# Heat Trace



## STerry86 (11 mo ago)

Does SR heat trace have a capacitor?


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## joe-nwt (Mar 28, 2019)

?????? Are you an electrician?


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## Almost Retired (Sep 14, 2021)

STerry86 said:


> Does SR heat trace have a capacitor?











Self-Regulating Heat Tracing Technology


nVent RAYCHEM self-regulating heating cables can be used to protect pipes from freezing, maintain process temperatures for liquids, heat tanks, melt snow on roofs and surfaces, provide instant hot water at the tap and even to heat floors. As the inventor of self-regulating heat-tracing...




raychem.nvent.com





it doesnt appear that way
although there may be a capacitive effect from the semiconductor core
if you are trying to troubleshoot it, it seems that exposing it to cold and checking for current flowing may be your best bet


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## glen1971 (Oct 10, 2012)

STerry86 said:


> Does SR heat trace have a capacitor?


No.. Have you worked with it before? In a nut shell it is 2 bare wires separated by a semiconductor and protected by a nonconductive sheath. Then there is a braided ground wire around it and another outer protective sheath. The design of the trace determines what temperature it controls to.

Why do you ask if it has a capacitor?


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## 99cents (Aug 20, 2012)

glen1971 said:


> No.. Have you worked with it before? In a nut shell it is 2 bare wires separated by a semiconductor and protected by a nonconductive sheath. Then there is a braided ground wire around it and another outer protective sheath. The design of the trace determines what temperature it controls to.
> 
> Why do you ask if it has a capacitor?


Maybe because it has kind of an inrush when you energize it.


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## glen1971 (Oct 10, 2012)

99cents said:


> Maybe because it has kind of an inrush when you energize it.


Maybe? I asked in case the OP was trying to troubleshoot it and saw some weird meter readings. I've seen some people get hung up on a continuity reading between conductors when trying to troubleshoot it. They assume a continuity test should be "infinity" or how it "fails" a megger test line to line.


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## Peewee0413 (Oct 18, 2012)

joe-nwt said:


> ?????? Are you an electrician?


Doubt it.... 

Sent from my SM-G998U using Tapatalk


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## STerry86 (11 mo ago)

Doing some troubleshooting but was told to check the capacitor….. haven’t worked with it much but didn’t think there was one.

The temperature on the pipeline wasn’t at the set temp. So just did a capacitance test.


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## glen1971 (Oct 10, 2012)

STerry86 said:


> Doing some troubleshooting but was told to check the capacitor….. haven’t worked with it much but didn’t think there was one.
> 
> The temperature on the pipeline wasn’t at the set temp. So just did a capacitance test.


What kind of troubleshooting are you trying to do? Voltages look ok? What are you seeing for current? What kind of heat trace? Set temperature where? On a controller? Pipeline skin temperature RTD? Process temperature RTD?
In any troubleshooting I've done, I've never done a capacitance check on heat trace. Did your boss, or whoever asked for the test, give you an expected value? Or what different values could be interpreted as?


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## STerry86 (11 mo ago)

I was asked to check the power connection for a capacitance test. That is it. It’s and SR line on an insulated pipe. I don’t know what’s running through the pipe. 
I did the testing and give the results.
I was just curious about the capacitor thing, which was answered. Thanks.


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## Lone Crapshooter (Nov 8, 2008)

I just happen to have a RAYCHEM installation and maintenance manual (published in June of 2008). According to section 9 you can do fault location by measuring the capacitance of the cable. You need to know what type of cable you have and then you look up the capacitance per foot. That is in nF (nano-farads) than multiply that by the capacitance factor and that will give you the distance in feet of cable to the fault.
That will give you the cable length to the fault not the distance in feet of pipe. If you have traced pipe hangers. valves shoes, flanges and the like there could be a considerable difference in cable length v/s pipe length pipe length being longer.
Best advice start walking look for damaged, temporary or removed insulation new valve or anyplace that it looks like the pipe fitters have worked in the last few days.
Good Luck

LC
The Raychem manual is available as a PDF on the Raychem site. They talk about testing in section 7 in the newer version
Once again GOOD LUCK


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## Peewee0413 (Oct 18, 2012)

Lone Crapshooter said:


> I just happen to have a RAYCHEM installation and maintenance manual. According to section 9 you can do fault location by measuring the capacitance of the cable. You need to know what type of cable you have and then you look up the capacitance per foot. That is in nF (nano-farads) than multiply that by the capacitance factor and that will give you the distance in feet of cable to the fault.
> That will give you the cable length to the fault not the distance in feet of pipe. If you have traced pipe hangers. valves shoes, flanges and the like there could be a considerable difference in cable length v/s pipe length pipe length being longer.
> Best advice start walking look for damaged, temporary or removed insulation new valve or anyplace that it looks like the pipe fitters have worked in the last few days.
> Good Luck
> ...


That's all I know about capacitance on heat trace. Actually did it once in North Dakota 8 years ago.

Sent from my SM-G998U using Tapatalk


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## STerry86 (11 mo ago)

Thanks


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## CAUSA (Apr 3, 2013)

STerry86 said:


> Doing some troubleshooting but was told to check the capacitor….. haven’t worked with it much but didn’t think there was one.
> 
> The temperature on the pipeline wasn’t at the set temp. So just did a capacitance test.


There are other reasons that should be looked in to for the poor pipeline temperature.

If the trace is not working, a link on how to test:


https://www.drexan.com/pdfs/HD150729-1%20Testing%20and%20Troubleshooting%20rev1.pdf




1-the fastening system of the heat trace to the pipework failing. The heat trace could not be having the surface contact required.

2-the insulation is not the right R value. Or wet. If not properly cladded and sealed.

3-the heat trace is not properly installed. For the size of pipe and type of flanging/valve system.

4-the wrong Watts/ft was installed.

5-there is nothing wrong with the heat trace and the products flowing through the piping system is absorbing the pipe temperature at the point of measuring. Needs average
Measurements throughout the entire pipeline system.

Is this a process plant or a industrial application?

what pipe system are you trying to protect?


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