TC-ER Feeder for Residential

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GarwoodV6

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Houston suburbs
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30 year commercial Electrician
Cleaning up a Service and feeder on an existing home (built 1972) with 1/0 AL SE bare neutral, no ground feeding between floors to an existing 200A MLO panel located 25 feet across the attached garage from the original 200A Federal Pacific (!) Main breaker (Only) panel located inside garage behind 200A meter socket outside.

I can't believe triplex (bare neutral, no ground, open wire in attic and through joists between floors was used as a feeder inside the house, much less 1/0 which is only rated for 125A
Need to get rid of that F-P Main and upgrade the feeder to provide separate ground.

A whole-house generator installer pointed out code violations as well as signs of wire overheating on the existing service to the homeowner, and the owner wants to bring this up to current code for all the right reasons. Copper only, per the homeowner.
Putting an exterior MCB after the new Generator ATS and re-feeding the house with 4-wire feeder rated for 200 amps is the goal. the problem is the feeder route.

I need a Clarification:
Can TC-ER (marked JP) copper 2/0X3 with #6 ground cable be used as a 200A feeder without conduit inside the attic, between floors and down an interior wall?
It appears so, according to NEC 330.10 (9)
It also appears that it can be run on joists and through the wall top plate, secured every 4-1/2 feet etc. as in NM.

A crawl space alongside the 2nd floor will get me from the new outdoor 200A MB feed-through panel, but the panel is ~4-5 feet under the 2nd floor.
I can go around side of 2nd floor, chase the cable between 2nd floor joists from the crawl space and down into the interior wall where the existing home panel is now.
Crawl space access is very limited, and pipe run between floors would require a lot of demolition.
2/0 SER has a vastly oversized #1 ground, is unbelievably stiff, and is quite a bit more expensive than TC-ER "JP". I don't think I could man-handle the SER into place under these conditions. The TC-ER should be more manageable.
 
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I believe your reference would be to Art 336. Note that, as of the '17 Code, the TC-ER-JP is for cables with power & control and would not be applicable in your situation.
 
Yes- Article 336.10 (9)., not 330. My mistake (typo)
I appreciate your response... I did read that part about "and control", but took it to mean "if required for the application".

I wouldn't be considering the TC-ER if I could find a suitable cable with an appropriately sized ground that would be a bit easier to install in this circumstance. This is a tough retrofit installation. I did see a Code exception that would allow me to run a separate ground wire in this circumstance, but- the existing feeder is woefully undersized to begin with, and the bare neutral is a big concern, especially being open wiring path through the inside of a wood building

I question the wording of "and control"... is the control wiring really necessary to conform to the code provision, or is it simply allowing both in the same cable if needed i.e. for generators, split HVAC units, etc.?
The code DOES require the control cable conductors to be in its' own jacket inside the cable bundle to qualify. If it can carry the load with the control cable, why would it be wrong to use without the control conductors?
 
336.10(9)
In one- and two-family dwelling units, Type TC-ER cable
containing both power and control conductors that is
identified for pulling through structural members shall
be permitted. Type TC-ER cable used as interior wiring
shall be installed per the requirements of Part II of Article
334.
Click to expand...

I don't see how you can have both power and control conductors if there are only power conductors.
 
GarwoodV6 said:
Yes- Article 336.10 (9)., not 330. My mistake (typo)
I appreciate your response... I did read that part about "and control", but took it to mean "if required for the application".

