tap location question

Status
Not open for further replies.
I was about to perform a tap in a 200 amp main panel in the homeowner's garage I was planning on putting my disconnect back to back from the main panel outside the homeowner's garage with a 3 inch nipple My boss showed up and quickly informed me that I could not do that because they disconnect would have to be below the main panel where I'm tApping I did not see an issue with it because I am within my 10 feet pv system size is a 10K with two 5K inverters that are being Placed outside garage wall Disconnect size 60 amp fuse disconnect with 60 amp fuses If something Could guide me in the right direction to why he said this to me if it is even true I'm a little confused
 

Carultch

Senior Member
Location
Massachusetts
I was about to perform a tap in a 200 amp main panel in the homeowner's garage I was planning on putting my disconnect back to back from the main panel outside the homeowner's garage with a 3 inch nipple My boss showed up and quickly informed me that I could not do that because they disconnect would have to be below the main panel where I'm tApping I did not see an issue with it because I am within my 10 feet pv system size is a 10K with two 5K inverters that are being Placed outside garage wall Disconnect size 60 amp fuse disconnect with 60 amp fuses If something Could guide me in the right direction to why he said this to me if it is even true I'm a little confused

I've done the same thing before, and had it approved. I'm not seeing the specific NEC rule that would prohibit this, unless it is a utility or local rule. Utilities often do require an outside switch, and using one disconnect for multiple purposes is something we all try to do.

The one thing you do want to avoid doing, is mixing permanently energized conductors (service conductors, tap conductors) with load-side conductors. So this means, don't count on sharing the nipple with the conductors to and from the disconnect. Dedicate it to the tap conductors only.

At most, I could see it as an interpretation of how the "10 feet" is supposed to be measured. Is it 10 ft of wire length? 10 ft of walkable distance? 10 ft of visual distance? Or 10 ft of absolute distance? The fact that it isn't specified means that by omission, it is not incorrect to locate it within 10 ft of absolute distance, even if the wall is a barrier or if you take a 25 foot serpentine path to wire it.
 

Smart $

Esteemed Member
Location
Ohio
If this is a line side connection, there are those that believe the PV System Disconnect is also a Service Disconnecting Means and therefore must comply with 230.72 grouping of two to six disconnecting means.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
If this is a line side connection, there are those that believe the PV System Disconnect is also a Service Disconnecting Means and therefore must comply with 230.72 grouping of two to six disconnecting means.
There are those of us who don't, and then there's guys like me who are agnostic on the subject and just do it the way the AHJ says to.
 
If this is a line side connection, there are those that believe the PV System Disconnect is also a Service Disconnecting Means and therefore must comply with 230.72 grouping of two to six disconnecting means.

I think those two things are mutually exclusive, that is it could still be a service disconnect but not require grouping with the "normal" service disconnects. That is the way I see the language.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
230.71(A) says that the disconnects must be grouped for each service 'or for each set of service entrance conductors permitted by 230.40'. I read this as allowing the PV to be grouped separately if you are installing new service conductors.

Good luck getting your AHJ to agree with my reading though.
 
230.71(A) says that the disconnects must be grouped for each service 'or for each set of service entrance conductors permitted by 230.40'. I read this as allowing the PV to be grouped separately if you are installing new service conductors.

Good luck getting your AHJ to agree with my reading though.

That is the way I see it as well. I dont really see how it could be reasonably interpreted any other way. All the other exceptions to 230.40 mentioned by 230.71 (1,3,4 or whatever - going from memory) are all situations where the disconnects will not be grouped, so why would #5 be different?
 

Smart $

Esteemed Member
Location
Ohio
I think those two things are mutually exclusive, that is it could still be a service disconnect but not require grouping with the "normal" service disconnects. That is the way I see the language.
Technically, notwithstanding NEC jargon, a PV System is an alternate power source... similar to connecting a synchronized generator system.

A service disconnecting means implies the utility is supplying power to utilization equipment on the load side of the disconnect. A PV system does not qualify as utilization equipment, and if there is a load side to the disconnect, it is the utility side. So a PV System Disconnect cannot be a Service Disconnecting Means.
 
A service disconnecting means implies the utility is supplying power to utilization equipment on the load side of the disconnect. A PV system does not qualify as utilization equipment, and if there is a load side to the disconnect, it is the utility side. So a PV System Disconnect cannot be a Service Disconnecting Means.

I really dont agree with that at all for two main reasons. First there is a lot of stuff in there with no NEC basis. Secondly, I have never ever seen line and load on things like meters and disconnects "reversed" for solar systems.
 

