690 or 705 sections that need changes for the 2020 NEC cycle?

[PVfarmer]

Originally Posted by ggunn I would like the NEC to declare one way or the other whether or not an AC disco on a supply side connected PV system needs a neutral to ground bond, with all that entails. Some AHJs say yes, others say no.

So would I. I’ll see what I can bring up to make it more declarative. I’ll tell you though, I’ve brought this up before and some people seem to think it’s clear that it is not a service entrance so they block adding any wording to that effect.

It seems clear to me that an AC PV disco is part of the service entrance- I think it is at the "load end" of the service entrance, and it is service equipment.
It has service conductors or service entrance conductors on the grid side, and PV output conductors on the PV side, and it cuts off the PV from the grid.

But it could be clearer for sure.
Service conductors and service entrance conductors are defined in code- I don't see where "service entrance" is used by itself without conductors right after.

NatGrid says this-
Service entrance:
That part of the Customer's wiring from the point of attachment or termination
of the service lateral or service line to and including the service equipment.

^^ That means service entrance = everything from drip loop (when overhead) to breakers or fuses.

These defs. are 2017 code, Art.100.
One thought is that the _______ after load end of service conductors might say... "or load end of service entrance conductors"?
The service entrance conductors are a subset of service conductors, and the former is not always part of the setup.
I like that Info Note at the bottom
---
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.

Service Conductors.
The conductors from the service point to the service disconnecting means.

Service Conductors, Overhead. The overhead conductors
between the service point and the first point of connection
to the service-entrance conductors at the building or other
structure.

Service Conductors, Underground. The underground conductors
between the service point and the fIrst point of connection
to the service-entrance conductors in a terminal box,
meter, or other enclosure, inside or outside the building wall.
Informational Note: Where there is no terminal box, meter,
or other enclosure, the point of connection is considered to
be the point

Service-Entrance Conductors, Overhead System.
The service conductors between the terminals of the service
equipment and a point usually outside the building, clear of
building walls, where joined by tap or splice to the service
drop or overhead service conductors.

Service-Entrance Conductors, Underground System.
The service conductors between the terminals of the service
equipment and the point of connection to the service lateral
or underground service conductors.

Informational Note: Where service equipment is located
outside the building walls,there may be no service entrance
conductors or they may be entirely outside the
building.
(my note, as in: a supply side PV system OCPD and j-box, outside...or...a MDP for a house, outside- no service entrance.
When PV OCPD/j-box are outside and house MDP is inside, it's service entrance conductors to house, service conductors to PV OCPD)

 

[ggunn]

It seems clear to me that an AC PV disco is part of the service entrance- I think it is at the "load end" of the service entrance, and it is service equipment.
It has service conductors or service entrance conductors on the grid side, and PV output conductors on the PV side, and it cuts off the PV from the grid.[big ol' snip]

Hence my point; many others see it differently.

Just a tip: when you just cut and paste large blocks of text into a post I doubt many read it. I know I don't.

 

[ggunn]

So would I. I’ll see what I can bring up to make it more declarative. I’ll tell you though, I’ve brought this up before and some people seem to think it’s clear that it is not a service entrance so they block adding any wording to that effect.

Others seem to think it's clear that it IS a service entrance. I don't understand why they would block wording that would make it clear, either way they want it to be. I really don't care which.

 

[PVfarmer]

the NEC to declare one way or the other whether or not an AC disco on a supply side connected PV system needs a neutral to ground bond,

Just a tip: when you just cut and paste large blocks of text into a post I doubt many read it. I know I don't.

Others seem to think it's clear that it IS a service entrance

I think it does declare that a N-G bond is required, but since you don't care what I have to say, why bother?

I'm pasting the code being referenced so people don't have to look it up somewhere else.
If you want to ignore it and not argue, great!

But you could show this pic to people who think a switch is a "service entrance", and point out that the service entrance goes from the grid side of the overhead drip loop/underground service point to the load side of the service equipment.
You could also point out that the code does NOT define "service entrance", period.
It defines service entrance CONDUCTORS, overhead and underground.

It just seems so glaringly obvious to me that the PV OCPD switch is simply service equipment with service conductors on the grid side and protected PV output conductors on the PV side.