I wouldn't be considering the TC-ER if I could find a suitable cable with an appropriately sized ground that would be a bit easier to install in this circumstance. This is a tough retrofit installation. I did see a Code exception that would allow me to run a separate ground wire in this circumstance, but- the existing feeder is woefully undersized to begin with, and the bare neutral is a big concern, especially being open wiring path through the inside of a wood building

I question the wording of "and control"... is the control wiring really necessary to conform to the code provision, or is it simply allowing both in the same cable if needed i.e. for generators, split HVAC units, etc.?
The code DOES require the control cable conductors to be in its' own jacket inside the cable bundle to qualify. If it can carry the load with the control cable, why would it be wrong to use without the control conductors?
Click to expand...
To be code compliant, the cable must have both power and control conductors, but there is no requirement that the control conductors actually be used.
This cable was originally produced for Generac and was put into the code by PIs from their people. It was intended to be used as generator feeder cable containing both the generator output power conductors and the control conductors between the ATS and the generator. However, the code has never actually limited the cable to that application, but it requires, no matter what application the cable is used for, that it contains control conductors.
Probably a good opportunity for a PI to make a change in the 2026 code.
 
jaggedben said:
SER cable is what you should use.
Click to expand...
The OP does mention and consider that option, but states it would be stiffer and therefore harder to use. At least partially because the bare conductor is oversized for EGC duty, but perhaps for other reasons of construction.

Would MC cable be a possibility? Not sure how it compares to SER and TC-ER-JP in terms of flexibility.

Cheers, Wayne
 
don_resqcapt19 said:
To be code compliant, the cable must have both power and control conductors, but there is no requirement that the control conductors actually be used.
This cable was originally produced for Generac and was put into the code by PIs from their people. It was intended to be used as generator feeder cable containing both the generator output power conductors and the control conductors between the ATS and the generator. However, the code has never actually limited the cable to that application, but it requires, no matter what application the cable is used for, that it contains control conductors.
Probably a good opportunity for a PI to make a change in the 2026 code.
Click to expand...
If there's nothing connected to a conductor how can it be a control conductor? It's only a control conductor if it's an article 725 conductor. It can't be an article 725 conductor unless it is in an article 725 circuit. Or whatever article they moved class one circuits to.
 
petersonra said:
If there's nothing connected to a conductor how can it be a control conductor? It's only a control conductor if it's an article 725 conductor. It can't be an article 725 conductor unless it is in an article 725 circuit. Or whatever article they moved class one circuits to.
Click to expand...
It is a physical presence in the cable that is required by the language in the code. It is a control conductor by size and requirements of the product standard. The standard for tray cable specifies that the power conductors are 14 AWG through 1000 kcmil.
 
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LarryFine said:
There is no reason for a main breaker after the ATS.
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Interesting... no Main D/S required after the ATS, even though the panel is 30 feet inside the house and the generator is 75 feet away on the opposite end of the house out of sight of the meter and ATS.
The ATS has no manual switch to disconnect the generator.
The generator cabinet has a red mushroom "Kill Switch" on the rear to stop the unit... according to the dealer that sold the system, that "kill switch" brings it into Code. The Fireman will have to go open the ATS, turn off the utility power CB, then go around the house to shut down the generator.
 
don_resqcapt19 said:
It is a physical presence in the cable that is required by the language in the code. It is a control conductor by size and requirements of the product standard. The standard for tray cable specifies that the power conductors are 14 AWG through 1000 kcmil.
Click to expand...
Where in the code does it say that an unconnected piece of wire is a conductor?
 
don_resqcapt19 said:
To be code compliant, the cable must have both power and control conductors, but there is no requirement that the control conductors actually be used.
This cable was originally produced for Generac and was put into the code by PIs from their people. It was intended to be used as generator feeder cable containing both the generator output power conductors and the control conductors between the ATS and the generator. However, the code has never actually limited the cable to that application, but it requires, no matter what application the cable is used for, that it contains control conductors.
Probably a good opportunity for a PI to make a change in the 2026 code.
Click to expand...
That's what struck me... If I have control wiring but it is not used, TC-ER with JP (Joist Pull) marking would comply with NEC to use as a standard feeder cable -BUT- NOT if it lacks the control cable inside the jacket with the Current Carrying Conductors?
The presence or absence of a control cable inside the outer jacket has no effect on the TC-ER functioning as a feeder or its suitability in this installation.

