Storage Heaters Dimplex 3.4KW

[andyww]

Hi All

Question - a Dimplex 3.4KW storage heater would presumably have a max current drain of 14.78A. Given that 2.5mm T&E is rated at 20A on a radial, would it be ok to run it in 2.5 T&E on a 16A MCB? Reason I ask is that I have only ever seen storage heaters run in 6mm (maybe because there were more than one heater on the radial?)
I would be running each heater on it's own radial

Thanks
Andy

 

[Mr Mark Sparks]

as you say all ok

 

[andyww]

Thanks Mark

Not had any experience of storage heaters so wasn't sure if they were rated differently and that's why I'd only seen them run in 6mm. - 2.5mm it is then

Cheers

 

[Mr Mark Sparks]

no you are right
they are pure resistive load 2.5 is ok

 

[andyww]

Thanks Mark

 

[scotsparky]

Even if it is only 1 heater watch out for the lenght of run as you may have exess volt drop.

 

[spark1]

Just a bit of advice..
If the installation has more than this one heater and they are all in the same c.u [usual setup], then I would install a 20A c.b rather than the 16A. Reason being that when all the heaters are initially switched on the circuit breakers can be loaded close to their rated current..if the c.b is not of a high quality then they tend to heat up. this combination of warm circuit breakers in close proximity to each other can in the long term have a detrimental effect on the c.b .and in some cases it can also trip it under full load: hence the reason in this instance for advising the 20A c.b...more tolerance to the thermal trip .


spark1

 

[revolt3k]

I've only ever seen Storage Heating wired in 2.5 T&E. I guess if the rating was large it would need a bigger cable (4 or 6 mm) but norally in domestic there on 2.5's

A Question i have tho is, when testing you can only do the dead tests as the power doent come on till late. How do you carry Ze and PSCC/PFC test out to calc Zs?

 

[Mr Mark Sparks]

i put zs down as a limitation and just do dead tests inc r1r2 ,as for ze again verify cpc continuity all the way back to source ie main earth bar and record a lim

 

[Spudnik]

Your Ze should be the same as the main CU.

As for Zs, this could be calculated and noted on the cert.

 

[spark1]

I always rig up a temp supply from the general supplies consumer unit to the off peak c.u and carry out a full functional powered up test. Reasons being.........

1. Confirmation that all will be well when the teleswitch powers up ,usually when the residents are in bed...peace of
mind scenario !

2. To allow all coatings of heating elements to be burn off at time of installation preventing unwanted fumes possibly
circulating in rooms inhabited by sleeping persons....especially children.



spark1

 

[Scott F]

Only thing with that is you have to be CERTAIN there is not an afternoon boost.
Otherwise R1+R2 you think your working dead,afternoon boost kicks in BANG