Hi. I have a 150/45 Mttp, I have two 330w panels in series, and two 250w panels in series. Both strings attached paralleled to keep the voltage the same. I understand that this is over paneled as 630w is max for my controller (12v lifepo4 system) however it’s mostly in the shade so is the reason for two strings.
My question is, when the Mttp reaches 630w it is supposed to ‘clip’ the current and watts of the panels to regulate and protect itself, but mine keep cutting out the wattage and current to zero for about a second, then getting back to 630w 45a again, then cutting out again over and over again. Is this normal ‘cliping’ behaviour? Or is this something else? Could this damage the Mttp? I have checked the temperature compensation, connections, DVCC and every setting I have (or can think of ), and can’t seem to find anything wrong.
BTW it’s managed by the smart shunt and cerbo GX with VEdirect cables, and temperature sensors, and DVCC controlled.
What does it do stand alone? I had to send back a 100/30 that had a problem tracking. It wasn’t easy because they have a power supply and test bench with constant current and voltage. I did have a spare 100/20 that I connected to the same array and showed the dealer it produced twice what I got with the 100/30 and they gave me a new one and had no probelm since.
Same problem you have would just lose the current and drop out, re-track the mppV.
Hmm. Yeah it is stand alone. And I’ve had it in use for nearly a year with the two 330w panels. No problem, I just moved to a different location and have too much shade. So added some panels. Only started playing up then. So it could be the problem. So not sure about returning it? How long does the warranty stand?
The warranty is 5 years. Stand alone means just on its own without external control. Can you try it without the Cerbo and just use Bluetooth, see what the results are, to rule out a setting in the Cerbo.
Also make sure that the battery BMS is not causing this to happen because it is getting to a high voltage or high cell voltage if the battery is not balanced. I do not expect this as it would be a huge coincidence to occur at the mppt limit, but do check anyway.