Importance of neutral wiring?
I am interested to hear from those of you with Sunsynk inverter installation experience and also Sunsynk technical directly on the importance of neutral wiring for proper functioning of the Sunsynk inverter. Do you ensure that there is no common neutrals between essential and non-essential loads with your installations? The picture below is an extract from the training manual which shows that the neutral from grid/gen and load are indeed common which indicates perhaps it is not very important but I would like to hear your views. To my knowledge it is mandatory in Australia to bridge neutrals but per the RSA electrical code the neutral wiring between essential and non-essential should be separated when using a backup or alternate power supply.
The reason I raise this question is that my Sunsynk inverter's load value on screen would be affected by heavy appliances switching on and off on the grid (non-essential circuit). Note - inverter settings were on full export with no TOU programmed and CT coil installed correctly. For example - My load would read 500W with only lights, security and router running. If the Geyser switched on the load would immediately jump to 2000W while geyser was running. If later on the stove switched on the same 500W load would be reduced to almost zero W on screen. After testing it was identified that there was different currents flowing through the neutral and live wires of the load output. The live wire was the correct current for appliances being used but the neutral wire would reflect a different "interference" current. The effect of this is that the TOU functionality would not work correctly as the inverter would be using the incorrect load power readings to control charge and discharge of the battery. It transpired that the inverter seems to read the current on the neutral wire corresponding with the readings on screen. This interference effect was fully resolved when the wiring of my house and DB were audited and all the common neutrals were identified and separated correctly. An earth fault was also identified on the non-essential circuit which was corrected as well. Everything is working perfectly now. I wanted to share this story as I thought it was important for the Sunsynk community to be cognisant of this and find out whether anyone had experience something similar.
Actually it's interesting on your comments, very much depends on the jurisdiction your are in.
The above is an example where the inverted can switch in and out the Earth bond when required as we are using a hybrid inverter which sometimes is required.
However that is another issue that can happen if you have a neutral ass bond and you make the Earth connection while the inverter load is an island mode, a feed in RCD could be tripped.