The "and" wording in the 2020 NEC suggest that the presence of the control cable itself within the TC-ER cable can be included or excluded.
 
petersonra said:
Where in the code does it say that an unconnected piece of wire is a conductor?
Click to expand...
How it is not a conductor? Conductor is anything that can carry current....says nothing about requiring it to carry current. None of the 3 definitions that cover conductors in Article 100 says anything about then carrying current or being connected to a circuit.
 
GarwoodV6 said:
Interesting... no Main D/S required after the ATS, even though the panel is 30 feet inside the house and the generator is 75 feet away on the opposite end of the house out of sight of the meter and ATS.
Click to expand...
Yes, within the same structure, the outside OCP/disconnect is all that is needed, and a main-lug panel.

The ATS has no manual switch to disconnect the generator.
Click to expand...
Then put a disco between the generator and the ATS, which would only need to be sized for its output capacity.

The generator cabinet has a red mushroom "Kill Switch" on the rear to stop the unit... according to the dealer that sold the system, that "kill switch" brings it into Code. The Fireman will have to go open the ATS, turn off the utility power CB, then go around the house to shut down the generator.
Click to expand...
Then put a disco between the generator and the ATS at the ATS, which would effectively group them.


My point is that you don't need a 200a disconnect; only one large enough for the generator.

The ATS should be service rated or have a service disco ahead of it.
 
don_resqcapt19 said:
How it is not a conductor? Conductor is anything that can carry current....says nothing about requiring it to carry current. None of the 3 definitions that cover conductors in Article 100 says anything about then carrying current or being connected to a circuit.
Click to expand...
Conductor, Bare. A conductor having no covering or electrical
insulation whatsoever. (CMP-6)
Conductor, Covered. A conductor encased within material of
composition or thickness that is not recognized by this Code as
electrical insulation. (CMP-6)
Conductor, Insulated. A conductor encased within material of
composition and thickness that is recognized by this Code as
electrical insulation. (CMP-6)
Click to expand...

The three definitions are pretty circular. So, they don't define what a conductor is. Oddly, there does not seem to be a definition of conductor in the code.
 
petersonra said:
The three definitions are pretty circular. So, they don't define what a conductor is. Oddly, there does not seem to be a definition of conductor in the code.
Click to expand...
Not really odd...The scope of Article 100 says "...It is not intended to include commonly defined general terms...". This is commonly defined general term.

The NFPA glossary of terms defines it as "A material or object that allows an electric charge to flow easily through it."

I can't remember what dictionary is specified by the NFPA for common terms used in the NEC, but I expect that no matter what dictionary you pick, the definition will be based on the physical properties of the material, and not not function.
 
LarryFine said:
Yes, within the same structure, the outside OCP/disconnect is all that is needed, and a main-lug panel.


Then put a disco between the generator and the ATS, which would only need to be sized for its output capacity.


Then put a disco between the generator and the ATS at the ATS, which would effectively group them.


My point is that you don't need a 200a disconnect; only one large enough for the generator.

The ATS should be service rated or have a service disco ahead of it.
Click to expand...
The ATS IS Service Rated. It has two thumbscrews holding the WP cover in place.
The Generator feeder is already installed, SER run through the attic into a conduit down into the ATS.
A 200A Feed-through Panel installed after the ATS is the most cost-effective means of D/S available (~$200 in materials)
 
LarryFine said:
Yes, within the same structure, the outside OCP/disconnect is all that is needed, and a main-lug panel.


Then put a disco between the generator and the ATS, which would only need to be sized for its output capacity.


Then put a disco between the generator and the ATS at the ATS, which would effectively group them.


My point is that you don't need a 200a disconnect; only one large enough for the generator.

The ATS should be service rated or have a service disco ahead of it.
Click to expand...
Does NEC 2020 permit the Generator D/S or shutdown to be located elsewhere (halfway around the house, 75 feet away in this case)?
Or must they be grouped, or "within sight and less than (x) feet" from the Service &/or ATS?
 
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