Hi, I need some advice please: A Goodwe inverter was installed when we build our house in November 2019. This year we started to have trouble as the batteries did not charge out of Eskom when there was not enough UV to charge the batteries out of the solar panels. The installer made a few changes.  Shortly after he made changes and a software update three of our fridges and  two automatic gate motors were damaged. Seems like the transformers and fridge compressors failed. These equipment are on the inverter output as part of the installation.  Needless to say, after repairs to the garage doors it happens again and again, even after we put in spike prevention plugs.  The installer and Goodwe support does not seem to know what the problem is.  Is there someone else that have the same problems and know if there is a solution?  This is getting really frustrating as we have no answer after two weeks.  

Don't have this problem, but I can tell you this. The goodwe, while ongrid, sync with the grid supply and if there is in fact spikes, those spikes are sent through to the backup side as the inverter mostly react slow to the spikes before throwing the load on to the batteries. I would blame your grid supply first. Find out if others in your street have the same issues.

Most of the time if fridges are damaged from the power if the voltages are too low (especially the compressor), get a decent protection device that switches off the devices on low voltage. Builders and ellies and most hardware places sell them. They are about R700 each.

Another alternative is to put a small R700 ups between the devices and the power circuit that way if anything bad happens it will fry the ups before it fires the device.

I am NOT an electrician so do get one if you are not into DIY solutions

I wonder if it's clipping of the output voltage waveform. That can cause motors to overheat. Clipping is seen in Axpert inverters if the battery voltage is too low. I have no idea if that could carry over to Goodwe inverters.

My experience recently and still ongoing :
- Replaced 4 x 16VAC 50VA Alarm Transformers (R350. per pop) excuse the pun
- Replaced 1 x Electric Fence AC Transformer - (R750.)
- Replaced 1 x Battery charger board inside my gate motor. (R600)
- Installer call out (R500) since he is a friend of the family

I suspect the EZ meter is the guilty party here, but we will know once i receive the replacement meter to confirm and compare to my current meter

Long story short, Meter reports lower current than actually on the circuits, once you start adding higher loads - kettle, oven, geyser, then the meter shoots up to where its not able to support those loads, but in reality the load have long passed the actual currents - in general i could see about 2.5-2.8Kw under reported by the Meter.

More on this in a few days when i can give actual confirmation
Hope this helps someone to investigate if you have similar experience

 

I don't think the easy meter could cause this. What is the voltage between earth and neutral on the backup side when loadshedding? Do you know if the earth leakage works when loadshedding?

55 minutes ago, P1000 said:

I don't think the easy meter could cause this. What is the voltage between earth and neutral on the backup side when loadshedding? Do you know if the earth leakage works when loadshedding?

AC on Backup side N + E = 0.4 V when no load from the Grid
 

I would look at the incoming grid first. You can monitor that using the PV Master app, but it's hard to watch all day for a dip in power (most likely scenario). 

The batteries not charging suggests to me the following
1) Grid voltage was dropping too low, so the Goodwe (set for SA 230V) disconnected from the grid and relied on batteries and PV. You may not have problems if this happens when there's lots of PV and your loads are low, but it will not make the job of getting the batteries charged and keeping them charged any easier.
2) The power settings get changed to 50Hz default. Now the Goodwe will track the incoming voltage for a lot longer, so if the incoming AC dips to, say, 190V, the Goodwe will match that.

6 hours ago, Scra said:

AC on Backup side N + E = 0.4 V when no load from the Grid
 

That is fine. Unfortunately, I don't see how you will easily get to the bottom of this without some specialist equipment.

Yeah I'd recommend a wave analyser to see what the sine wave looks like in real time.

 

On the other hand, I think maybe its unfair to compare my equipment to the OP, because before getting solar, we changed most of our appliances to be inverter based.
Eg. the fridge is an inverter based fridge. You know, similar to inverter aircons. So the fridge converts the AC to DC first and the motor run at variable speed instead of full speed as with the older non-inverter based fridges. This means, the power is cleaned before it gets to the motor. The only non-inverter appliance we have left, is the maybe the microwave and definitely the pool pump. I am unsure about the bar fridge...but it doesn't run full power on/off so I suspect it might be ok.