring methods.

690.14(A) was never intended to apply to disconnects on the AC side, see the 2011 and 2014 NEC. The "additional provisions" apply to 690.13, and the most recent cycles attempt to add some clarification here.

"690.13 All Conductors.Means shall be provided to disconnect all current-carrying DC conductors of a photovoltaic system from all other conductors in a building or other structure."

Show me an inspector that would pass a plastic pull-out style, non service rated, 30A disconnect like the one you would see on an AC condenser, used as the disconnect for a supply side connection. I certainly wouldn't pass it. I agree, PV Service Disconnect is not a defined term in the NEC; we are talking about an additional SERVICE DISCONNECT, period. It shouldn't make any difference what is on the load side of it, to be safe, it's what is on the LINE side we should be worried about.

Riddle me this...if we are adding an additional "SET OF SERVICE ENTRANCE CONDUCTORS" (yes, this is clearly what they are called per the NEC), then what do we use to disconnect them? HINT: A SERVICE DISCONNECT.

+1 for Team Wiles.

 

[Smart $]

...

Riddle me this...if we are adding an additional "SET OF SERVICE ENTRANCE CONDUCTORS" (yes, this is clearly what they are called per the NEC), then what do we use to disconnect them? HINT: A SERVICE DISCONNECT.

...

There is nowhere in the Code that actually calls it a service disconnect.

Riddle me this considering the following:

230.40 says....

Exception No. 5: One set of service-entrance conductors
connected to the supply side of the normal service disconnecting
means shall be permitted to supply each or several
systems covered by 230.82(5) or 230.82(6).

230.82(6) ...

Solar photovoltaic systems, fuel cell systems, or interconnected
electric power production sources.

The title of 230.82 is "Equipment Connected to the Supply Side of Service Disconnect."

If you call the PV System disconnect a Service Disconnect, the PV system would not be connected to the supply side of the Service Disconnect.

 

[shortcircuit2]

If you call the PV System disconnect a Service Disconnect, the PV system would not be connected to the supply side of the Service Disconnect.

I don't follow your line of thinking here.

230.40 Exception #5 tells us of connections allowed ahead of the normal service disconnecting means.

230.82 Ex#5 covers it well by saying "if provided with service equipment" This gives the industry concise direction on how it should be installed.

230.82 Ex#6 opens the door for different interpretation in the industry as we all have seen.

If 230.86 Ex#6 said this... "Solar photovoltaic systems, fuel cell systems, wind electric systems, or interconnected power production systems, if provided with service equipment and installed in accordance with the requirements for service-entrance conductors."

Then there would be unquestioned direction for the industry.IMO

shortcircuit

 

[GoldDigger]

There is nowhere in the Code that actually calls it a service disconnect.

Riddle me this considering the following:

230.40 says....




230.82(6) ...


The title of 230.82 is "Equipment Connected to the Supply Side of Service Disconnect."

If you call the PV System disconnect a Service Disconnect, the PV system would not be connected to the supply side of the Service Disconnect.

Only if the PV Service Disconnect is considered to be part of the PV system rather than a platypus located between the service conductors and the PV system.

 

[ggunn]

Only if the PV Service Disconnect is considered to be part of the PV system rather than a platypus located between the service conductors and the PV system.

Autocorrect?

 

[GoldDigger]

Autocorrect?

Nope. A reference to the oddness of the platypus.
My son has a t-shirt with an illustration of a platypus and the legend: "Evolution! Go home you're drunk."

 

[Smart $]

Only if the PV Service Disconnect is considered to be part of the PV system rather than a platypus located between the service conductors and the PV system.

But there is no "PV Service Disconnect" term in the Code. You can play on the English language and call it a "PV System-Service" disconnect, and even shorten that to "PV-Service" disconnect... but it will not change the fact that PV Service Disconnect is not in the NEC. I prefer to simply call it a PV System disconnect.

 

[GoldDigger]

But there is no "PV Service Disconnect" term in the Code. You can play on the English language and call it a "PV System-Service" disconnect, and even shorten that to "PV-Service" disconnect... but it will not change the fact that PV Service Disconnect is not in the NEC. I prefer to simply call it a PV System disconnect.

Thanks for catching my typo. I hope it did not detract too much from what I meant to say.

 

[Smart $]

I don't follow your line of thinking here.

...

My line of thinking is simple logic...

If you call the disconnect at the end of those permitted service-entrance conductors a Service Disconnect, then the PV System would be connected to the load side of the Service Disconnect... not the supply side.

 

[Zee]

But there is no "PV Service Disconnect" term in the Code. You can play on the English language and call it a "PV System-Service" disconnect, and even shorten that to "PV-Service" disconnect... but it will not change the fact that PV Service Disconnect is not in the NEC. I prefer to simply call it a PV System disconnect.

1.
It is a "service disconnect" if line side tied to utility. I think that is clear!:roll:

We just want to disambiguate it from any other possible service disco.... by adding the wording, "PV".
I am not sure anyone means anything beyond clarifying that, "This here is the service disco for the pv"..... and not the bldg, house or whatever the other service(s) is /are.
You could have "House service disconnect", "Rear Unit Service Disconnect" etc.
2.
I don't think anyone thinks this is a defined NEC term, do they?
3.
Agreed, the PV Sys Disco is not a Service Disconnect NECESSARILY...but it could be, right? If you meet req.s for both, no reason it cannot do double duty.

