Wiring regs advice please

Should be on its own circuit, any fixed load greater than 2kW should be on its own circuit. 16A MCB, 2.5 cable and 20A DP switch with neon, then 1.5 or 2.5 HR flex to immersion.

 

No mate, as above, 2.5 back to the 'consumer unit'

 

This free weekend electricity from BG is really doing wonders for the immersion heater market... lol

 

One of the first lessons anyone should learn is you don't get anything for nothing.

 

Dont suppose you would want to use a 1.5 kw element off the ring ?
1.5 kW 27″ Immersion Heater Element
http://www.backerelectric.com/news/
Save a lot of wiring
RS

 

It might be worth reminding yourself of the guidance in the OSG.
It sayeth (4.5) that water heaters fitted to a storage vessel in excess of 15 litres.......should be supplied by its own circuit (and not supplied from a ring final circuit).
It does not specify the power requirements of the heating element.

 

I think you will find 4.5 is "Main protective bonding of plastic services"

I think you will find that is Appendix H5.

 

Deleted member 11267, apologies, I picked up an old OSG As you say, Its now in appendix H(5). But the basic sentiment of the guidance is the same.

 

The wiring regs say "get someone who knows what the hell they are doing or you an inbred brain dead muppet" (para 1:2:314). If you cannot find someone like that, just connect direct to main tails and check your house insurance for 'fire damage, acts of God and being a total numpty'. xx

 

Wiring regs..

 

I did mention this a while back. Just completed a nano job, run 1.5mm heat resistant flex off a 20 amp switch off a 1st floor ring final. Very light loading on the ring, maybe a stereo and a few lights. Towel rail, shower pump, yadda.

Don't really get why the guidance says you must run an immersion off it's own ctt, my design seems fine to me. I mean it's not like the electric works different for an immersion heater than it does for anything else. I did think it best to use a 20a switch rather than a fcu as I didn't really want to run the fcu near it's max.

What would have been a really cool design would be to somehow fix up a little 16a breaker and run it off that. I did think about a garage unit but I had problems with isolation and termination.

I'll let everyone know if the house burns down or what ever. The hardest part was replacing the immersion heater tbh. That WAS a ***** slap.

 

I'm sure it will probably be fine but you do have a 1.5 flex protected by a 32A MCB, I know its a fixed load but you could say the same thing about alarm fitters shoving the 1mm into the top of the switch contacts like they occasionally do.

 

What's the beef with 1.5mm on a 32 a breaker? Perfectly acceptable. Even a reg to allow it.

 

Adiabatic shift Mr C?