SwitchVanDam

Hey all!
 
So something has been bugging me about these Luxpower inverters for a while now, today I finally decided to investigate a bit further and this seems to have confirmed my suspicions and its quite frustrating...
 
I have a voltage protection device connected before my inverter circuit breakers (where Eskom gives power to the inverters). The voltage protection device allows me to see the voltage & current in realtime. I noticed a couple months ago that even when the load for the house is being carried by PV or if I am running on PV & Batteries, there is always current draw being displayed on the voltage protection and this current draw figure varies from time to time and is anywhere from 2.8A to 3.8A when there should be no draw from Eskom.
So I decided to stop being lazy and investigate further. I removed the cover of my DB board and used my clamp meter to assist me. Now I do not expect either the voltage protection device or my clamp meter to be 100% accurate but I do expect them to give me a fairly accurate reading. I understand the clamp meter is probably less accurate in this instance.
 
So before I started this test, I ensured that my inverter settings were as such to force the inverter to use PV & Battery only, no grid usage as per the below screenshot.

 
 
 
So below you can see a comparison of the clamp meter & voltage protection device both detecting current.
One reads 3,9A and the other 4,5A - this confirms to me that there is definitely current flowing

 
 
So I gave the Luxpower inverters the benefit of the doubt, maybe the voltage protection device is somehow consuming the power... although it seems a bit odd, lets try confirm this. So I turned off the breakers giving Eskom power to both my inverters and suddenly there was no usage displayed on both the voltage protection device & my clamp meter as can be seen below.

 
 
 
Now this does concern me and puzzles me a bit, I can understand that the Luxpower does not have an external CT coil and you have the CT coil offset to assist with calibrating it. By default mine was on 20W, I adjusted this (after I turned on the breakers, so my inverter had grid) to 199W and then to -199W and I did not see much (if any) difference to the readings on the voltage protection device or the clamp meter.
 
If we call it an average of 3,2A, since this is basically 24/7 that usage adds up quickly.
3,2A x 230v = 736W
736W x 24 hours = 17,66kWh per day
17,66kWh x 30 days = 529,8kWh in a 30 day month... Its a significant amount.
 
To be fair, this would not all be offset by solar anyways, there might only be around 7 hours in a day where this usage is offset by solar.
3,2A x 230v = 736W
736W x 17 hours = 12,51kWh per day
12,51kWh x 30 days = 375,3kWh in a 30 day month... A potential loss of 154,5kWh per month because of this.
At around R4 per kWh on the higher tier, this works out to around R618 per month.
 
 
So now, does anyone know why the Luxpower does this? Why does it draw soo much from the grid when the loads should be covered by PV or PV & Battery and it should not be drawing from the grid?
Also does anyone know whether the same is applicable to the Sunsynk/Deye inverters & Solis inverters?

If the inverter is earthed, no. Earth leakage is an enhancement on this protection, especially where plugs are involved.

Nb please be careful of starting a refrigiration compressor when it is still under pressure.  
If a compressor was running and is switched off and on in a short time, it tries to start against back pressure and the compressor can be damaged. 
To stagger the restart I'll suggest you get a couple of different Refrigiration Surge protector plugs. They have a restary time delay of between 2 to 5min .
I know the Clearline have a 5 min, my Ellies one has 2 minutes and the Safy Volt I supplied to a friend was 3 minutes. Your fridge will love you for using this device. LoL
If you can go to a supplier and ask them to test different models to see what delay they have because sometimes different units of the same supplier have n little different time delays. 
First test 1 and see if it is fast enough to catch your power dip or surge.