Growatt Solar Inverter PV Isolation Low
Is your Growatt Solar Inverter showing a PV Isolation Low message?
When your Growatt solar inverter is operating correctly the inverter light will be a solid green. When the light is red it indicates that your inverter has detected a fault with the system – the particular fault details are displayed on the screen.
Growatt Solar Inverter PV Isolation Low – What does it mean?
According to the Growatt solar inverter manual a PV Isolation Low message on your inverter is telling you that the inverter has detected a problem with the insulation on the system. That’s helpful isn’t it? What this means is the system has detected leakage of electricity in the system to earth, and this condition is called an earth fault. The following list are some of the common causes of solar power earth faults that would make a Growatt solar inverter display a PV Isolation Low message:
- Moisture ingress in the solar panels
- Moisture ingress in the cabling, plugs, isolators or inverter
- Damage to cables in the solar power system
The first thing we recommend you try is a reboot of your solar power system.
Rebooting Your Growatt Solar Inverter
It is possible that the error you are seeing with your Growatt inverter is just a glitch which will be fixed by a system reboot. To reboot your Growatt solar inverter please follow these steps:
- Turn OFF the solar supply main switch (or inverter AC isolator if present).
- Turn OFF the PV array DC isolator.
- Wait for the inverter screen to go completely blank and the red fault light to turn off.
- Turn ON the PV array DC isolator.
- Turn ON the solar supply main switch (or inverter AC isolator if present).
- Wait a few minutes while the inverter boots back up.
If immediately after restarting the inverter you see the error message “PV isolation low” unfortunately it appears you may have an issue with your system which is going to require the services of a solar accredited electrician to find the fault and advise you further. If you are in South East QLD somewhere near the Gold Coast or Brisbane area we can help.
For further advice please complete the form above under the URGENT heading and we’ll assist you further.
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Hi Simon.
I have a growatt 5000mtl about 8 years old. Since the wet season arrived I’ve been getting the dreaded pv isolation low fault each morning. So i switch off the 3 input isolaters, reboot them 10 seconds later and it starts no problem. It can be raining, and will still restart. Does this sound like a inverter problem. Been doing this for 30 days straight.
Hi there fellow Growatt inverter owners..not too much goes faulty with the inverters themselves. However around the time when many of these units were being sold, most solar panels were manually sealed into their frames..and the process was sometimes less than perfect. Water /moisture can wick it’s way into the edge of the glass laminate and through a complex process it actually can reach the bus bar strips that are closest to the glass edge. From my experience it is possible to take down a panel…allow it to dry out thoroughly over a period…not just a few days, then apply a top grade silicon sealant along the glass frame interface. What also can contribute to the problem developing in the first place is when the panels are mounted at a low angle making it easy for water to remain sitting along the lower edge of the panels. But as I’ve explained all is not lost..Also in earlier panels the diode box was largely unsealed, and on foggy days with 100% humidity, the exchange of air in the box is enough to increase the earth leakage. BUT..after many years seeing this effect.apart from the leakage delaying the switch on of the inverter , it is not really a problem.
Hi Javier, you could try and take some measurements of the strings with a Meg Ohm meter, it sounds like you have an earth fault somewhere. This may be due to moisture getting into the solar panels, moisture in an isolator or damage to the solar cables.
Thanks for your question, you really need to take some resistance readings of the DC strings with a Meg Ohm meter. Put it on the 500V range and make sure that both positive and negative cables at the inverter to the solar panels have a resistance of greater than 20 MOhm to earth. If the resistance is less than that you may have an earth fault somewhere on the solar panel side of the system, if the resistance is higher than 20 MOhms it may be a problem with the inverter. I hope that helps!
hi, I have a Growatt 8k mtlp us, it doesn’t show any alarm and it works great, but when I measure PV – to earth it show a 180v, and there is also a voltage on each pv+ to earth, that happens only when the inverter is working, there is no alarm and the inverter works fine, I have already tried to disconnect the ground and disconnect the Strings one per one, and the voltage value between pv- to earth is still at 180. Should I leave it like this?