GFPE

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hhsting

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Designer contacted manufacturer of Underfloor heat cables for big walk in freezer in grocery. The heat cables are underneath walk-in freezer inside the food warehouse.

The manufacturer came back GFPE is required however with freezer floor cable heating system installed in metal conduit under freezer floor, GFPE can cause nuisance trip/alarm and not typically installed. There may be some interpretation of NEC code that states if the system is monitored with alarm GFPE can be eliminated.

I don’t see any exception like that for GFPE. Does anyone here know if there is any in NEC 2014?
 
If the manufacturer requires it as part of the listing of the cables then it doesn't matter if the NEC requires it or not. Is that what they're saying?
 
If the manufacturer requires it as part of the listing of the cables then it doesn't matter if the NEC requires it or not. Is that what they're saying?

The are saying following:

“The heat cable manufacturer standard clarification requires GFPE for the heat cables. The heat cable manufacturer does not require GFCI to be used with heat tracing.

With that being said, on freezer floor heating systems installed in metal conduit freezer floor, the GFPE for the heat cables is not typically installed due false/nuisance trips. There may be some interpretation of the national code that states if the system is monitored that the GFPE can be eliminated. Since this underfloor heating system is monitored by a controller with alarm, it maybe exempt”

Is there any such exception in NEC 2014 or not?
 
The are saying following:

“The heat cable manufacturer standard clarification requires GFPE for the heat cables. The heat cable manufacturer does not require GFCI to be used with heat tracing.

With that being said, on freezer floor heating systems installed in metal conduit freezer floor, the GFPE for the heat cables is not typically installed due false/nuisance trips. There may be some interpretation of the national code that states if the system is monitored that the GFPE can be eliminated. Since this underfloor heating system is monitored by a controller with alarm, it maybe exempt”

Is there any such exception in NEC 2014 or not?
There are no exceptions. The code requires GFPE because of the possibility that GFCI would trip with heating cables. The manufacturer's instructions cannot remove a code requirement. If the heat trace is tripping GFPE protective devices, it has been damaged or was not manufactured in compliance with the product standards.
 
There are no exceptions. The code requires GFPE because of the possibility that GFCI would trip with heating cables. The manufacturer's instructions cannot remove a code requirement. If the heat trace is tripping GFPE protective devices, it has been damaged or was not manufactured in compliance with the product standards.

Just found please see NEC 2014 Section 427.22:

427.22: “Ground Fault Protection of Equipment. Ground-fault protection of equipment shall be provided for electric heat tracing and heating panels. This requirement Shall Not apply in industrial establishments where there is alarms indication of ground faults and the following conditions apply:

(1) Conditions of maintenance and supervision ensure that only qualified persons service the installed systems.

(2) Continued circuit operation is necessary for safe operation of equipment or process.”

I am not sure if my is industrial and would 427.22 even apply to my even if it’s industrial.
 
Pipeline or vessel? Um no.

Part I. General
427.1 Scope. The requirements of this article shall apply to electrically energized heating systems and the installation of these systems used with pipelines or vessels or both.
 
I agree with infinity that rt 427 would be the correct one for your application but in the event it is correct I think it is rare that ommission standards would be in effect,
 
I answered the vessel question in your other thread. A walk-in freezer is not a vessel.
 
I failed to use the term "not"in my reply. I agree with Infinity that Art 427 is not the reference for underfloor heat cables. There is no vessel involved.
 
Looking at one manufacturer data they referecen UL KQYZX which crosses to Art 424 Part V. 424.44 seemingly would appy for GFCI but only 110.3(B) for GFP.
 
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