Line side taps will be more difficult in 2026

[don_resqcapt19]

A First Revision change for the 2026 code will make it more difficult to make a line side tap for a solar system.

312.8(A) Splices, Taps, and Feed-Through Conductors.
The wiring space of enclosures for switches or overcurrent devices shall be permitted for conductors feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met:

1. The total of all conductors installed at any cross section of the wiring space does not exceed 40 percent of the cross-sectional area of that space.
2. The total area of all conductors, splices, and taps installed at any cross section of the wiring space does not exceed 75 percent of the cross-sectional area of that space.
3. The bending space for conductors 4 AWG and larger complies with 314.28(A)(2).
4. A warning label complying with 110.21(B) is applied to the enclosure that identifies the closest disconnecting means for any feed-through conductors.
5. The conductors are not service conductors.

 

[wwhitney]

Except the first sentence of the 312.8(A) is using the permissive "shall be permitted" language, and thus 312.8(A) is not imposing any prohibitions. Is there some other section that would prohibit splicing or tapping service conductors in an Article 312 cabinet?

Cheers, Wayne

 

[Elect117]

To me it sounds like you are not allowed to have service conductors feed through or have taps installed within any enclosure or meter socket. The only place left would be those covered by 314 right?

The first sentence throws me off. I was always under the impression 312.8 was for the space in the enclosure being enough for the conductor.

*** 2023 ***
312.8 -The wiring space within enclosures for switches and overcurrent devices shall be permitted for other wiring and equipment subject to limitations for specific equipment as provided in 312.8(A) and (B).

Where subsection A would provide allowances to impact the wiring space. The required condition to impact the wiring space would be all of (A)(1) through (A)(5).

Meaning, to me, that service conductors should not be feeding through, spliced or tapping off to other enclosures, switches or overcurrent devices.

My guess is that the intent is to remove the possibility of bringing service entrance conductors through an old service panel board to the new one, and then refeeding it since the AIC can change on the new service?


Did they provide any notes?

 

[don_resqcapt19]

Except the first sentence of the 312.8(A) is using the permissive "shall be permitted" language, and thus 312.8(A) is not imposing any prohibitions. Is there some other section that would prohibit splicing or tapping service conductors in an Article 312 cabinet?

Cheers, Wayne

"Shall be permitted "where all of the following conditions are met".

312.8(A) Splices, Taps, and Feed-Through Conductors.
The wiring space of enclosures for switches or overcurrent devices shall be permitted for conductors feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met:

The code change adds the condition that the conductors being spliced or tapped are not service conductors.

 

[wwhitney]

"Shall be permitted "where all of the following conditions are met".

Right which is not the same as "shall be permitted only where all the following conditions are met."

Back when "Conductors in Parallel" was 310.4 in the 2008 NEC and earlier it had this same language problem. In the 2011 NEC it was moved to 310.10(H) and they changed "shall be permitted" to "shall be permitted only" to change an allowance to a limitation.

Cheers, Wayne

 

[jaggedben]

If the enclosure that the conductors are passing through is service equipment I don't agree with this change. I agree with the clarification for non-service equipment enclosures.

 

[tortuga]

Ever since I discovered millbanks doubble lug adapters for their meters I have never looked back. No more splices or taps just two sets of service conductors leaving the meter.

 

[LarryFine]

Ever since I discovered millbanks doubble lug adapters for their meters I have never looked back. No more splices or taps just two sets of service conductors leaving the meter.
View attachment 2572549

I'll have to ask Dominion whether they are allowed here.

 

[don_resqcapt19]

Ever since I discovered millbanks doubble lug adapters for their meters I have never looked back. No more splices or taps just two sets of service conductors leaving the meter.
View attachment 2572549

Talked to a Milbank person at a trade show and he said, those are only permitted if the meter can itself has that item listed as an accessory.
In our area, it would not matter and the utility does not permit line side connections of any type in the meter can.

 

[don_resqcapt19]

Right which is not the same as "shall be permitted only where all the following conditions are met."

Back when "Conductors in Parallel" was 310.4 in the 2008 NEC and earlier it had this same language problem. In the 2011 NEC it was moved to 310.10(H) and they changed "shall be permitted" to "shall be permitted only" to change an allowance to a limitation.

Cheers, Wayne

Yes, I wrote the PI for the parallel conductors...took a couple of cycles to get the code changed. However, the parallel rule was enforced by most if not all AHJs prior to the language change, and the same thing applies here.

312.8 is a rule that actually worked better when it was an exception and not converted into positive text.

 

[tortuga]

the utility does not permit line side connections of any type in the meter can.

Then if you cant go from lugs to a disconnect how do you go from a meter to a main breaker? Wireless?
I've used those exact lugs to add a 60A service disconnect next to a 200A one for a well pump house, can't see why solar is any different.
I also called millabnk and they said they are for any millbank meter they fit.

 

[jaggedben]

...
In our area, it would not matter and the utility does not permit line side connections of any type in the meter can.

It's just an additonal set of service entrance conductors. Do they also not allow multiple sets of conductors to enter the meter for ordinary loads, or are they discriminating against certain things for no good reason?

 

[jaggedben]

Ever since I discovered millbanks doubble lug adapters for their meters I have never looked back. No more splices or taps just two sets of service conductors leaving the meter.
View attachment 2572549

Easy if you're setting up a new service, but still a lot more work than just pulling the meter and splicing the service conductors in the existing service panel.

 

[electrofelon]

It's just an additonal set of service entrance conductors. Do they also not allow multiple sets of conductors to enter the meter for ordinary loads, or are they discriminating against certain things for no good reason?

Yeah I have complained about this before, and it absolutely drives me crazy. If solar is involved it's somehow a "tap" I guess (like whatever that even means)

 

[electrofelon]

A First Revision change for the 2026 code will make it more difficult to make a line side tap for a solar system.

Did you look at the substantiation for this?

 

[don_resqcapt19]

It's just an additonal set of service entrance conductors. Do they also not allow multiple sets of conductors to enter the meter for ordinary loads, or are they discriminating against certain things for no good reason?

They only permit a single set of service conductors in the meter.

 

[don_resqcapt19]

Did you look at the substantiation for this?

I did, but the code text change is all that matters, not what the substantiation said.

 

[tortuga]

They only permit a single set of service conductors in the meter.

Do they not have class 320A meters in your area?

 

[don_resqcapt19]

Do they not have class 320A meters in your area?
View attachment 2572555

I guess they do permit that.