Two solar iboost in one installation

[bigspark17]

One house two immersion tanks either end of the building, house has a good size pv array and battery back up, customer wants iboost on both tanks, now i dont see any problems with this unless both ct clamps would be cancelling each other out? Anyone with any experience of fitting two iboost in one property?
Thanks

 

[plugsandsparks]

Not used Iboost but can for-see some serious instability issues. How far are the tanks apart as a single iboost can accommodate 2 X3kw immersions (expected to be in the same tank but cannot see a reason why they could not be different tanks. Basically it prioritises one immersion until it hits its thermostat then switches to the second immersion. The iboost is using pulsed DC to allow it to heat the water at different rates to the maximum of the immersion, hence if its a 3KW immersion but there is only 600W available, it will heat the water just using the 600W, clever but looks a very specific stand alone product.

 

[saint]

One house two immersion tanks either end of the building, house has a good size pv array and battery back up, customer wants iboost on both tanks, now i dont see any problems with this unless both ct clamps would be cancelling each other out? Anyone with any experience of fitting two iboost in one property?
Thanks

You can only use one per phase.you can run two immersions off one Iboost though

 

[pc1966]

You can only use one per phase.you can run two immersions off one Iboost though

The specifications are only 3kW here:

Solar iBoost+ Specifications

View the Solar iBoost+ and iBoost+ Buddy specifications and find out why Solar iBoost is the UK's favourite PV acsessory.

www.marlec.co.uk

Of course you might be able to use a 4P contactor or a pair of SSR to switch two circuits both simultaneously but you would need to contact the supplier as it might have a fast switching cycle or even do proportional control where a contactor would get trashed.

EDIT: Yes, it does, uses "Pulse width modulation" so you can't use any simple means to double up. Still worth asking about options to do so, or to decouple controllers so they don't fight each other for surplice PV power.

 

[baldelectrician]

You could have a timer that (using a contactor) switches the loads between both cylinders, a cost effective solution as well.
As you know you may need other stuff (like a sperarte supply from a single MCB for both immersers, probably on a seperate DB with the contactor and timer built in the same. You could have a priority set up where one chages up first

Are there cyilnder stats on the water storage?

 

[bigspark17]

Update its a no go.

Reply from marlec

Thank you for your valued enquiry.

Unfortunately you will not be able to utilise 2 Solar iBoost+ units on the same property. The two units would constantly battle for the excess PV. The unit does have 2 outputs, fro use with dual immersion tanks. However this cannot be used for 2 tanks on opposite sodes of the building as the cable runs cannot exceed 3m.

 

[plugsandsparks]

Doesn't surprise me, however, their 3m rule is possibly one to probe at, how far would the cable be to the second tank ?

There are devices out there that can deal with this. I have installed Solar control for a 11KW DHW Cylinder and 2 X Buffer Tank immersions at 6KW each. So i can draw 23KW when the sun is out. I am using a KNX Power Meter to measure the Grid supply which outputs the value to the bus. I then use a number of SR Nor gates and comparators and delays to provide the control of each immersion using a KNX logic module. There is no partial power control of the immersions like Iboost, its just on or off at full power.

Stability whilst Sun is in /out and maintaining battery priority whilst simultaneously maximising the available Solar is the challenge.

 

[Hotwire]

Update its a no go.

Reply from marlec

Thank you for your valued enquiry.

Unfortunately you will not be able to utilise 2 Solar iBoost+ units on the same property. The two units would constantly battle for the excess PV. The unit does have 2 outputs, fro use with dual immersion tanks. However this cannot be used for 2 tanks on opposite sodes of the building as the cable runs cannot exceed 3m.

 

[Hotwire]

Update its a no go.

Reply from marlec

Thank you for your valued enquiry.

Unfortunately you will not be able to utilise 2 Solar iBoost+ units on the same property. The two units would constantly battle for the excess PV. The unit does have 2 outputs, fro use with dual immersion tanks. However this cannot be used for 2 tanks on opposite sodes of the building as the cable runs cannot exceed 3m.

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One house two immersion tanks either end of the building, house has a good size pv array and battery back up, customer wants iboost on both tanks, now i dont see any problems with this unless both ct clamps would be cancelling each other out? Anyone with any experience of fitting two iboost in one property?
Thanks