Smart $

Esteemed Member
Location
Ohio
I really dont agree with that at all for two main reasons. First there is a lot of stuff in there with no NEC basis. Secondly, I have never ever seen line and load on things like meters and disconnects "reversed" for solar systems.
There is no line and load when we are talking just power sources. Yet there will have to be a load somewhere in the system, or there'd be no point of having the power sources to begin with. What we are really talking about here is how the power sources are interconnected and where the loads are with respect to that interconnection. Are the sources directly connected with the load branched off, or is the load in between, or a combination thereof? In this case, we are talking about the load being off to a side and the power sources directly connected. Now look up the definition of Service in Article 100. Such a disconnect cannot be a Service Disconnecting Means... by definition.
 

iwire

Moderator
Staff member
Location
Massachusetts
I really dont agree with that at all for two main reasons. First there is a lot of stuff in there with no NEC basis. Secondly, I have never ever seen line and load on things like meters and disconnects "reversed" for solar systems.

How can you not agree with facts?:?
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
I really dont agree with that at all for two main reasons. First there is a lot of stuff in there with no NEC basis. Secondly, I have never ever seen line and load on things like meters and disconnects "reversed" for solar systems.
Maybe I am misunderstanding you but we do it all the time. A PV system feeds the load side of a fused AC disconnect. What is "load" and line" with respect to current flow depends on whether you are talking about normal operation or a fault condition.
 

Carultch

Senior Member
Location
Massachusetts
Maybe I am misunderstanding you but we do it all the time. A PV system feeds the load side of a fused AC disconnect. What is "load" and line" with respect to current flow depends on whether you are talking about normal operation or a fault condition.

In this case, the "line" and "load" markings indicate which side is connected to the permanently energized source (line for utility side), and which is connected to the source that will deenergize in the open position (load for PV side).

The reason is such that if there is a plastic cover on the line side (common on 600V units), it prevents unintentional contact with energized terminals. And if there are fuses, they are then on the side that is de-energized by the open blades.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
In this case, the "line" and "load" markings indicate which side is connected to the permanently energized source (line for utility side), and which is connected to the source that will deenergize in the open position (load for PV side).

The reason is such that if there is a plastic cover on the line side (common on 600V units), it prevents unintentional contact with energized terminals. And if there are fuses, they are then on the side that is de-energized by the open blades.

Of course. I had an electrician argue with me about that once. I told him that he could change the fuses in that disco but I wasn't touching them. :D
 
Maybe I am misunderstanding you but we do it all the time. A PV system feeds the load side of a fused AC disconnect. What is "load" and line" with respect to current flow depends on whether you are talking about normal operation or a fault condition.

Correct and I agree. When I first read Smart$'s statement:
and if there is a load side to the disconnect, it is the utility side.

I thought he was saying otherwise, however I now realize that was part of a 'proof by contradiction'

How can you not agree with facts?

If it was so clear cut, this PV disconnect issue wouldn't be debated all the time :roll:

Now look up the definition of Service in Article 100. Such a disconnect cannot be a Service Disconnecting Means... by definition.

I can see your argument, but I dont think that is the intent and the definition needs revision. Consider the service conductors on the utility side of the PV tap point. Does this whole thing become not a service whenever the PV is making more energy then is being used? IT all seems quite convoluted and a stretch to me

VERSUS

230.40 Ex 5 allows us to make another set of service entrance conductors. Look at the definition of service entrance conductors....

I am not saying there is nothing in the code that points to your position, but considering the NEC is written by humans and with a preponderance of evidence, IMO, it being a service disconnect is more robust position.
 

Carultch

Senior Member
Location
Massachusetts
If it was so clear cut, this PV disconnect issue wouldn't be debated all the time :roll:

I feel like 705.12(A) is the place where all the specifics of this issue should be answered. Such as, is or isn't it a "service disconnect", and should or should not ground and neutral be bonded at it?
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
2011 NEC Definitions said:
Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.
So does this mean that conductors and equipment that only ever carry electric energy from the PV system to the serving utility (line side connection) are not a service?

Cheers, Wayne
 

Carultch

Senior Member
Location
Massachusetts
So does this mean that conductors and equipment that only ever carry electric energy from the PV system to the serving utility (line side connection) are not a service?

Cheers, Wayne

They are conductors in uncharted nomenclature territory, where we don't really know what to call them. They sort of function as service conductors, and they sort of function as tap conductors.
 
They are conductors in uncharted nomenclature territory, where we don't really know what to call them. They sort of function as service conductors, and they sort of function as tap conductors.

they are service entrance conductors plain and simple. My opinion, as I have mentioned before, is they should get rid of the whole "supply side connection" nonsense. The wording is basically all there, just needs a few tweaks.
 
Status
Not open for further replies.
Top