meetyg
Solar Enthusiast
- Joined
- Jun 4, 2021
- Messages
- 1,090
Hi there.
I have a 1200w no-name grid-tie micro inverter from Aliexpress (model GTB-1200).
According to specs, it should handle 22-50v input, on each one of its 4 inputs.
It has over-voltage protection.
The problem is that it seems to be out of spec, and accepts voltages upto around 36v.
For example, when I connect two 18v (etfe, 100w) panels in series, it works fine.
But I am trying to connect a pair of new glass panels (not in series, one to each port), and they seem to trip the over voltage protection, because each one outputs 40-45v, even when not in full sunlight.
I was able to verify this by manually shading the glass panel, bringing down the voltage to around 34v, and it worked.
These new panels are rated at around 450w STC each, which is a bit more than the 300w recommended input for each of the inverters 4 ports. I am skeptic that the actual output will be that, because of various conditions. Even if, I don't mind clipping of the AC output. But after doing some testing I'm pretty sure that the problem is over voltage, not over current.
Having that this micro-inverter was bought from Aliexpress, the seller hasn't been very responsive, giving me laconic answers.
Anyways, I opened up the inverter to see if there is anything I could adjust myself (like a potentiometer) but there isn't anything I could identify. Some similar Chinese micro-inverters have a potentiometer on them, as I have seen on YouTube, but this one doesn't.
I'm attaching a picture of it, if you guys have any ideas, I would greatly appreciate it.
Another thought I had was to somehow split the voltage, but I'm not sure of an affective way to do so. Some simple voltage divider circuits would require some resistors, I suppose I would need some seriously rated resistors to handle this kind of load. In any case, I wouldn't want to loose power turning it into heat with resistors.
Any ideas how to split the voltage in an affective way?
I know my use case is kinda odd, but any help would be appreciated.
I have a 1200w no-name grid-tie micro inverter from Aliexpress (model GTB-1200).
According to specs, it should handle 22-50v input, on each one of its 4 inputs.
It has over-voltage protection.
The problem is that it seems to be out of spec, and accepts voltages upto around 36v.
For example, when I connect two 18v (etfe, 100w) panels in series, it works fine.
But I am trying to connect a pair of new glass panels (not in series, one to each port), and they seem to trip the over voltage protection, because each one outputs 40-45v, even when not in full sunlight.
I was able to verify this by manually shading the glass panel, bringing down the voltage to around 34v, and it worked.
These new panels are rated at around 450w STC each, which is a bit more than the 300w recommended input for each of the inverters 4 ports. I am skeptic that the actual output will be that, because of various conditions. Even if, I don't mind clipping of the AC output. But after doing some testing I'm pretty sure that the problem is over voltage, not over current.
Having that this micro-inverter was bought from Aliexpress, the seller hasn't been very responsive, giving me laconic answers.
Anyways, I opened up the inverter to see if there is anything I could adjust myself (like a potentiometer) but there isn't anything I could identify. Some similar Chinese micro-inverters have a potentiometer on them, as I have seen on YouTube, but this one doesn't.
I'm attaching a picture of it, if you guys have any ideas, I would greatly appreciate it.
Another thought I had was to somehow split the voltage, but I'm not sure of an affective way to do so. Some simple voltage divider circuits would require some resistors, I suppose I would need some seriously rated resistors to handle this kind of load. In any case, I wouldn't want to loose power turning it into heat with resistors.
Any ideas how to split the voltage in an affective way?
I know my use case is kinda odd, but any help would be appreciated.