Change to 2017 690.13(C) makes supply side interconnection a service entrance?

[pv_n00b]

I know a number of people point to 690.13(C) to show that the NEC is implying that a PV supply side interconnection does not need to be treated as a service entrance. Section 690.13(C) in 2014 states:

(C) Suitable for Use. Each PV system disconnecting means shall not be required to be suitable as service equipment.

The new wording in 2017 is:

(C) Suitable for Use. If the PV system is connected to the supply side of the service disconnecting means as permitted in 230.82(6), the PV system disconnecting means shall be listed as suitable for use as service equipment.

While the NEC does not explicitly state if the supply side interconnection is a service entrance of a feeder tap this change would seem to indicate that they have changed the implied direction from feeder tap to service entrance. Why else have the disconnect rated for use as a service entrance if it's not also implied to install it as a service entrance? Why make the change?

 

[ggunn]

I know a number of people point to 690.13(C) to show that the NEC is implying that a PV supply side interconnection does not need to be treated as a service entrance. Section 690.13(C) in 2014 states:

(C) Suitable for Use. Each PV system disconnecting means shall not be required to be suitable as service equipment.

In the 2014 NEC, 690.13 appears to me to apply only to DC conductors.

 

[jaggedben]

And we move forward to ... the same place we started.

@pv_noob

If you look at the new language for rapid shutdown, I think you'll find something that can be used to argue the opposite.

And the 690.13 language you mention could, in a twisted way, be used to argue the opposite of what you've said. Obviously a service disconnect has to meet the requirements of article 230. So why would they have updated that part of 690.13 if the disconnect was already a service disconnect? It would have gone without saying.

The one thing that I suppose might come into play now is following the listing instructions on service equipment, but I'm not sure that will ever have a real bearing on requirements.

To be clear, I generally treat supply side connections as service disconnects. But I looked through 690 and 705 when I got my 2017 NEC and I don't believe we are any closer to resolving the question of what the code thinks than we were before.

 

[Carultch]

And we move forward to ... the same place we started.

@pv_noob

If you look at the new language for rapid shutdown, I think you'll find something that can be used to argue the opposite.

And the 690.13 language you mention could, in a twisted way, be used to argue the opposite of what you've said. Obviously a service disconnect has to meet the requirements of article 230. So why would they have updated that part of 690.13 if the disconnect was already a service disconnect? It would have gone without saying.

The one thing that I suppose might come into play now is following the listing instructions on service equipment, but I'm not sure that will ever have a real bearing on requirements.

To be clear, I generally treat supply side connections as service disconnects. But I looked through 690 and 705 when I got my 2017 NEC and I don't believe we are any closer to resolving the question of what the code thinks than we were before.

What I still don't understand, is whether or not we should be bonding neutral and ground in the first disconnect for a connection on the supply-side service disconnecting means. Bearing in mind that it is also already bonded, at the existing service disconnecting means. This is not one of those cases where you could install it out of ignorance, regardless of if needed or not, and be all set. Because bonding of neutral and ground where not needed, is incorrect.

 

[GoldDigger]

And ggunn has given examples of two different jurisdictions in Texas that take exactly opposite views on whether to bond at the supply side PV disconnect or not.

Sent from my XT1585 using Tapatalk

 

[jaggedben]

What I still don't understand, is whether or not we should be bonding neutral and ground in the first disconnect for a connection on the supply-side service disconnecting means. Bearing in mind that it is also already bonded, at the existing service disconnecting means. This is not one of those cases where you could install it out of ignorance, regardless of if needed or not, and be all set. Because bonding of neutral and ground where not needed, is incorrect.

What I always say ... put in the bond, then take it out if the inspector doesn't like it.

 

[pv_n00b]

And we move forward to ... the same place we started.

@pv_noob

If you look at the new language for rapid shutdown, I think you'll find something that can be used to argue the opposite.

And the 690.13 language you mention could, in a twisted way, be used to argue the opposite of what you've said. Obviously a service disconnect has to meet the requirements of article 230. So why would they have updated that part of 690.13 if the disconnect was already a service disconnect? It would have gone without saying.

