Pipeline heating cable protected with GFCI

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smallfish

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Section 427.22, 2005NEC requires ground-fault protection of equipment (GFPE) for electric heat tracing (heating cables for water-line freeze protection). Is it code permissible to use ground-fault circuit interruption protection (GFCI) instead? If not, why not?
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Yes you can use a GFCI as that will provide ground fault protection, the down side is it might trip when there is no need for it to.
 
GFCI has a lower trip threshold, so it would work, but would it be listed for that use? The lawyers today can make a case against anything, no matter how ridiculus!
 
The residential style heat cable systems use an in line GFCI. Mobile homes are required to have a gfci receptacle underneath for heat cable.
The listing question brought up above is interesting, I'd have to check UL.
 
GFCI vs. GFPE.
One interrupts the circuit in case of a ground fault. The other protects equipment in case of a ground fault. IMHO two different animals, I'm not too familiar with GFPE...This raises a good question. And the GFCI which you referenced as ground fault circuit interruption "protection" does not really guarantee a protection on the equipment. Or does it? If the equipment is on the load side of a GFCI circuit, can we say the equipment is GFCI protected? That is the question.
 
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Kdawg67 said:
GFCI vs. GFPE.
One interrupts the circuit in case of a ground fault. The other protects equipment in case of a ground fault. IMHO two different animals, I'm not too familiar with GFPE...This raises a good question. And the GFCI which you referenced as ground fault circuit interruption "protection" does not really guarantee a protection on the equipment. Or does it? If the equipment is on the load side of a GFCI circuit, can we say the equipment is GFCI protected? That is the question.
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The difference between the two is only the level of ground fault current before they interrupt the circuit. A GFCI opens the circuit at ~5mA and GFPE opens the circuit ~20 to 30mA. The GFPE rules come from a number of house trailer fires that were caused by heat tape ground faults. With a trip point of 20 to 30 mA there should not be enough energy to cause a fire. They don't really protect the heat tape itself as the leakage current only gets to the trip point if the heat tape has been damaged or has failed.
 
Kdawg67 said:
O.K... Thank you for the clarification. But, I've got to think heat tape isn't the only thing that would require GFPE.
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You are right there, some feeders and services require GFP, the trip level will be different in each installation and chosen low enough to protect the equipment and hopefully high enough a branch circuit ground fault goes not dump an entire feeder or service.
 
Arc fault breakers supposedly have close to the same setting as the GFPE, but then again there's that listing problem again. I personally think that they would work even better due to the combination arc fault sensing technology. If the heat tape is on a non conductive pipe, with non-conductive flammable styrofoam insulation around it, ground fault protection would be useless if the heat tape failed, as no current leakage to ground could be possible if conditions are right.
 
hillbilly1 said:
Arc fault breakers supposedly have close to the same setting as the GFPE, but then again there's that listing problem again. I personally think that they would work even better due to the combination arc fault sensing technology. If the heat tape is on a non conductive pipe, with non-conductive flammable styrofoam insulation around it, ground fault protection would be useless if the heat tape failed, as no current leakage to ground could be possible if conditions are right.
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How would there not be leakage to ground...the heat tape is require to have an outer conductive sheath that is connected to the EGC. See 427.23, however I am not sure if that rule applied to the premade heat trace with a plug. That type is required to be listed per 422.50 and part of the UL white book information says "Unless specifically indicated otherwise by marking on the heating cable or in the installation instructions, this heating cable is intended for use only on metallic pipes." It would be my guess that heat cables marked for use on nonmetallic pipes would have the conductive outer sheath. On a metallic pipe, the pipe would provide the ground fault path.
 
hillbilly1 said:
If the heat tape is on a non conductive pipe, with non-conductive flammable styrofoam insulation around it, ground fault protection would be useless if the heat tape failed, as no current leakage to ground could be possible if conditions are right.[/quote]



How about the cable itself is installed in contact with the metallic pipe, which is most likely bonded to ground itself....
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Pierre C Belarge said:
hillbilly1 said:
If the heat tape is on a non conductive pipe, with non-conductive flammable styrofoam insulation around it, ground fault protection would be useless if the heat tape failed, as no current leakage to ground could be possible if conditions are right.[/quote]



How about the cable itself is installed in contact with the metallic pipe, which is most likely bonded to ground itself....
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Re-read my post, I stated NON CONDUCTIVE PIPE, Heat tapes are also used on pvc, cpvc and black poly also.
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iwire said:
I agree heat trace gets used on those products but I bet the unshielded trace tape is not listed for the use.
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Good point, I did a search and did find some non-shielded trace tape that manufacture said it could be used for plastic pipe. Whether it is UL listed for this, it did not say.
 
hillbilly1 said:
Good point, I did a search and did find some non-shielded trace tape that manufacture said it could be used for plastic pipe. Whether it is UL listed for this, it did not say.
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First unless this is a heat tape with a manufacturer installed cord end the code rule in 427.23 requires a conductive outer covering. Second, I don't think UL lists a manufactured heat tape for non-metallic piping that does not have an outer conductive covering.
 
don_resqcapt19 said:
First unless this is a heat tape with a manufacturer installed cord end the code rule in 427.23 requires a conductive outer covering. Second, I don't think UL lists a manufactured heat tape for non-metallic piping that does not have an outer conductive covering.
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I have seen many heat tapes that do not have the conductive covering, and yes they were factory assemblies, but it still does not negate the requirement for GFEP for pipes. I just looked up one manufacture that recommended wrapping the plastic pipe with foil, there heat tape was not UL listed. The conductive covering is probably a newer requirement ( At least in the past 10 years, It takes a while for everybody to get on board).
 
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