Changeover switch

[Tinbum]

Thinking about it again, I think I would use a change over contactor wired the same as the changeover switch but with the coil of the contactor powered from the hive. No need then to manually change over any switch or press any buttons.

[ALAN/ALAN D]

Still not sure of what is required. ?

Do you want the Hive and the Iboost to send power to the same heater at the same time.

Single Immersion Heater connection Where a single immersion heater is fitted the wire link (supplied) should be connected. This joins the Boost output to the controlled output allowing the grid Boost function to remain available via the Solar iBoost. From 16A MCB or 13A fused outlet To Immersion heater Link (as supplied)

[Tinbum]

Alan, In the original post Joeboy said;

"I fancy adding an easily accessible change over switch in the loft so we can change from I boost PV to Grid timed."

[Countrypaul]

My understanding is that the iBoost outputs a DC voltage (not sure what 240?), surely that means the negative from the iBoost is not the same as the neutral from the mains?

Also doesn't the boost on the iBoost just switch on the heater (DC voltage?) as I don't see a separate output for the boost (I don't have a unit so am merely looking in the installation instructions). If so doesn't that mean there is no way to trigger a relay/contactor as it is impossible to distinguish between a divert and a boost? If so, then going back to a DPDT switch so the immersion is fed either from the iBoost or from the mains (Hive) seems to make more sense imho.

[Tinbum]

I don't know much about the iBoost but most diverters work by switching the AC on and off very rapidly. The output is still ac. That output can't be used to run a relay but often the diverter will have an additional output that is either on or off which can be used for an immersion. That output could also run a relay or contactor.

(I wasn't proposing using that but to run it off the hive output).

[Countrypaul]

This is taken from the iBoost installation instructions:

"The output from the Solar iBoost+ is
modulated DC and cannot be measured with
an AC Voltmeter.
Note: The outputs are + and – (not Live and
Neutral) and are not referenced to L, N or E.
If measured, a voltage may be present
between either output and earth"

I assumed that was the reason for the following statement in the instructions:
"
There must be no control of the immersion heater(s) by any equipment other than the Solar
iBoost+. In addition, there should not be any additional source of power connected to the
immersion heater. The Solar iBoost+ will replace any Boost controls or Hot Water Timers.

Failure to comply will result in damage to the Solar iBoost+ and invalidate your warranty"

[Tinbum]

This is taken from the iBoost installation instructions:

"The output from the Solar iBoost+ is
modulated DC and cannot be measured with
an AC Voltmeter.
Note: The outputs are + and – (not Live and
Neutral) and are not referenced to L, N or E.
If measured, a voltage may be present
between either output and earth"

Now that is interesting!!

[ALAN/ALAN D]

I havent got an Iboost.

The SW output is timed. You set the on off times. This can feed the Hive if you want remote control On / Off to over ride the Iboost.
The Hive out put feeds a solid state relay. ( Less power used )
Or the Hive can feed a contactor ( More power used )

The Iboost data sheet page 6 does not show any supply cable connected to the L of SW ???
Might have an internal connection. ??? Or the drawing is wrong. ???

Link to P.D.F. file.

https://www.marlec.co.uk/wp-content/upl ... ual-v2.pdf

[Tinbum]

I guess that if you are on GO that their would be no need for the hive as you just set the 12.30 - 04.30 in the IBoost but if on agile or similar flexible tariff that (no hive) wouldn't work.

[Joeboy]

This back from marlec

'am afraid your proposed installation will not work with the Solar iBoost.

I have attached a copy of the Installation Instructions for your perusal.

The ouput of the Solar iBoost+ is not standard 230VAC. It is a rectified AC which presents as DC and its PWM also.

It would not handle any sort of backfeed of 230VAC at all.

The Solar iBoost+ will need to be powered by continuous grid power, and must be connected directly to the immersion with no other devices between the unit and immersion.'