Line side taps will be more difficult in 2026

don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
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.
Click to expand...
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
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
 
E

Elect117

Senior Member
Location
California
Occupation
Engineer E.E. P.E.
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

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
wwhitney said:
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
Click to expand...
"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:
Click to expand...

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

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
don_resqcapt19 said:
"Shall be permitted "where all of the following conditions are met".
Click to expand...
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
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
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.
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
tortuga said:
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
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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

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
wwhitney said:
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
Click to expand...
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

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
don_resqcapt19 said:
the utility does not permit line side connections of any type in the meter can.
Click to expand...
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.
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
don_resqcapt19 said:
...
In our area, it would not matter and the utility does not permit line side connections of any type in the meter can.
Click to expand...
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?
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
jaggedben said:
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?
Click to expand...
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)🙄
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
jaggedben said:
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?
Click to expand...
They only permit a single set of service conductors in the meter.
 
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