13Amp switch on a radial circuit

[Cam90]

Hi,

If I have a 13 Amp fused switch in a radial circuit (not as a spur on the radial), and then continue the circuit round to other 13 amp sockets from the 13 Amp switch does that limit all the subsequent sockets to 13 amps shared between them all? Or does the 13 amp limit renew for each socket in the circuit?

Just asking because in my airing cupboard the electrician wired the immersion heater and underfloor heater onto the redundant shower radial circuit - and put both onto two separate fused switches (immersion heater runs as a spur from one of the fused switches). Is that allowed or will it overload the first fused switch if both the underfloor heating and immersion heater are on at the same time? Immersion heater is 3kw.

The fused sockets both look like 13A each but not certain.

Thanks, 
Cam.

 

[Murdoch]

Ignoring the fused spurs for a moment, what is the value of the circuit breaker in the fuseboard and what size do you estimate the cable to be?

do you use the immersion all the time or as a back up?

if the circuit breaker is 16A then this ultimately limits the load on the circuit.

It’s also probably worth checking the fuse rating of the underfloor heating

and dare I ask you if said electrician gave you any certification for his changes?

hope this helps

 

[Cam90]

The cable is either 6mm or 10mm. It runs firstly into a fused switch (unsure of the amps but i think it’s 13). This switch is for the immersion heater, and a cable runs from the tank to that first switch. From the first switch the cable then drops down to what I think is a 4mm, and goes into a second fused switch which runs the underfloor heating. So I think the effect of that is that the two sockets are on the radial circuit, and the immersion heater is a spur from that first socket?  The underfloor heating is only a small area. All of the circuits in the house (other than lighting) is on a 63 Amp rccb. The immersion heater is only a back up.
 

I don’t believe he did but I can’t remember!

 

[Murdoch]

Hum .... you won’t get 10mm and 6 mm into most fused spurs. Wonder how it’s actually wired?

what happens if you turn off the first fused spur?

 

[Cam90]

Just turned on the second one and it works even if the first is turned off. Which is a good sign I suppose! I guess that means the fuse in the first socket is only for the immersion heater, and the fuse in the second socket is only for the underfloor heating. So I don’t have to worry about the underfloor heating overloading the fuse in the first socket? Thanks for pointing that out - I didn’t think about that.