Immersion wiring requirements for wireless Immersun/iboost communication

[CBR600]

Hello there

As I understand it an immersion should be on its own dedicated circuit according 17th edition regs. As I am sure many of you have found this is often not the case with older immersion installations. Now we have a number of proportional controllers that have or can have wireless communication with a sender monitoring for export, the controller can easily be wired in on the immersion spur in the airing cupboard - So far as the controller is concerned this negates the need for the immersion to be on it's a dedicated circuit.

So my question is about whether the electrician wiring in the controller would be required to ensure that the immersion is on a dedicated circuit or is that some thing that they should just report as not conforming to the latest regulations?

Any views/advice very welcome.

Cheers and happy new year!

 

[pwboston]

Because your not altering the actual wiring you wouldnt be under any issues as long as you notified the client there is an issue (that said we pre notify and ask to wire it)

The main thing that IS required is making sure that the stat has the dual cut out, that is more important.

 

[CBR600]

Thanks pwboston, very helpful.

With regard to your last point, were the immersion to need replacing because of the lack of a dual cut out stat, I guess it would then need to be wired in according to the latest regs i.e. on it's own circuit.

Correct?

 

[yellowvanman]

Thanks pwboston, very helpful.

With regard to your last point, were the immersion to need replacing because of the lack of a dual cut out stat, I guess it would then need to be wired in according to the latest regs i.e. on it's own circuit.

Correct?

No.

The regs don't specifically say it needs to be on a dedicated circuit - just good practise. The on-site guide says it should be on a dedicated circuit, but thats not the regs, just an interpretation of!

There is also mention of not supplying immersions from a ring (Appendix ? - sorry only got BRB in office), but again the appendices are only informative and are provided as guidance only.

I have the same issue in my house, I'm guessing that the airing cupboard/immersion was a late after thought during the build!

 

[MCS Renewables]

Regulation 433.1.103
Green 17th edition page 425

fig 15A item 2
Ring final circuit not supplying immersion heaters due to current carrying capacity of ring cables exceeded for long periods.

You could argue that the immersun or iBoost unit is not supplying the full load for long periods which would seem reasonable enough.

 

[CBR600]

Thanks MCS

In many cases where a load controller is in place the immersion will never get full load simple because the PV won't ever generate enough due to peak capacity.

I take it that the current carrying capacity of the ring cables is only exceeded when the immersion is on full pelt with other devices being used in the house at the same time. This of course doesn't happen with the load controller in place (unless on boost).

 

[yellowvanman]

Don't want to get into a deep difference of opinion, but I try and make the regs work for me when I need them. Not arguing that its good practice to put an immersion on its own dedictaed circuit, but when you find one on a ring then I don't see anything in the regs that say you must change it!

Regulation 433.1.103

Doesn't specifically mention immersion circuits, but generally a load on a ring will be shared between the 2 cables, the closer to the 'middle' of the ring the more equally the load is shared, so reducing the chances of the cables carrying a load > 20A.

Green 17th edition page 425
fig 15A item 2
Ring final circuit not supplying immersion heaters due to current carrying capacity of ring cables exceeded for long periods.

As mentioned previously Appendices 'are informative, and are provided as guidance' - Page 276
Above the quote you have taken it also says:
'this can generally be achieved by' - so it doesn't really say you have to!

 

[marc8]

hi all
been to this quite alot recenlty installing immersuns for company they sometimes tell me dedicated
circuit which we have fixed price fit, but often they have overlooked it's fed via a ring, or others have spured of the system already.
not getting into regs here & all that, but have found sometimes increasing the length of the sensor cable has helped me sometimes a bit easier to get a bit of external cat6 or cat5 round to airing cupboard, still using immersion as it was before no change really, i just ensure that i put double pole fused spur in & ring in tact & readings good.