Heat trace Cable Extensions

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Ambient44

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We recently were bought onto a Chemical plant to bid on installing heat trace cable, the plant has a lot of existing 120 & 277V heat trace already installed on chemical lines, mostly caustic 4"to 6" lines that need to be 80-90F maintained. (Caustic hardens at 50F). They are re-doing a section of pipe for the caustic tanks and asked us to quote re-installing the heat trace once the pipework is done. Upon investigation of the existing installation, it was determined the previous contractor ran a non-heat trace 2-conductor cable along the existing pipe that was heat traced to extend the 120v circuit to another area of the pipe that needed a new heat trace line installed.

I have never seen this installation method for heat trace and was wondering if anyone know if this was in violation of the code?

It seems it is a lot more reasonable then running PVC coated GRC conduit to a splice box. (Caustic is highly corrosive).

Thank you for your input
 
Ambient44 said:
We recently were bought onto a Chemical plant to bid on installing heat trace cable, the plant has a lot of existing 120 & 277V heat trace already installed on chemical lines, mostly caustic 4"to 6" lines that need to be 80-90F maintained. (Caustic hardens at 50F). They are re-doing a section of pipe for the caustic tanks and asked us to quote re-installing the heat trace once the pipework is done. Upon investigation of the existing installation, it was determined the previous contractor ran a non-heat trace 2-conductor cable along the existing pipe that was heat traced to extend the 120v circuit to another area of the pipe that needed a new heat trace line installed.

I have never seen this installation method for heat trace and was wondering if anyone know if this was in violation of the code?

It seems it is a lot more reasonable then running PVC coated GRC conduit to a splice box. (Caustic is highly corrosive).

Thank you for your input
Click to expand...
IMHO Its a violation of 110.3B.
 
Can you provide a better description of the cable ? (metal clad, thermoplastic insulated, cord, etc)
 
Looks like a 12/3 triplex flat cable, I found a boat cable that looks like it:
www.solidsignal.com

Ancor 100ft Triplex Marine Grade Cable 12/3 AWG (131310)

Triplex Cable - 12/3 AWG - 100', Ancor Triplex Cable is made to surpass the highest UL Boat Cable standards with ultra flexible (Type 3/Class... Learn More!
www.solidsignal.com www.solidsignal.com
, except the outer jacket was black and not white. The markings were worn off the cable so I cannot get a specification off the wire.
The previous contractor did come up out of the insulation into a FS box with sealed gland fitting to splice to the heat trace and everything was grounded.

The reference to 110.3B is too general of a guideline in this circumstance to me. Unless cable has a listing or a labeling of use which designated the cable cannot be used in this fashion. If left up to the judgment of the AHJ I feel it would be rejected just because it is not according to industry standards, especially if they have no safety violations or codes, they can justify their position with. I'm not arguing here just been down that road too many times in my 35 years in this industry where inspectors make declarations with no evidence or justification for doing so. Just because I said so....
As a contractor I would use the Rob-Roy anyway because we would make more profit off the installation, and I know it would be done right. I just would like to see if there is a code violation someone knows of somewhere so I can present it to the customer. I cannot find one.

I personally do not see anything dangerous about the installation method if the cable falls into all the temperature ratings, grounding, overcurrent and GFCI protections according to the code or wire specifications. There is just as much voltage flowing through the heat trace cable as there is through the power cable and the protection is the same.
 
Without knowing the specificcable it would be difficult to cite a specific Code violation. The most likely one would be 400.12(1) and the concern is normally physical damage and deterioration over time.
 
I seem to recall seeing similar installations. I think the heat trace people had some kind of extension cable you could add to the end of a heat trace cable to connect to another segment of heat trace cable. Not sure if my memory is accurate or not though.
 
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