 

[Zee]

Conductors from ANY grid-tie PV system should be connected to the LOAD terminals on ANY switchgear.
Utility should be connected to LINE terminals.
(whether termed Service Disco or System disco or AC Disco, no matter.)

Through-out the complete "Inverter Output Circuit".

 

[Smart $]

1.
It is a "service disconnect" if line side tied to utility. I think that is clear!:roll:

We just want to disambiguate it from any other possible service disco.... by adding the wording, "PV".
I am not sure anyone means anything beyond clarifying that, "This here is the service disco for the pv"..... and not the bldg, house or whatever the other service(s) is /are.
You could have "House service disconnect", "Rear Unit Service Disconnect" etc.
2.
I don't think anyone thinks this is a defined NEC term, do they?
3.
Agreed, the PV Sys Disco is not a Service Disconnect NECESSARILY...but it could be, right? If you meet req.s for both, no reason it cannot do double duty.

It's not worth arguing the semantics. You can call it whatever you want from a slang perspective and I could care less. The only issue I'm concerned with proper terminology for communicating Code issues. When you call it a Service Disconnect (short for Service Equipment - Disconnecting Means), it presents problems for the proper application of Code. When you call it a PV System disconnect, there is no ambiguity in the application of Code.

If you add a load, or otherwise distinguish the potential for loads on the PV side of this disconnect, then it is a Service Disconnect and not a PV System disconnect. The PV system would then be connected to the load side of the distribution system and must comply with different set of requirements (refer to 705.12). You would also have to provide a required PV System disconnect other than the disconnect of issue.

Additionally, no "service" is provided to the PV System.

 

[shortcircuit2]

My line of thinking is simple logic...

If you call the disconnect at the end of those permitted service-entrance conductors a Service Disconnect, then the PV System would be connected to the load side of the Service Disconnect... not the supply side.

But the code (230.40ex#5) refers to the allowed supply side connection as a connection to the supply side of the NORMAL service disconnecting means. That's all.

With your logic, there would be no disconnect at all to be LINE side connected.

 

[Smart $]

...
With your logic, there would be no disconnect at all to be LINE side connected.

That is not correct. A PV System disconnect is required.

 

[texie]

I know we have discussed this before but 2 leading industry experts are calling it different.

I'm referring to the 1st disconnect for a Supply Side Connection of a Photovoltaic Power Source at a building with a utility supply.

1. In the EC&M article on page 33 of the OCT. 2013 issue Mike Holt defines it as the Photovoltaic System Disconnect and says that bonding the grounded conductor and raceways on line side connections in only "suggested".

2. In the IAEI article on page 60 of the Nov/Dec 2013 issue John Wiles defines it as the Photovoltaic Service Disconnect and says all chapter 2 service requirements "should" apply such as bonding the grounded conductor and raceways along with the rest of requirements for service disconnects.

I have stated my position before with regard to this and side with John Wiles but feel the "should" must be replaced with "Shall"

Why be so indecisive on this issue? Why leave it open to interpretation? The code needs more concise language on this issue.

If there is a Supply Side Connection to a Utility Supply, the conductors and equipment between the connection and the disconnect are subject to the Available Fault Current of the Utility Supply and must be treated as we treat all other connections to a Utility Supply and subject to the rules for services in article 230 of the NEC.

You may recall from the previous thread on this that I feel there is no question that you must bond the grounded conductor in this situation. I agree that "should" is not a strong enough word. To not bond could lead to catastrophic results in the right circumstances.
At the risk of offending others, I think most are to hung up on the code technicalities of whether this is a PV disco. or a service disco. rather than the electrical realities of this. That said, I think the NEC needs to address this.
+1 for John Wiles view.

 

[shortcircuit2]

It's not worth arguing the semantics. You can call it whatever you want from a slang perspective and I could care less. The only issue I'm concerned with proper terminology for communicating Code issues. When you call it a Service Disconnect (short for Service Equipment - Disconnecting Means), it presents problems for the proper application of Code. When you call it a PV System disconnect, there is no ambiguity in the application of Code.

If you add a load, or otherwise distinguish the potential for loads on the PV side of this disconnect, then it is a Service Disconnect and not a PV System disconnect. The PV system would then be connected to the load side of the distribution system and must comply with different set of requirements (refer to 705.12). You would also have to provide a required PV System disconnect other than the disconnect of issue.

Additionally, no "service" is provided to the PV System.

The problem with just calling it a "PV System Disconnect" is some may think the disconnect would not need important safety features such a grounded conductor connection to the disconnect switch...or a main bonding jumper. If it is not a AC supplied service then those are not required...right.

Any supply side connected PV System would still be subject to the 705.12...both supply side and load side.

It is a Service. Inverters use power...data acquisition systems use power, all supplied to the premises wiring system by the serving utility. Without Service a Grid Tied PV system will not work.

That's my logic...