frost protection/heat tape - Electrician Talk - Professional Electrical Contractors Forum

chrisg · 11-03-2009, 01:14 PM

hello.
I have been given the task of pricing/installing jobs to install heat tape on caravans, theres about 16m of pipe on each, with the potential of 20+ caravans. i have never used heat trace before and have never really priced any jobs before but should make 22.5% on materials being a relative to a wholesale manager.
ideally i would like to find out the most profitable way to install.
i have discovered that you can buy pre terminated/fixed length cable with thermostat and power cable built in.( they cant be cut to length)
or self regulating cable which comes in drums and seperate terminating kits and possibly need a seperate thermostat.
i was also wondering if it would be worth the hassle of adding a spur to the socket circuit or pricing for it to be on its own breaker?
ive not really looked into the price of above options yet.
any feedback no matter how vague or in depth would be aprreciated please.

John · 11-03-2009, 05:51 PM

On this side of the Big Pond we call the them mobile homes. I prefer the self regulating heat tape due to fact that a lot of the water piping is plastic, which melts fairly easlly. I have seen the nonregulating heat tape that is controled by a thermostat get hot spots and melt the plastic pipe and sometimes start a fire. Not Good!
The self regulating heat tape just needs to be cut to lenght, install end terminations and install into a electrical junction box(or a plug). A thermostat is not required due to the fact that the cable controls the temperature.

The tape that I use is made by Raychem. http://www.tycothermal.com/uk/english/

scott_8222 · 11-05-2009, 07:45 AM

We use self regulating heat tape on most of the big transfer pipes and installation is a breeze. The brand is Thermon http://www.thermon.com in the top right corner the drop down menu will give you a UK option

Docara · 11-06-2009, 05:02 AM

Hi Crisg

As the other posters have stated use self regulating heating tape it WILL save you stress.

A couple of points (and not meaning to tell you to suck eggs!!!) make sure you consider insulation around the pipes you are lagging

And second Does this sort of thing come under "special Locations" under the 17th Edition (I don't know!!!) I know caravan sites are specifically included now in the regs (Yes I Know - I should have upgraded by now

)

Just thinking if the pipes in question are outside the 'Equipotential' zone you will probably have to supply them via an RCD if 240V (sorry 230v to our Euro 'friends'

Unless they could be classed as fixed equipment AND insulated accordingly (mechanical protection)

Docara

sparky105 · 11-06-2009, 04:54 PM

Quote:

Originally Posted by John

On this side of the Big Pond we call the them mobile homes. I prefer the self regulating heat tape due to fact that a lot of the water piping is plastic, which melts fairly easlly. I have seen the nonregulating heat tape that is controled by a thermostat get hot spots and melt the plastic pipe and sometimes start a fire. Not Good!
The self regulating heat tape just needs to be cut to lenght, install end terminations and install into a electrical junction box(or a plug). A thermostat is not required due to the fact that the cable controls the temperature.

The tape that I use is made by Raychem. http://www.tycothermal.com/uk/english/

don't forget to use a gfci

John · 11-06-2009, 05:41 PM

Quote:

Originally Posted by sparky105

don't forget to use a gfci

Would a RCD be required in the UK?

Docara · 11-08-2009, 01:18 PM

Hi John,

I'm not 100% certain and I don't have the regs to hand but I wouldn't rule it out.
The problem with all these types of forums you are not on hand to see the context of the installation. The OP has to make their own decission based on their own expertise and experience. Our regulations as such, are only a guide to best practice it is down to the professionalism (or not) of the sparks concerned to make sure that their installation (work, repair whatever) complies to the relevant sections of the regs.

Whether or not you are aware we have an earth AND have to earth extrenuous (SP) metal work, metal incoming pipes structural steel etc. The heating tape is resistive what happens if the tape shorted to ground (caravan) would there be the possibility of making the metal work of the caravan live but not allowing enough current to flow under fault conditions to trip a normal fuse / breaker? Now I don't know the answer - I doubt it but because I'm not doing the installation I'm covering all bases

In the UK caravan site, mariners, agricultural sites etc are classed as special locations or a high risk location so higher 'rules' apply to the installation.

Lastly, I do not know what type of supply is feeding the caravans or the phasing on the caravan site. A TT (Live and Neutral only -no earth) supply is more than likely so therefore the ALL circuits HAVE to be protected by an RCD most caravans site are a TT supply meaning there is only Live and neutral available so an earth rod must be installed close to the caravans.

If the supply is TN-C-S (PME) then the supplier will provide an earth connection then an RCD is required for all socket outlets which might supply equipment outside the equipotential zone (the caravan), Now as the news regs state than lighting cables ,if buried, below 50mm from the service also have to br protected via an RCD toy see why I brought up the issue originally.

My personal opinion is that there would be a good argument for the tape being regarded as 'Fixed equipment' thus not needing and RCD but it all depends on other factors on site.

Phew

Matt

chrisg · 11-10-2009, 08:46 AM

cheers for your input people.
Think i'l go for the self regulating stuff. Although its more expensive, (its not coming out my pocket and im making a % on it anyway!)Also does sound a lot easier and better quality, both in the short and the long run.

chrisg · 11-10-2009, 09:17 AM

17th Edition Section 721
ELECTRICAL INSTALLATIONS IN CARAVANS AND MOTOR CARAVANS
note 1: for mobile homes and residential park homes the general requirments apply.

Just made me aware of the fact caravans, motor caravans, mobile homes and residential park homes are all different in terms of wiring regs and in fact i should have pointed out I shall be installing in a residential park home! essentially a tin house!

This should answer questions about rcd's/special locations e.t.c.
A normal breaker will be getting used!

chrisg · 11-10-2009, 09:23 AM

Quote:

Originally Posted by sparky105

don't forget to use a gfci

what is a gfci?

sparky105 · 11-10-2009, 08:12 PM

Quote:

Originally Posted by chrisg

what is a gfci?

here in ontario all out door heat trace is protected by ground fault curciut interupter.(gfci) however required or not unmonitored tracer should be gfci protected in case of fault or short it is safer and more responsible.

sparks134 · 11-10-2009, 08:51 PM

So everytime the ice is melting and water runs in GFCI, you have to reset it!!! Come on!!

John · 11-10-2009, 09:18 PM

Quote:

Originally Posted by chrisg

what is a gfci?

A GFCI and RCD are almost identical except the trip rating and time frame. A GFCI will interrupt the circuit if the leakage current exceeds a range of 4-6 mA of current (the trip setting is typically 5 mA) within 25 milliseconds. A RCD has trip ratings of 10-300 mA depending on the application. I am familiar with RCD’s but not their application.

John · 11-10-2009, 09:27 PM

Quote:

Originally Posted by sparks134

So everytime the ice is melting and water runs in GFCI, you have to reset it!!! Come on!!

Does this have something to do with the wire not being in conduit or is it that you don't understand how to install the product?
I have installed the Raychem heat tape on metal roofs, rain gutter, plastic pipe and copper pipe using GFCI protection with no real problems. Check out the website and learn something...............

http://www.tycothermal.com/uk/english/

sparks134 · 11-10-2009, 09:31 PM

Quote:

Originally Posted by John

Does this have something to do with the wire not being in conduit or is it that you don't understand how to install the product?
I have installed the Raychem heat tape on metal roofs, rain gutter, plastic pipe and copper pipe using GFCI protection with no real problems. Check out the website and learn something...............

http://www.tycothermal.com/uk/english/

o!!!