Edit:Imagine this pic is showing a PV system to grid, and no house loads are involved.
How could you possibly say the PV switch isn't service equipment?

 

[Smart $]

...
It just seems so glaringly obvious to me that the PV OCPD switch is simply service equipment with service conductors on the grid side and protected PV output conductors on the PV side.
...

The term service in this context originates from the utility providing electrical energy to a consumer, i.e. the utility provides the "service" and the customer consumes the "service". In the case of a supply-side PV POC, there is no "service".

 

[ggunn]

I think it does declare that a N-G bond is required, but since you don't care what I have to say, why bother?

I have to say that you've got that right; I really don't care. There is only one AHJ in Texas that I have dealt with so far who requires a N-G bond in the disco, and the NEC is ambiguous on the question. I can see that your interpretation is that it is required, but that is your interpretation, not an explicit statement in the Code, and by my lights your interpretation of the Code sometimes leaves something to be desired.

Personally, I don't care which way it goes; it's just a pain to find out what an AHJ expects, and some of them have never thought about it.

 

[PVfarmer]

The term service in this context originates from the utility providing electrical energy to a consumer, i.e. the utility provides the "service" and the customer consumes the "service". In the case of a supply-side PV POC, there is no "service".

The service begins where conductors are connected to the POCO's xfmr, and ends at the load side terminals of the service equipment.
Supply side PV is connected to the service conductors or service entrance conductors which lead to service equipment for utilization loads.

A- Service conductors and PV output conductors are all part of the premises wiring.

B- I see what you mean, the NEC "service" definition doesn't mention PV, yet PV and grid are both "delivering electric energy ... to the wiring system of
the premises". So that strikes me as weird. Nevertheless, the "service connection" in the NatGrid pic, which I would take to mean the same as service, is everything from POCO xfmr terminals to load side terminals of service equipment.
NatGrid's defintion for service could even include their xfmr...

Also, the service entrance = things in bold.

C- A PV system is defined as everything producing power "suitable for connection to a utilization load".
I think it is connected where the switch is. If somebody opens the switch, the PV is no longer connected to the load (or utility...) :blink:

===

A
Premises Wiring (System). Interior and exterior wiring,
including power, lighting, control, and signal circuit wiring
together with all their associated hardware, fittings, and
wiring devices, both permanently and temporarily installed.
This includes (a) wiring from the service point or power
source to the outlets or (b) wiring from and including the
power source to the outlets where there is no service point.
Such wiring does not include wiring internal to appliances,
luminaires, motors, controllers, motor control centers,
and similar equipment.
Informational Note: Power sources include, but are not
limited to, interconnected or stand-alone batteries, solar
photovoltaic systems, other distributed generation systems,
or generators.

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

NatGrid
Service:
The conductors and equipment for delivering energy from the Company's distribution line
to the wiring system of the Customer served.

Service Cable.
Service Conductors.
Service Conductors, Overhead.
Service Conductors, Underground.
Service Drop.
("service entrance" not present)
Service-Entrance Conductors, Overhead System.
Service-Entrance Conductors, Underground System.
Service Equipment.
Service Lateral.
Service Point.

C
Photovoltaic (PV) System. The total components and subsystem
that, in combination, convert solar energy into electric
energy suitable for connection to a utilization load.

 

[PVfarmer]

I have to say that you've got that right; I really don't care.

Well the first part is encouraging...

So what do you think about this diagram?
Forget about which conductors are called what- just the green parts.
We're supposed to bond N to G at the first disconnecting means.

Does the diagram show that correctly? I think so... Yes there are 2 "means", but they are both the first.

 

[PVfarmer]

I simply don't understand how anybody can read this in the context of a PV disco:
Art. 100
Accessible, Readily (Readily Accessible). Capable of being
reached quickly for operation, renewal, or inspections
without requiring those to whom ready access is requisite
to actions such as to use tools, to climb over or remove
obstacles, or to resort to portable ladders, and so forth.

And then think that emergency equipment *inside* a house is readily accessible to the people who want to use it.

