Trace Heating Cable 230 volts

[cstewart37]

[FONT=&quot]Hello all,[/FONT]
[FONT=&quot]I have been asked to install a trace heating cable to a domestic hot water system in a school, designed to maintain the DHW at 55oC, the trace heating cables have to be taken to within 500mm of all terminal fittings & outlets (toilets, showers, classroom sink units & the main kitchen). This is the equivalent of running a flat PVC twin & earth cable surface along the surface pipe work. A 230 volt cable with no mechanical protection I am looking for regulations to quote to the site agent why this is a bad design:

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[FONT=&quot]I have no problem fitting the cable to the pipe work in the attic but it’s the exposed surface runs in the public areas that I would have a problem with. [/FONT]

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The normal system design would be to install a pump with a return pipe back from all the outlets back to the DHW boiler.[/FONT]

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Regards,[/FONT]

[FONT=&quot]CS. [/FONT]

 

[Des 56]

528.3 is a section that may help
possibly 528.3.1

Brb of course

 

[UNG]

My first thought would have been that a 110v system would have been better in the exposed areas but then again a pipe at 55°C would have to be protected from touch to prevent burns in areas where the staff / public / pupils have access. Not sure why you would be trace heating pipes to toilets unless they are using a hot flush to prevent infection

 

[asillien]

Hi CS,

This is not an uncommon occurrence these days. Maintaining 55C on single flow pipe work is more cost effective and energy efficient than a recirc system. Its not equivalent to running a twin and earth as trace heating cables have to be manufactured to BS 62396 among others which requires them to be robust etc. All trace heating cables I know of have a braid therefore have adequate electrical and mechanical protection. I don't agree with the 110V suggestion offered. They will want it to conform to ACOP L8 which is for legionella prevention. As long as you install it correctly and insulate the pipes correctly (very important) there will be no issues. Speak to the guys at Raychem ([email protected]), they are very knowledgeable and they offer a 5 year warranty. They will even give you a materials list. You need to ask about HWAT.
N.B you will need to use type C circuit breakers as FCU's will blow on switch on.

Thanks