3 x 1.5kw heaters on one circuit

[Mabro22]

Hi,

been asked to wire 3 x 1.5kw heaters in offices in an old warehouse.

2.5mm radial - 20amp rcbo with 20amp DP switch with flex outlets

That sound about right?

 

[Pete999]

So it is my bad math was never my strong subject lol

 

[Pete999]

What Voltage are you using?

Ignore the question my bad

 

[Mabro22]

You could demolish the warehouse and relocate the business to warmer climes and have no need for the heater.

There's a lot you could do but I expect, like me, you have a customer on a budget and are trying to give them something that will work, is safe and is compliant.

What you are suggesting appears to fit those criteria.

That’s what I was thinking
But I think I’ll just go for 4mm radial with 13amp switched fused Spurs at each heater

 

[Dave OCD]

No worries Pete. We all make a mistake now and then.

 

[Dave OCD]

That’s what I was thinking
But I think I’ll just go for 4mm radial with 13amp switched fused Spurs at each heater

The invoice for the design consultation will follow shortly.

 

[Mabro22]

The invoice for the design consultation will follow shortly.

Haha thanks

 

[littlespark]

Has the heating requirements been calculated properly?

you may find that 3 x 1kW heaters would be enough.....



or..... you need something like 3 x 2.5kW!

 

[Mabro22]

Has the heating requirements been calculated properly?

you may find that 3 x 1kW heaters would be enough.....



or..... you need something like 3 x 2.5kW!

not exactly calculated, but as I’m installing a 4mm ring circuit, I’ll probs upgrade to 2kw heaters

 

[Pete999]

not exactly calculated, but as I’m installing a 4mm ring circuit, I’ll probs upgrade to 2kw heaters

Why a 4mm RFC? it is a recommendation that loads of > 2KW have their own dedicated circuit, IMO a 4mm RFC is the wrong solution.

 

[DPG]

Why a 4mm RFC? it is a recommendation that loads of > 2KW have their own dedicated circuit, IMO a 4mm RFC is the wrong solution.

But that recommendation is mainly aimed at people who may put large loads on a ring which is used for other things as well. This ring is purely for the 3 heaters.

 

[westward10]

Plus each load is 1.5kw.

 

[Pete999]

But that recommendation is mainly aimed at people who may put large loads on a ring which is used for other things as well. This ring is purely for the 3 hears.

you maybe correct, still don't like it

 

[Wilko]

For known long term loads I like to use a lower MCB loading limit of 60%, which would take that 20A up to 32A MCB and then cabling as required by the installation method etc.