Here is why it is confusing- when the DC disco is remotely operated by the AC PV disco, it is both ok for the DC to be inside, and the accessibility of the DC switch is irrelevant when you are not operating it directly.

705.12 says zilch about the (AC) disco being allowed indoors, which is easily fixed by adding one word.

Check out the link below-
I'm not sure if y'all are saying the "service OCD" doesn't exist with supply side PV, or that a limiter would = the service OCD, but...
A limiter is definitely not a switch!

So again, I think the fact that 705.12 does *not* say indoors is allowed, means that it isn't, so it should say so.

III. Disconnecting Means
690.13 Building or Other Structure Supplied by a PhotovoltaicSystem.
Means shall be provided to disconnect
all ungrounded dc conductors of a PV system from all other
conductors in a building or other structure.
(A) Location. The PV disconnecting means shall be jnstalled
at a readily accessible location either on the outside
of a building or structure or inside nearest the point of
entrance of the system conductors.

705.22 Disconnect Device. The disconnecting means for
ungrounded conductors shall consist of a manually or
power operable switch(es) or circuit breaker(s) with the
following features:
(I) Located OUTDOORS where readily accessible...

(...and then...why not "adjacent to the meter if possible", where the POCO wants a switch?!?)
----
Readily Accessible
What And Where In The NEC


This phrase is used to describe the location of circuit breakers, for example, permitting ready access to turn the circuit off during times of emergency, when something malfunctions, or when working on the circuit or the electrical equipment in a de-energized condition, as normally required by NFPA 70E.

However, the readily accessible requirement does not apply to all overcurrent devices. There are four exceptions to this rule: 


1. For busways
2. For supplementary overcurrent protection in accordance with 240.10
3. For overcurrent devices in accordance with 225.40 where the feeder devices are not readily accessible if the branch-circuit devices are readily accessible and the same for service overcurrent devices are not readily accessible where the feeder or branch-circuit overcurrent devices are readily accessible

http://www.ecmag.com/section/codes-standards/readily-accessible

 

[jaggedben]

You should look at the 2017 version of the definition where they specifically excluded keys from the tools that are prohibited. It really does not make sense to broadly consider inside locations to be not readily accessible when there are plenty of facilities that have people inside the 24hrs a day. Even assuming that the inside of a building would be locked when no one is there isn't perfectly logical. There are a lot if items that code requires to be readily accessible that it doesn't make sense to broadly require be outside.

So again, I think the fact that 705.12 does *not* say indoors is allowed, means that it isn't, so it should say so.

Absolutely not. If the code doesn't explicitly require something then it's not required. The code can't possibly list every way of doing something that is allowed.

 

[PVfarmer]

1 You should look at the 2017 version of the definition where they specifically excluded keys...

2 It really does not make sense to broadly consider inside locations to be not readily accessible when there are plenty of facilities that have people inside the 24hrs a day.

3 Even assuming that the inside of a building would be locked when no one is there isn't perfectly logical.

4 There are a lot if items that code requires to be readily accessible that it doesn't make sense to broadly require be outside.

5 The code can't possibly list every way of doing something that is allowed.

1 Yes, that makes it worse.
Info note: "Use of keys is a common practice under controlled or supervised conditions..."

2 I'd say the majority of residences are not controlled or supervised 24/7.

3 Well, sure, I don't lock my doors. But...most people do?
Assuming PV always =commercial locations doesn't make sense.

4 Well, yes of course. That's why "readily accessible" isn't a good term in 705.22 for something which should be outside!
705.22 doesn't specify in or outside, when it should. I have no idea what the benefit of switch/inside is.

What good is a plaque with the location of the PV disco if that disco is inside a locked, burning building??
Dropping "readily" would also work.

705.22 Disconnect Device. The disconnecting means for
ungrounded conductors shall consist of a manually or
power operable switch(es) or circuit breaker(s) with the
following features:
(I) Located OUTDOORS and readily accessible to emergency personnel at all times.

5 It can list some- 230.30(B) is a list of conduit/cable allowed for underground service.

 

[jaggedben]

If that green word is a proposal, I disagree in the most vociferous terms. For the following reasons:

1) for a load side connection, the service disconnecting means will safely do the job of de-energizing the PV output conductors as well as everything else connected to the service. There is no reason for the PV disconnect to be outside if the service disconnect is already outside, for example.

