Supply side taps and panel listings

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Ctay005

Member
Location
Orem, Utah, USA
I've recently just had my 2nd AHJ mention the panel listing when looking over a supply side connection 1-line. His comment was, "Show in detail how the supply side connection will not violate the panel listing" Does the panels label specifically need to state that it is okay to connect to the line side or what is he looking for?
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I've recently just had my 2nd AHJ mention the panel listing when looking over a supply side connection 1-line. His comment was, "Show in detail how the supply side connection will not violate the panel listing" Does the panels label specifically need to state that it is okay to connect to the line side or what is he looking for?
He could be asking about a situation where your supply side connection is made by double lugging the input terminals of the panel (often not permissible.)
Or using feed through terminals on the panel for your supply side connection.
If the supply side connection is made to the service conductors before they terminate on the panel, then there is nothing which would affect the panel listing in any way.
(i.e. I do not think it would be a violation of the listing of a 100A panel to connect it directly to a 200A POCO service, as long as the connection was made through a 100A main breaker on the panel.

There could be some esoteric calculations involving SCCR, AIC and available fault current, but if he is concerned about that he should be more specific.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Can you provide the details as to what supply side connections you are making.
 

Ctay005

Member
Location
Orem, Utah, USA
Can you provide the details as to what supply side connections you are making.

I'm going to be installing a SolarEdge 5000W inverter on a house with a 100A/100A service. (Need 30A OCPD for the connection) The connection will be made to the service conductors and everything will be sized according to the 2013 CEC as required by the local authorities.

Again the AHJ was so vague in his request that I'm not sure what he was asking for and his turnaround time for questions is about a week.
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I'll let someone more versed in Art 690 address the install from that standpoint. Otherwise I would be concerned as to the lug being rated to accept those two conductors.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I think it comes down to whether the main breaker and/or the conductors between the meter and the main breaker are factory installed and thus part of the listed assembly.

For example, if you have a meter/main combo and the conductors between the meter and the main breaker are busbars, or factory installed conductors or some such, you could well be violating the listing if you mess with them. You would generally need to have a separate meter and main panel, or else create that situation if you don't have it (say, but putting a new meter socket and j-box ahead of the existing meter/main).

I would try to give the AHJ something along the lines of:

"The existing conductors between the meter and the main breaker were field installed. These conductors will be tapped with [such and such hardware listed for the purpose.] The installation will comply with [such and such code articles that require space for splicing conductors inside enclosures, etc. etc.]. Etc. Etc."
 

kwired

Electron manager
Location
NE Nebraska
I'm going to be installing a SolarEdge 5000W inverter on a house with a 100A/100A service. (Need 30A OCPD for the connection) The connection will be made to the service conductors and everything will be sized according to the 2013 CEC as required by the local authorities.

Again the AHJ was so vague in his request that I'm not sure what he was asking for and his turnaround time for questions is about a week.

I've recently just had my 2nd AHJ mention the panel listing when looking over a supply side connection 1-line. His comment was, "Show in detail how the supply side connection will not violate the panel listing" Does the panels label specifically need to state that it is okay to connect to the line side or what is he looking for?

More detail is needed from you and or the AHJ. If you are tapping the "conductor" and not adding a additional termination method to the equipment I don't see how any panel listing is even impacted. If that is the case he should only be questioning the conductor size or maybe if there is sufficient space at the location to make the tap.
 

Ctay005

Member
Location
Orem, Utah, USA
I'm going to be tapping the conductors before they terminate at the busbars in the panel.

I got a phonecall with the AHJ today so hopefully I'll figure out what he is looking for.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
I'm going to be tapping the conductors before they terminate at the busbars in the panel.

I got a phonecall with the AHJ today so hopefully I'll figure out what he is looking for.
The busbar rating should be a non-issue, but the conductors you will be tapping are subject to the 120% rule.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
The busbar rating should be a non-issue, but the conductors you will be tapping are subject to the 120% rule.

That's not correct for a supply side connection. (However if the conductors terminate at busbars, as he stated, rather than at a main breaker, that could call into question whether this is a supply side connection of not.)
 

Zee

Senior Member
Location
CA
More detail is needed from you and or the AHJ. If you are tapping the "conductor" and not adding a additional termination method to the equipment I don't see how any panel listing is even impacted.

But the conductors form the meter to the main would be part of the listed panel assembly if it is a combination meter/main panel, right? In fact, these are often bars.

In California these combo panels are the norm.
 

kwired

Electron manager
Location
NE Nebraska
But the conductors form the meter to the main would be part of the listed panel assembly if it is a combination meter/main panel, right? In fact, these are often bars.

In California these combo panels are the norm.
Correct, I was referring to field installed conductors being separate from the listed equipment and what you do with them has little to do with the listing of the equipment.
 

Zee

Senior Member
Location
CA
Correct, I was referring to field installed conductors being separate from the listed equipment and what you do with them has little to do with the listing of the equipment.
Yes, I agree. Hopefully he can tap the wire itself and not land in the terminals.
 
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Ctay005

Member
Location
Orem, Utah, USA
Yes, I agree. Hopefully he can tap the wire itself and not land in the terminals.


Just talked to the inspector. He thought from my drawings that we were double lugging. I cleared it up and told him we are tapping into the wires and sent him pictures of the panel showing the wires that we will be tapping into and he OK'd the plans.
 
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