3 x 2kw heaters

[youngun]

Hi Guys
I am looking to install 3 x 2 kw heaters in a barn and am slightly lost as to the best way of switching. Draw is around 26.1A and volt drop over run of 18m is 8.46v. 2.5mm t&e should do it but what is best means of switching. Client would like them on timers too.
Cheers

 

[RF Lighting]

A time switch with an over-ride switch switching a 30A contactor feeding a DP isolator local to each heater.

You are right on the limit for a 2.5mm² T&E cable

Personally I would fit 4.0mm²

 

[youngun]

Cheers mate. 18m is the absolute extreme by the end it may be only 15-16m

 

[RF Lighting]

I was thinking more for the current carrying capacity.

2.5mm² is rated to 27A when installed to reference method 1

Your proposed load is 26.1A (at 230V). You can't get a 27A MCB so the next size up is 32A.

This means you have a cable rated to 27A protected by a 32A MCB, which is not allowed.

Therefor if you install 4.0mm² T&E which is rated at 36A when installed to reference method 1, you can protect it with a 32A MCB with no problems.

 

[Steve]

You're doing this for a client? Yet asking for advise on a DIY forum. Please explain.

And why did you just say the distance is less? Are you trying to get away with using some scrag ends of 2.5 you had lying about? DO IT PROPERLY and use 4mm!

 

[youngun]

yes it is for a client and yes we are on a diy forum but tell me where else do i go for expert advise. you guys seem to know your trade so thats why i am here. I am nearing the end of 2330 c&g and am working with another qualified sparks, but it would be nice to give some answers to problems so i can learn properly.

 

[Steve]

yes it is for a client and yes we are on a diy forum but tell me where else do i go for expert advise. you guys seem to know your trade so thats why i am here. I am nearing the end of 2330 c&g and am working with another qualified sparks, but it would be nice to give some answers to problems so i can learn properly.

Yep, I do know YOUR trade (I'm not a spark) But seriously, if you stick around, you'll learn a lot from the guys here. But if you'd explained to start with that you were still in training and working with a "proper" spark, I wouldn't have been to brusk, and I apologise for that.

 

[youngun]

no worries matey but talk about in at the deep end. I always knew this was never gonna be easy and would prefer to ask twice rather than guess once

 

[Pensdown]

Dimplex do a range of panel heaters with night set-back, frost protection and grouped time switch control.

Seems to easy to be a solution

 

[kai]

Another way is to install a consumer unit with B10 circuits for Each 2kW Heater (IB around 9 amps each), and have din-rail clip on timers etc in the same box, to control the heaters etc. A much neater solution with all controls etc in one box.