dual immersion heaters

[jacko57]

will a dedicated 16amp circuit, 2.5 cable , allow for two 3kw immersion heaters running at same time? have that now but when both on they trip the breaker after a few minutes of being on. all ok if just one on.
checked calculations and come up with 12amps for both.
Cheers
Jack'o

 

[Spark123]

(2 x 3000)/240 = 25A

 

[jacko57]

Cheers sparky, Feck i only calculated for one at 12 amps what cable will i require? 4mm? the 2.5 wont carry the load,at least 5 mtrs from board

 

[RF Lighting]

leave the existing 2.5mm² feeding one of the heaters, and install a second cable for the other heater.

 

[Taylortwocities]

It is a requirement for immersion heaters for vessels in excess of 30litres to have separate circuits and for them not be fed from a ring final.

Per RF above, you need to run a second feed.

 

[DanAir]

leave the existing 2.5mm² feeding one of the heaters, and install a second cable for the other heater.

Obviously the 16A MCB won't be sufficient if both cables come off one fuseway. I recently asked a very similar question (http://diynot.com/forums/viewtopic.php?t=130292) and the consensus was that two dedicated radials would be best but that a ring with 32A MCB would be acceptable (although some will argue that each immersion heater needs to be on its own fuse) and ideally each should be fed by a 13A FCU.

 

[Taylortwocities]

Usually a 16A MCB in the Consumer Unit and a 20A Double Pole Isolator Sw by the immersion.
No point having a 13A fuse with a 16A MCB - there's no discrimination between the two.

 

[Chri5]

Use one of these and your be fine with just the 2.5mm TE, accepting that both immersions do NOT need to be used at the same time.