Immersun & Economy 7

[infinity]

Has any one installed an immersun alongside an economy 7 and found a way to tie the two in together?

We installed one saturday, well 3 in the same street with similar setups. All on economy 7 with an immersion midway up the tank.

Obviously when the E7 is on it will heat the water up overnight, which is pointless as the immersun will have nothing to do the next day.

so is there a way to wire it into the E7 leaving the E7 in place so in winter it can be used as normal?

What ways have you wired the units in a similar setup?

 

[onions1066]

Let me just say I know nothing about solar pv but can't you connect to the boost instead of the off peak immersion? Then they will still have both,

 

[infinity]

Immersun & Economy 7

They are connected to the middle peak immersion. But the customer wants to be also be able to supply the bottom off peak one for more hot water

 

[dgp1985]

Does it consist of two heating elements? If so take one feed from the E7 and another from the main CU with an override switch.

 

[snowhead]

Use a 20amp changeover (2 Way) switch.
Common to heater, Pv in one side E7 in the other.

Labelled Summer / Winter or P.V / E7 or p / £

 

[Worcester]

So long as the circuits are properly protected , wire in through a change over relay (aka contactor); simples (Chint make them) Works wonderfully.

When economy 7 not available, power will flow from immersun, when it is, it will flow from Economy 7

That way the client doesn't have to operate the switch.

 

[Worcester]

Why are you only supplying the bottom off peak one? Better to supply the top one so that they get hot water asap and use the relay in the immersun to supply the bottom one when the top one is hot, and then use the contactor (Change over relay) as mentioned above.

 

[Earthstore]

That makes sense, and would work very well.

 

[pwboston]

You dont change the wiring, it shows you in the instructions of the immersun to wire it the same way.

I have an Immerun and i have 2 elements with economy 7, from March onwards you dont need to use it, and in the winter you simply add the top or bottom element to come on with the inbuilt timer to come on during the economy 7 hours.

You no longer need the controlled circuit like I used to have as you have full control yourself via the immersun unit.

When you setup the unit you have to set it for 2 element system and its very easy to setup with the timers etc.

hope this helps

 

[infinity]

Immersun & Economy 7

Thanks for all info.

It is the middle peak element I supplied not the E7

Think il look at the contractor method with E7 energising turning off the immersun supply

The only trouble I see with this method is you can't control how much E7 heat you let through during the night time, as you want to save some of the work for the immersun unit!

 

[Worcester]

@pwboston, I can see how your solution works. It does however require and 'intelligent' user the other solution doesn't, it just means that they will always have hot water, some of which will have been heated by the immersun. It also depends upon when and how they use the water - showers in the morning or baths at night.

If the lower element is set to a lower level by the thermostat, this will also have an impact on which gets priority when the water is cold.. (legionella considered..)

For infinity's case either the contactor or the timer may work, it depends upon how the E7 has been wired into the building - we've seen some properties with completely seperate CU's and circuits for the E7 that stops the consumer from using those appliances wired in to those circuits on anything other than E7.

The only fully integrated solution is quite complex using the ImmerSun relay, contactors and a programmable immersion thermostat (different temperature requirments at different times of day). The only problem with that is that the only programmable cylinder stat available has just been declared 'end of life' and has ceased all production ... (we just bought 3 ) So working on our own version at the moment based on the OpenEnergyMonitor and a series of remote temperature sensors.

 

[infinity]

The E7 immersion on the tank has indeed been fed from a separate E7 consumer unit! which probably means only a contactor and change over switch will work