Article 427 & Heat Trace

[tim robben]

The title of Article 427 is "Fixed Electric Heating Equipment for Pipelines and Vessels" but in the Handbook under 427.1 Scope there is a reference that leads one to believe that it applies to other applications. In addtion there is a FPN under the definition of "Resistance Heating Element" to that effect also. Heat trace is often applied to piping to prevent freezing. Is it the intention of the NEC to require ground fault protection devices in these applications?

 

[tony_psuee]

Re: Article 427 & Heat Trace

Tim,

I can not say what the "official" intent of the NEC is, however my interpretation of 427, specifically 427.22 is to use GFCI protection when using heat tape. This has been followed when having heat tape installed on piping and on condensate drain pans.

Tony

 

[vanwalker]

Re: Article 427 & Heat Trace

2002 550.13 (E) 3 this is a start!

 

[tom baker]

Re: Article 427 & Heat Trace

My understanding is industrial "heat tape" requires GFPE, as it typically is 480 or 277. Residential applications use GFCI. I install short sections of heat cable in commerical applications and use GFCI protection.

 

[jerryb]

Re: Article 427 & Heat Trace

If you look through the Raychem catalog for heat tracing pipes (prevent freezing and maintain hot water systems) you will find that they require GFCI protection for all installations.

Also the protection is supposed to be rated for a 30ma trip, not the standard 5ma that you find on a standard GFCI receptacle.

 

[don_resqcapt19]

Re: Article 427 & Heat Trace

Tony,
427.22 does not require GFCI protection for heat tracing and using GFCI protection will often result in nuisance trips. The code does require GFP protection for this equipment. GFCIs have a trip level of 5 mA while GFP is 30 mA.

Tom,
All of the industrial heat trace that I have installed has been on 120 or 240 volt circuits.
Don

[ October 08, 2003, 04:33 PM: Message edited by: don_resqcapt19 ]

 

[tony_psuee]

Re: Article 427 & Heat Trace

Don,

Thanks for the correction of terminology. We actually used GF circuit breakers from Cutler-Hammer with the 30mA trip.

Tony

 

[iwire]

Re: Article 427 & Heat Trace

We have been installing a lot of 277 volt heat trace in the past 3 or 4 years.

The GFP protection is a pain, essentially a shunt trip breaker with an external "donut" CT that mounts in the gutter space of the panel.

The breaker is of course 277 volt but the control circuit is 120 volt so now you need to bring in a seperate 120 volt circuit and jump a hot and neutral in and out of each breaker, plus 4 control wires from each breaker to the CT, run the hot and neutral for that circuit through the CT, the hot ending up on the breaker, and the neutral to the neutral bar.

One problem with this is that the loss of the 120 volt circuit makes the breakers not GFP anymore.

I have never seen this addressed, I would like some sort of warning given on the loss of control power.

If you are at all interested in keeping it neat, it will take the better part of a day to do this.

Most times 20 amp circuits but 8, 6 or 4 awg for voltage drop, the panel gets to be full in a hurry.

You need to get wide tubs if you have more than a few of these CTs to install.

The ones I have worked with where made by Siemens.

[ October 08, 2003, 04:56 PM: Message edited by: iwire ]