2) For a supply side connection, there is no reason the standards for the PV disconnect should be more stringent than those for other service disconnects (whether you regard the PV disco as officially another service disco or not).

3) Just because you can imagine in your head a situation where it might be seem dangerous or inconvenient doesn't mean that it's a real world problem that justifies a new code requirement that makes potentially millions of projects more difficult and expensive. You need some substantiation in the form of statistics or at least real world anecdotes. There are millions and millions of buildings across the country with service disconnecting means inside, and it's not causing people to die everyday as far as I know. If it concerns you, you are all by all means free to follow a more stringent standard for any projects you do yourself.

 

[PVfarmer]

If that green word is a proposal, I disagree in the most vociferous terms. For the following reasons:

1) for a load side connection, the service disconnecting means will safely do the job of de-energizing the PV output conductors as well as everything else connected to the service. There is no reason for the PV disconnect to be outside if the service disconnect is already outside, for example.

2) For a supply side connection, there is no reason the standards for the PV disconnect should be more stringent than those for other service disconnects (whether you regard the PV disco as officially another service disco or not).

3) Just because you can imagine in your head a situation where it might be seem dangerous or inconvenient doesn't mean that it's a real world problem that justifies a new code requirement that makes potentially millions of projects more difficult and expensive. You need some substantiation in the form of statistics or at least real world anecdotes. There are millions and millions of buildings across the country with service disconnecting means inside, and it's not causing people to die everyday as far as I know. If it concerns you, you are all by all means free to follow a more stringent standard for any projects you do yourself.

Ok, my OUTSIDE suggestion could actually be redundant along with "accessible to emergency personnel."
Or, not, seeing as we are 3 people separated by a few thousand miles yet we seem to read things as if from different planets!
Dropping READILY from 705.22...I did say "Dropping "readily" would also work."

Accessible (as applied to equipment). Admitting close
approach; not guarded by locked doors, elevation, or other
effective means.


1- But if the service disco is not outdoors, and the service disco for a load side connected residential PV system is inside a house, and therefore may be behind a key, it is the one service disconnect, and it's great that it's readily accessible- but is is not in fact the PV disco.
I realize that if you flip that breaker the PV shuts itself off- but I for one am talking about emergencies/malfunctions.

I mean wow- if a house with a PV system happens to be on fire it could have *NOTHING* at all to do with the PV, but we run into the house to hit the MDP breaker to shut down the PV? Why?

I think it should be "just plain" accessible.
In this diagram ( https://www9.nationalgridus.com/non_html/DG_sample_1line_A.pdf ), there is a switch called:
Exterior AC Utility Disconnect Switch
###A, ###VAC
(Located Adjacent to Utility Meter)

Obviously it it outdoors, yet notice it isn't called a PV disco *or* a service disco, it has no fuses, but it's the switch I'm talking about.

Basically all I'm trying to get across is that if you put a fused AC PV switch within 10 feet of an outdoor meter or service entrance, you are good to go.
It could be the difference between a double lugged meter or j-box.
Double lug seems simpler to me.

2- I didn't say "more stringent", I said clearer and in fact simpler. Which is why I don't get your #3 comment.

3- So ask every single person involved "is this issue clear or not" and I'll have...
- substantiation in the form of statistics??

I don't see how it matters if the connection is load side or supply side or the MDP is indoors or outdoors or even where the meter is.

With a supply side connection to a MDP in a potentially locked basement (I'd assume most people lock their houses when not home) with the meter also in the basement, inverter in garage with PV OCPD in garage...
just run some conductors into the house and pop a limiter on where they connect between meter and MDP?
Um...no! Does code prohibit that setup?

Even with a meter and supply side j-box outdoors, you can't put a limiter in the j-box and a plaque that says "INVERTER SWITCH MAY BE LOCKED IN GARAGE"...

 

[jaggedben]

It's honestly hard to make sense of your posts when taken all together.

