Sunsynk 5kW Hybrid Inverter: Output Voltage & Earth Bonding Query
I have a Sunsynk 5kW Hybrid inverter installation connected to a Hubble 5kWh lithium-ion battery and 3600W of solar panels in South Africa.
I have been experiencing some earth leakage (residual current) tripping problems on the grid supply, which I am trying to resolve.
I have measured the following output voltages from the inverter:
With hybrid inverter fed from grid supply Inverter only operation
(i.e. fed from battery & solar panels)
Live – Neutral 230V 227V
Live – Earth 230V 134V
Neutral – Earth 0.66V 93V
Question 1: Are the output voltages with inverter only operation correct?
It appears that the hybrid inverter is an inverter with floating neutral point.
Question 2: When switching from grid supply to inverter operation is the neutral to earth automatically bridged on the inverter output?
Some explanation is provided on page 20 of the Installer Manual (Version 4.0 (02/23/2021)) but it is not clear if a neutral to earth connection is automatically made when switching to inverter operation.
You need external contactor that will connect neutral and earth when operating in island mode. Inverter has output that can drive it, but you need to provide the contactor (or relay depending on current requirements).