Ok guys and gals, here's another question and this time I won't bring up the green screw issue
If we are installing or inspecting a heat tape as described in Article 422 Section 422..50. Must it comply with Article 427 Section 427.22? And if so, would you accept or install GFCI protection as an alternate?

I think that 427.22 applies and that a GFCI provides more protection that what is required by the code so it should be permitted. However, if the length is long, the normal leakage current from the heat tape may cause the GFCI to trip. Remember that the nominal trip point of a GFCI is 1/6 of the trip point of the GFP protection required by the code.
Don

I think GFCI protection is not permitted because the article specifically calls for GFPE. From a practical perspective, a GFCI protected circuit would have nusiance tripping and would soon be replaced with only standard overload protection. GFPE is available in 30 or 50ma trip level and only in the breaker version. Cost of GFPE about $100 and cost of GFCI a fraction of that.

George,
Have you made installations using GFCI and had problems? I don't see a nusiance tripping as a problem in a normal dwelling unit application because the heat trace length is too short. I also don't see that as a violation. The Consumer Product Safety Commission recommends the use of GFCI protection for heat tapes and in a mobile home 550.13(E) requires the heat trace receptacle to have GFCI protection.
Don


[This message has been edited by resqcapt19 (edited 05-24-2004).]

Don- I have bee an inspector for 20 years and even when I wore the tools, I don't recall there being a need for GFPE or GFCI for heat tapes. I installed so few of them that I don't remember having a problem at all. Read your CPSC reference- Thank You- My comment would be that the CPSC is not up to speed with the current code on heat tracing. As to the Mobile Home setting, we are not sent to Article 427 for protection but instead ask for GFCI. This type of thing makes me crazy. GFPE is equipment protection and GFCI is people protection. I know you are aware of that and maybe 427 was intended for other than mobile homes. I do think that in other than moblle homes, Article 427.22 applies. Hope we get other comments.

That is the part of the CPSC statement that I was thinking about.
The first GFP requirement was in the '87 code and only applied to heat tape that did not have a metal covering. The proposal called for GFCI, but was revised to GFP at the comment stage. The reason for the change was that on long industrial type installations that the normal leakage current would often exceed the 5mA trip point of a GFCI. In the 96 code the GFP requirement was expanded to cover all heat tape, even that with a metllic covering. This was based fires that were started by heat trace, even with a metallic jacket, when protected by standard breakers. 96 was also the year that 550 required GFCI protection for the mobile home heat trace receptacle. One of the substantiations said that 60% of the heat tape related fires occur in mobile homes. There were comments that recommended GFP in place of GFCI, but they were rejected. This same issue (GFP vs GFCI) was addressed again in the 99 code cycle with CMP 19 requiring the continued use of GFCI protection. The panel statement said in part "the panel's intent is to provide protection for personnel".

Don

Thanks Don.

One final thought- We are talking about heat tracing on pipes with a cord and cap connection and when we move to snow and Ice melting equipment as in roof tapes, we are back to GFPE if I;m not mistaken.

George,


I hope you do too, this is an interesting question you raised.

I was thinking that as the requirement is for GFP we had an option of using GFP or GFCI.

Now I am not as sure, for ice melting equipment.

We are required to provide OCP that is adequate for the load so why wouldn't we be required to provide ground fault protection that is adequate for the load?

I know we use some type of GF for protection for all of this equipment and many times it is GFCI type for small sections of heat trace, it seems to work fine.

The larger jobs we use GFP breakers.


Bob

After doing some research and thanks to Don we have the CPSC suggestion, I find that based on 426.28 the mandatory word "shall" pops up and it looks like we will need GFPE for snow melting equipment. And back to heat tracing, I'll allow GFCI protection for heat tapes as used on mobile homes but that's it. I mean, where's the CPSC when you are in court defending the NEC?

This information was found in the UL Directory and should be reviewed. I believe this applies:

EQUIPMENT GROUND-FAULT
PROTECTIVE DEVICES (FTTE)
This category covers Equipment Ground-Fault Protective Devices
(EGFPD) which operate to disconnect the electric circuit from the source
of supply when ground-fault current exceeds the ground-fault pick-up
level marked on the device.
To aid the user in making proper selection of this equipment, the EGFPDs
are marked with a ground-fault pick-up level in milliamperes and
with a voltage and current rating. The ground-fault pick-up level is limited
to the range above 6 mA to 50 mA. These devices are intended to
operate upon a condition of excessive ground-fault leakage current from
equipment, rather than minimize damage due to arcing faults in services.
EGFPDs are intended to be installed only on grounded alternating current
systems in accordance with the National Electrical Code ANSI/
NFPA-70.
EGFPDs are intended for use in applications where ground-fault protection
of equipment is required by the National Electrical Code, specifically
Sections 426-28 and 427-22, or where such protection is deemed appropriate.
A two-wire device is not suitable for use in a multiwire branch circuit as
defined in the National Electrical Code.
The devices covered by this category have not been evaluated to provide
electric shock protection for personnel and they are not intended to be
used in place of a ground-fault circuit interrupter (GFCI) where a GFCI is
required by the National Electrical Code. See Ground-Fault Circuit Interrupters
(KCXS) for further information.
The devices covered by this category are not intended to be used in electrical
service entrance equipment where ground-fault sensing and relaying
equipment, required by Section 230-95 of the National Electrical Code, is
used. See Ground-Fault Sensing and Relaying Equipment (KDAX) for further
information.
The basic standard used to investigate products in this category is UL
1053, ‘‘Ground-Fault Sensing and Relaying Equipment.’’ Some requirements
are also derived from UL 943, ‘‘Ground-Fault Circuit-Interrupters.’’
The Listing Mark of Underwriters Laboratories Inc. on the product is the
only method provided by UL to identify products manufactured under its
Listing and Follow-Up Service. The Listing Mark for these products
includes the UL symbol (as illustrated in the Introduction of this Directory)
together with the word ‘‘LISTED,’’ a control number, and the product
name ‘‘Equipment Ground-Fault Protective Device’’ or ‘‘EGFPD.’’