Hi guys. I'm a newbie here and could really use some help... 

I've installed a voltronic MKS-3KW-24VDC inverter with two 12V 200AH gel batteries. It's been almost a year since the installation and it works great. I've decided to add two solar panels in the past week. With everything installed, I then changed program 1 to SOL and set my battery back to utility voltage, etc. The PV panels worked great and did everything as it should. There were no issues until later that night when the Earth leakage that is connected to the mains (utility/Eskom) tripped and upon resetting the breaker there was no power. The main fuse for my house located in the municipality box along the road had blown. Thankfully the municipality replaced it early yesterday morning and the inverter continued to work well with the PV panels until a few hours later the main fuse blew again. This time it did not trip any circuit breakers or ELs on my DB board...

 

Thankfully the fuse was replaced last night, by this time it was dark and the PV shut down and the inverter was in line mode. However, the fuse blew again again! At this point it made me wonder that there might be a connection issue with the inverter but I was really confused as to why it does not trip any circuit breakers but blows the municipal fuse to my home. To clarify, I've never had this issue before and everything worked seemingly until the PV panels were installed and the inverter program 01 changed to SOL. 

I tried figuring out what is happening but I'm really confused. I came across a post discussing that the Earth and Neutral of the inverter should be bonded when operating in battery mode. Could this possibly be the cause?? I do not have any neutral and earth at the output bonded. If someone could share some thoughts if this could be the issue, and why will it only cause an issue with the PV panels installed and SOL as a priority, and not when I just have battery power as backup?

 

Any ideas??

Unfortunately I dont have all the answers. Turn off the main incoming power to your inverter, disconnect the battery/turn it off and turn off all power between solar and the inverter. Then with a multimeter in Ohms/continuity mode you can test between the EARTH and NEUTRAL at the inverter output side. if the reading is zero then the inverter has internal Neutral/Earth bonding which is correct.

 

Is the Earth leakage connected before or after your inverter?

 

Only reason I can think of why the outside Fuse is tripping and not your breakers is because fuses trip way faster than breakers, meaning your breaker is still deciding whether or not it should trip and then the outside fuse has already tripped.

Did you have an earth rod installed when your panels were wired in?

 

Hi guys. I'm a newbie here and could really use some help... 

I've installed a voltronic MKS-3KW-24VDC inverter with two 12V 200AH gel batteries. It's been almost a year since the installation and it works great. I've decided to add two solar panels in the past week. With everything installed, I then changed program 1 to SOL and set my battery back to utility voltage, etc. The PV panels worked great and did everything as it should. There were no issues until later that night when the Earth leakage that is connected to the mains (utility/Eskom) tripped and upon resetting the breaker there was no power. The main fuse for my house located in the municipality box along the road had blown. Thankfully the municipality replaced it early yesterday morning and the inverter continued to work well with the PV panels until a few hours later the main fuse blew again. This time it did not trip any circuit breakers or ELs on my DB board...

 

Thankfully the fuse was replaced last night, by this time it was dark and the PV shut down and the inverter was in line mode. However, the fuse blew again again! At this point it made me wonder that there might be a connection issue with the inverter but I was really confused as to why it does not trip any circuit breakers but blows the municipal fuse to my home. To clarify, I've never had this issue before and everything worked seemingly until the PV panels were installed and the inverter program 01 changed to SOL. 

I tried figuring out what is happening but I'm really confused. I came across a post discussing that the Earth and Neutral of the inverter should be bonded when operating in battery mode. Could this possibly be the cause?? I do not have any neutral and earth at the output bonded. If someone could share some thoughts if this could be the issue, and why will it only cause an issue with the PV panels installed and SOL as a priority, and not when I just have battery power as backup?

 

Any ideas??

A 3kva inverter can not cause the utility fuse to blow that is  normally rated at 80 ~120 amps you will need more that 23kw to blow the utility fuse. I think it is a coincidence that the fuse is blowing after installing the panels. From the point of view for council just changing fuses and not looking for the problem unbelievable.Most probably an armoured cable fault that is causing a dead short across the utility supply. Concerning the earth neutral bond that would not cause your issue and secondly the Voltronic unit does the bond internally. Tell the council electrician they need to megger the cable from the kiosk to your point of supply before changing fuses again. If your main incomer breaker does not trip the problem is not on your load side.

Edited September 14, 20232 yr by TaliaB

 

Concerning the earth neutral bond that would not cause your issue and secondly the Voltronic unit does the bond internally

Fyi the older models don't do the bonding automatically. I have a MKS-3KVA-24V and confirmed this with a plug meter as you suggested in another topic a few weeks back.

 

Fyi the older models don't do the bonding automatically. I have a MKS-3KVA-24V and confirmed this with a plug meter as you suggested in another topic a few weeks back.

Ok fair enough but i know the new version does the VM II and VM III does have the bond done internally 

Thanks @TaliaB. It did end up being a fault on the armored cable that had a short. It happened at exactly the period I installed the PV Panels which made it suspicious. But it's all sorted and working great. Thank you!