Solar PV Hot water load diversion.

[alegood]

Okay so this is my setup.

 

1050 watts of solar panels

Outback Flexmax 80

1000 amp 2v traction batteries at 12v system voltage

Victron 12/3000 Multiplus
 

26 (?) Gallon (1050x450) Calorifier.

 

I'd like to add the following immersion heater.

 

https://www.advancedwater.co.uk/prod-232-255-2721.html

 

What is the best way to do this?

 

Many thanks

 

[WotEver]

Does the Outback include a ‘dump load’ output, or some other external way of knowing when the batteries are fully charged?  Does it have internal adjustable settings for deciding when the batteries are ‘full’?

[Robbo]

The outback has PWM load output which can vary the load for the amount of solar there is.   It needs to be coupled with a SSR (Solid State Relay) and it's best with a DC immersion (PWM not good for the Inverter).   It's prob best to search/ask on this forum for advice; http://www.outbackpower.com/forum/viewforum.php?f=29

[alegood]

Thanks for replying.

 

It does have a diversion output, which is 12v.  The outback wiring diagram shows it connected to a relay.  The immersion I want to use is 230v.  So I am at a bit of a loss as to how this is all wired together.

 

You can adjust float voltage, absorbtion voltage and time, and you can adjust the equalisation values of the Outback.

 

Alegood.

[alegood]

Thanks Robbo.

 

The inverter in this setup is going to be left on 24/7.  Would it be possible to use a relay from the Outback to switch on the 1.5Kw immersion circuit? And wire the second 2Kw immersion from the shoreline feed ?

 

Alegood

Good idea Robbo, I will ask on the Outback forum as well later today.

 

Alegood

[WotEver]

If the load output is PWM then it’ll be nigh on impossible to use it to feed an inverter. It would have to feed a battery to which the inverter was connected but then even if you connected it to a relay that’s not going to help because the 230V element is a fixed load. As has been said, see if any of the Outback users has sorted an effective solution. 

[alegood]

Okay.

 

Many thanks

 

Thought it might be a bit tricky!

I will definitely ask the Outback forum.

I will report back if there is a way of doing it.

 

Alegood.

[LEO]

Hi,

I have a similar system which powers up a 240v/1Kw immersion heater on my 4 Kw PV system at home, it's brilliant, but gets the water very hot. It's wired in and switched on 24/7, catching any surplus power after domestic use, once water hot surplus electric diverts to the grid. I will be interested to learn how you get on.

[Bazza954]

Hi, does your cylinder have a connection on the top for  the new immersion ? if not you'll need one of these

https://www.ebay.co.uk/itm/Essex-2-25-E2-SX-Immersion-Heater-Boss-Flange-CURVED-surface-cylinder-tank-e2-r-/291209819359

 

Bazza

[alegood]

Evening Leo, 

 

Is your system a grid tie inverter then?  I think they are built with immersion heaters in mind.  How big is your cylinder? How long does it take for a 1Kw  element to heat the tank?

 

Evening Bazza.

 

My cylinder has a boss on the top for an immersion.  I had it built in when I ordered the tank. Thank you though.

 

I've posted my query on the Outback forum.  I will see what their thoughts are.  In the meantime, anyone else's opinion would be most welcome.

[LEO]

3 hours ago, alegood said:

Evening Leo, 

 

Is your system a grid tie inverter then?  I think they are built with immersion heaters in mind.  How big is your cylinder? How long does it take for a 1Kw  element to heat the tank?

 

 

Hi,

I have a conventional PV system with a 'Solar Immersion' fitment added (Google 'Solar Immersion' for details). I have a conventional domestic hot tank with a top fitted immersion. I went for a 1Kw extra long heater (purchased from Solar units? on the internet), I chose a 1KW unit as this works when perhaps weather conditions are allowing the PV unit to produce 1Kw and also when using power for domestic use often there is 1Kw + spare to power the immersion as well as the appliance being used.

 

It heats up HWater quickly to a very high temperature, but I am not sure how much of the tank gets heated, some users suggest fitting a pump helps circulate hot water in the tank , improving the performance, but to date I am happy with the quantity of hot water produced.

 

My domestic unit produced 490 units in May and last quarter 970 units, this is down on previous years due to poor weather, I shall get a payment from nPower of about £190 soon.

 

Hope this helps, let me know if you want more info.

 

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