The one thing that I suppose might come into play now is following the listing instructions on service equipment, but I'm not sure that will ever have a real bearing on requirements.

To be clear, I generally treat supply side connections as service disconnects. But I looked through 690 and 705 when I got my 2017 NEC and I don't believe we are any closer to resolving the question of what the code thinks than we were before.

I don't think there is a resolution either. But maybe just a hint. Isn't the only thing that makes a service entrance rated disconnect different from a non-service entrance rated disconnect the built in ability to apply a system bond? I'm wondering why they would call specifically for equipment that provides a system bond without then expecting anyone to use it. It seems strange. What would be the point?

 

[pv_n00b]

In the 2014 NEC, 690.13 appears to me to apply only to DC conductors.

You are correct, but I've never seen that deter anyone from using that section to argue that a supply side interconnection is not a service entrance.

 

[shortcircuit2]

Isn't the only thing that makes a service entrance rated disconnect different from a non-service entrance rated disconnect the built in ability to apply a system bond?

Yup

I'm wondering why they would call specifically for equipment that provides a system bond without then expecting anyone to use it. It seems strange. What would be the point?

If they don't call it a service disconnect when it is the 7th switch...they don't need to go though the expense of adding a new main switch.

 

[Carultch]

Yup



If they don't call it a service disconnect when it is the 7th switch...they don't need to go though the expense of adding a new main switch.

If it is on the DC side, the ability to bond neutral to ground is irrelevant. In fact, in the new NEC, we are now required to cut both polarities through disconnect blades in most topologies. So the neutral kit cannot even be used, when using an AC disconnect as a DC disconnect. Yes, I'm aware a derate or a multiple poles in series rule comes in to play.

 

[pv_n00b]

Yup



If they don't call it a service disconnect when it is the 7th switch...they don't need to go though the expense of adding a new main switch.

But if a service entrance rated disconnect is installed but not installed as a service disconnect with the system bond can it still be called a service disconnect? I would not think so. But it looks like PV system supply side interconnection have been established as not part of the 6 disconnect count for the existing electrical service either way.

 

[jaggedben]

But if a service entrance rated disconnect is installed but not installed as a service disconnect with the system bond can it still be called a service disconnect? I would not think so.

If you call it a service disconnecting means then a bunch of code sections come into play (e.g. 250.24(C)) and I think you have to bond. If you don't call it a service disconnecting means then I guess anything goes; I'm really not sure what says you shouldn't bond, besides 250.6, but it's not logical to apply 250.6 in one situation and not the other. It will make no difference to anyone's safety.

I'm not sure what to think about this notion that if you install a suitable-for-use-as-service-equipment but don't bond the neutral that it is no longer suitable, or no longer a service disconnect. I wonder what UL would say about the suitability part. If UL says it's not suitable without the bond then the new 690.13 would seem to be effectively saying you have to bond and would seem to contravene 250.6.

But it looks like PV system supply side interconnection have been established as not part of the 6 disconnect count for the existing electrical service either way.

To me that is a whole other ball of wax from bonding, and I don't exactly agree. Personally I think the most liberal interpretation for a 7th handle requires it to be in a separate enclosure. In practice, labeling often enforces that.

...

I still think that if it were not for a handful of bugaboo words in Article 100 that most people would consider supply side connections to be service disconnecting means. The 2017 code has not changed those words.

 

[c_picard]

Agreed.

There also seems to be a few folks that remember back to when J.Wiles was trying to introduce language that would have implied PV was a second service. Totally botched that in my opinion, with lasting repercussions.

In addition to the outdated definition - After many hours and countless conversations on this, I think I finally have it nailed down to one question that needs answering in order to understand the hangup towards considering the PV disconnect a service disconnecting means:

Why would a service configured in accordance with 230.40, Exception 2, be installed ANY differently than one configured in accordance with Exception 5? From both a practical and an engineering standpoint, they'd look EXACTLY the same.

I've got a draft of a whitepaper on this, PM me if anyone would like to give it a read and comment.

 

[ggunn]

To cloud things even further, some jurisdictions require that the AC disco in a supply side interconnection be suitable as service equipment, but they do not require that it be wired as a service entrance.