I mean wow- if a house with a PV system happens to be on fire it could have *NOTHING* at all to do with the PV, but we run into the house to hit the MDP breaker to shut down the PV? Why

Indeed, why? If it's a load side connection then shutting down the service shuts down all AC power.

Basically all I'm trying to get across is that if you put a fused AC PV switch within 10 feet of an outdoor meter or service entrance, you are good to go.

What if I want to interconnect to a subpanel on the other side of the building?

2- I didn't say "more stringent", I said clearer and in fact simpler.

I'm calling your suggestion that the PV disconnect be required to be outside more stringent than the requirements for service disconnects.

3- So ask every single person involved "is this issue clear or not" and I'll have...
- substantiation in the form of statistics??

No. Real world examples count, not peoples opinions.

I don't see how it matters if the connection is load side or supply side or the MDP is indoors or outdoors or even where the meter is.

Really? One of them is shut down by the service and the other isn't. You don't think that emergency responders care if shutting down the power to a building requires throwing one switch or two?

 

[PVfarmer]

1 It's honestly hard to make sense of your posts when taken all together.
Indeed, why? If it's a load side connection then shutting down the service shuts down all AC power.

2 I'm calling your suggestion that the PV disconnect be required to be outside more stringent than the requirements for service disconnects.

3 Really? One of them is shut down by the service and the other isn't. You don't think that emergency responders care if shutting down the power to a building requires throwing one switch or two?

It's really weird, for some reason you keeping reading what I'm typing as the exact opposite of what I'm actually typing.

1 And the (main) service switch that shuts down the service could be locked inside the house with no PV switch outside. Not good.

2 Why are we arguing 2014 when the subject is 2017?
A meter outside with service MDP breaker directly inside without a PV system is *extremely* common, sure.
Splicing PV into those conductors between the meter and MDP service breaker with a PV switch elsewhere seems wrong. To me, and 2017 code apparently.

About opposite, 3 for instance. OF COURSE they care. That is my whole point. Why should they be forced to go inside when one or two switches outside is much safer?
A: 2 switches outside
B: 1 outside, 1 inside
C: 2 inside

In an emergency? I'll take A, thanks.

Hence this in 2017- it is in fact the "outside only" version of "readily accessible".



And this. The indoors option seems to be gone. Great!

 

[jaggedben]

I can't keep responding over and over to stuff that makes no logical sense. My final comments are 1) I don't agree that an indoor service or PV disconnect is a major saftey concern, and 2) you can't call for a modification to Art. 705 that addresses it and that makes any sense without also modifying Art. 230.

Try starting a thread in the non-PV section of the forum asking what poeple think of requiring the service disconnect to be outdoors, and see how that goes.

That's it, I'm done.

 

[PVfarmer]

Can anyone explain how the house breaker can be more than zero with the 200A PV breaker in this green interpretation?
On the supply side of...what?

To me 705.12 is saying- 100A PV OCPD + 100A house breaker = 200A service...
with a 200A PV OCPD and a 100A main service house breaker, 300A service is required.
200A PV OCPD + 200A house main load breaker = 400A service, max for resisdential.

When there is no 300A service offered that means 400A service for (200A PV OCPD = 160A actual PV output....160A + 100A house loads) ...how do the conductors ever see more than 160A?

Previously, the size limit for a supply side connection was not specified in the NEC. As of 2011, the Code takes a common sense approach, stating in Section 705.12(A) that the sum of the ratings of all overcurrent protection devices connected to the power production sources cannot be more than the rating of the service. For example, if the required inverter output circuit OCPD—which would typically be a fused disconnect sized per Sections 705.60 and 690.8—for a PV system is 200 amps, the existing AC service would have to be at least 200 amps in order to connect the PV system on the supply side.

2017-
705.12

1There is only one AHJ in Texas that I have dealt with so far who requires a N-G bond in the disco, and the NEC is ambiguous on the question.

I can't keep responding over and over to stuff that makes no logical sense. My final comments are

2) I don't agree that an indoor service or PV disconnect is a major saftey concern, and

3) you can't call for a modification to Art. 705 that addresses it and that makes any sense without also modifying Art. 230.

4 Try starting a thread in the non-PV section of the forum asking what poeple think of requiring the service disconnect to be outdoors, and see how that goes.

