Fitting immersion controller in parallel with timer ?

[Scobo]

I recently bought one of these to switch on our immersion automatically when we generate enough solar power ... Water Heating with Surplus Solar PV - Solar
Unfortunately, our electrician has failed to show up 3 times to fit it.
So I'm thinking of having a stab at it myself as I have some basic knowledge of electrics and have fitted new sockets and light fittings myself in the past.
My question is, can I fit it in parallel with our existing timer switch and if so, does it have to be on the same feed from the consumer unit or can I use a second separate feed from a socket ?

 

[Worcester]

There are loads of threads on here about immersion heater timers / proportional control etc, in fact I believe that you have contributed on some of them, so I'll keep this thread to answering your specific question.

1) I will NOT comment on wether you should do this yourself on not, I'll leave that to others!

My question is, can I fit it in parallel with our existing timer switch and if so, does it have to be on the same feed from the consumer unit or can I use a second separate feed from a socket ?

2) In reverse, NO you can't feed the immersion from a socket you should use the dedicated supply, the sparks on here will give you all the reasons why.

3) You should fit this in PARALLEL to the supply to the immersion with the timer / boost control, so that effectively you have two switching controls, this and the timer, so effectively this switch will bypass the timinmg controls.

Programme the both the immersion and heating timer to come on AT THE END OF THE DAY, that way you still use whatever electrity this sends to your immersion, then the timer using your preferred source of heating will kick in and heat up the hot water if still needed.

 

[Scobo]

Thanks Worcester.
Had a feeling it might not be that straight forward.

 

[sedgy34]

Get another spark to do it, don't mess yourself

 

[Scobo]

Get another spark to do it, don't mess yourself

Any takers here ?
I've had two guys fail to turn up so far for this job.
I'm guessing its either too small a job for them or they're unsure about the product.

 

[Worcester]

@Scobo, given it's a home made device with no CE ratings or markings, I think you will have trouble getting any qualified electrician to install it

 

[Scobo]

@Scobo, given it's a home made device with no CE ratings or markings, I think you will have trouble getting any qualified electrician to install it

It has the CE markings just above the mains live connection (not easily spotted on the photo at first granted) ...

 

[jason121]

does it come with a power pack for the 12v

 

[Scobo]

No you need to supply that yourself.
I had a spare adapter lying around which works fine with it.

 

[jason121]

The jam jar put me of a bit, does the photocell have a lead on it and how old is the tank, does it have the thermostat in a seperate pocket

 

[Scobo]

Yes, it comes connected to the controller by a cable about a foot long although you can extend this by 20 metres apparently.
Do you mean our hot water tank ?
If so, it's at least 15 years old (we've been in this house 15 years).

 

[jason121]

yes hot water tank

 

[Scobo]

Sorry, I'm no spark or plumber but I'm assuming the stat is built into the immersion as the temperature control is on the top of the coil where the mains connects.

 

[jason121]

new immersions have thermo cut have to manual reset stat, two stats in series.

 

[Scobo]

Just to update, I now have the controller installed and have the light sensor attached to the LED on our import meter (an idea I pinched from another thread) and it's working great.
The switch now activates whenever the LED stays lit and there's enough excess solar being generated to run the immersion.

 

[liquidity]

Will that really work? Let's say your heater draw 1000 watts and without the heater running you're exporting 800 watts. So the LED on the import meter is on and your widget decides to switch on the heater. But now you're importing 200 watts so the LED on the import meter starts to flash and your widget shuts off the immersion heater. I'm guessing you get the picture - there are scenarios where the heater will cycle on and off like mad. Or have I missed something?

 

[Scobo]

Once the light sensor detects enough light (LED stays on), there's a 5 second delay before the relay activates and another delay when the LED starts flashing before it switches off preventing it from turning the immersion on and off rapidly.
I have it plugged into a timer set to come on around the time we start getting 1.5kw of generation and off around the time it starts to drop below that.
It's not the perfect setup and I'm sure some of the more expensive systems will be more efficient but it was cheap as chips and has provided us with hot water even on dull days.