Only if you can’t hardwire any, or all of your CT's back to zappi or eddi units. Harvi will transmit CT data this wirelessly (subject to distance and certain obstructions) 

This indicates a loss of communication between the hub and whatever device is displaying the red LED.

We usually recommend no more than around 20-25m although in a lot of cases this can be much further. Each site needs to be assessed on an individual basis for anything that could obstruct or disturb radio communications.

Yes! You can extend them up to a maximum of 100m but you MUST use a twisted pair cable (cat5) for it to work and maintain correct polarity throughout.

Providing the ‘Grid’ CT is fitted then zappi/eddi will work perfectly. The solar PV CT isn’t compulsory, but it does give you your solar PV information on the zappi/eddi screen and also on the app giving you one place to view everything.

No! The zappi 2 has an A-Type RCD with 6mA DC leakage protection built in meaning no requirement to fit an RCD elsewhere

Please check the Time/Date settings are correct on every myenergi device.
On the Time/Date menu, check
• The Timezone is correct
• Auto DST is turned ON
• Update from Cloud is turned ON (if paired with a hub)

A red server light means that the hub is not receiving any data from the server. Check that the hub has an Ethernet cable to your router and that this cable is working OK by plugging in another device such as a computer.
(You should also try rebooting your router and the hub)

If your EV uses the ‘Type 1’ connection, then you will need to purchase an 'Untethered' zappi which can be used with all Type 1 & 2 compatible vehicles using your own charge lead.

Check that your grid CT is fitted and configured in your zappi/eddi (please see CT golden rules)