Not really expecting any responses here guys- we were having a few non-arguments for no apparent reasons.
This link (and its 2 example diagrams) and the "giant block of text" below address what we were not understanding each other about.

https://www.homepower.com/articles/...ng-supply-side-connection-article-705?v=print

1- That's a lot of net metering. The NEC is supply vs. load side, it has nothing to do with net metering and buy-sell all. The bond seems to.
2- Logic is that rapid shutdown switch = PV disco = outside.
3- See #2.
4- No. See #2 again.

More common in commercial applications is cutting into conduit or raceways between the meter and the main AC service disconnect to install an additional junction box inline. ... Be sure to verify that this will not violate the listing of the equipment (if the conductors are insulated bus bars then this likely will not be allowed) as they can’t be tapped and Polaris connectors cannot be used.

The requirements of NEC Article 230, “Services,” must be followed. A service-rated fused disconnect—the minimum size is 60 amps per Section 230.79(D)—is typically installed for supply side connections (using breakers can result in the panel needing to be oversized, for reasons that will be discussed in part 2 on load-side connections). The load side of the disconnect is connected to the PV system, and the line side to the utility. If the supply side connection is occurring between the main disconnect and the meter, then the new disconnect will count towards the maximum of six switches or breakers allowed per Section 230.71. However, Section 230.2(A) allows for additional services for parallel power production systems—the new meter and disconnecting means for a buy-all sell-all type interconnection should count as a separate service, but this will depend on the interpretation of the AHJ.

Section 230.91 dictates overcurrent protection device (OCPD) requirements, stating that the OCPD must either be integrated with or immediately adjacent to the disconnecting means. The current interrupting capability (AIC, not the “size”) of the fuses in the new disconnect must be sufficient to comply with Sections 110.9 and 110.10, typically meaning it must at least match the AIC rating of the existing AC service disconnect.

Some utilities may require a second, lockable disconnect near the point of interconnection. If required, it can be installed between the new, fused disconnect and the inverter, and thus overcurrent protection is not required in this additional “utility” disconnect. It can simply be a switch, ideally located immediately adjacent to the fused disconnect and labeled per utility requirements.

 

[Smart $]

Can anyone explain how the house breaker can be more than zero with the 200A PV breaker in this green interpretation?
On the supply side of...what?

To me 705.12 is saying- 100A PV OCPD + 100A house breaker = 200A service...
with a 200A PV OCPD and a 100A main service house breaker, 300A service is required.
200A PV OCPD + 200A house main load breaker = 400A service, max for resisdential.

When there is no 300A service offered that means 400A service for (200A PV OCPD = 160A actual PV output....160A + 100A house loads) ...how do the conductors ever see more than 160A?

Previously, the size limit for a supply side connection was not specified in the NEC. As of 2011, the Code takes a common sense approach, stating in Section 705.12(A) that the sum of the ratings of all overcurrent protection devices connected to the power production sources cannot be more than the rating of the service. For example, if the required inverter output circuit OCPD—which would typically be a fused disconnect sized per Sections 705.60 and 690.8—for a PV system is 200 amps, the existing AC service would have to be at least 200 amps in order to connect the PV system on the supply side.

Correct. Supply side connection OCPD can be up to the service rating.

 

[PVfarmer]

Correct. Supply side connection OCPD can be up to the service rating.

So 200A PV OCPD supply side + 200A MDP panel breaker = 200A service is ok?
The 200A MDP breaker being the "service disconnecting means".

(A) Supply Side. An electric power production source shall be permitted to be connected to the supply side of the service disconnecting means as permitted in 230.82(6). The sum of the ratings of all overcurrent devices connected to ___ power production sources shall not exceed the rating of the service.

Because the above could be read as including the MDP breaker- it is an overcurrent device, connected to 2 power production sources (PV/grid).

If (A) is supposed to say the green is ok, it would be a lot clearer if simply "PV" was inserted in the ___ area.

 

[jaggedben]

When it says power production sources that doesn't include the utility. See 705.2 definitions where it says 'other than a utility.'

Also remember that 705 covers other sources besides just PV.