My best guess for the 4 pin AC connector is to have a bigger clearance distance between hot and neutral, given that the hot and ground are in opposing connector positions. Could also be that they use the same connector for 3 phase 4 wire inverters (3 hots plus ground), but that carries the risk of plugging a replacement single phase inverter into the 3 phase connector and blowing it up. It would not be for inverter versions meant for the 120V/240V single phase 3 wire we use on this side of the pond as our inverters always have wired terminals instead of connectors.
It was the dc disconnect key that caught me out, A jumper of heavy wire will get you out if the big plastic disconnect key is missing to link the two contacts in the centre of where the key should be.
I think those two components are MOV's however instead of thermistors. At least on the SMA's I have seen, they had the big replaceable MOV's (overvoltage protection) and sold them separately.
Hi, thanks for this, I was always told the 3 legged units were thermistors. Yes they sit in sockets and were supposed to be wear parts, but only I suspect if you push the inverter with high volts, cheers
@@TheInfoworks Those do look like varistors (MOVs), I agree. I hadn't seen the 3 legged type before though - these seem to have a thermal fuse inside in series with a normal 2 legged MOV, and the thermal fuse blows if the MOV is taking sustained overload of voltage, thus heating it up. The idea is to stop the MOV exploding/catching fire. The third leg comes from the junction between fuse and MOV, and is used as a 'monitor' output to check if the fuse is still good or not - sometimes connected to an led, in this case it sounds like it is used to trip the inverter out maybe ? I've learnt something today Andy. Cheers Dave
@@noakeswalker Dave, thanks for the info, from my understanding the voltage on the 3rd leg goes up as the heat rises caused by a high DC input voltage. This switches off the inverter. That's all I know and that the Aurora inverters have very similar 3 legged varistors (not thermistors). Cheers
Still have one of these, albeit a 2 kW unit up in the attic producing all our solar for more than ten years now :) Upgrading is not really an option since we'd be losing our overgenerous government subsidies that were handed out at the time (€450 per 1000kWh produced). Crazy politicians...
Hi, yes no need to change it, but it's getting to that age where I would add an external fan run through a plug in timer. See my video on extending inverter life. It's in the grid inverter playlist, cheers
@@TheInfoworks Hi! I would only upgrade it if would add more panels at the same time. As you said, these are solid inverters and I expect it to keep going for a while (hope I didn't jinx it). If you suddenly start injecting much more power than usual, apparently the energy company would come knocking on your door. Probably immediately installing a digital meter at the same time, which I want to avoid for as long as possible... Kind regards from Belgium, i'll check out that playlist!
Inside the boards are the same with the exception of the string board with DC fuse which is missing from the Windy's but if you are replacing a broken Sunny you can move it over. You do have to use a RS485 piggyback board and Sunny Data Control on a PC to change the Operating Mode parameter from Turbine to MPP-Operation: Maximum Power Point. Turn off and repower and you have a Sunny Boy. I have converted a WB2500 to a SB2500 doing exactly this. Just be aware that Windys relays operate a lot more than sunny's so the contacts wear out quicker but they can be replaced, error code needs resetting using RS485 piggyback and SDC on PC.
HI Andy ,I have a system with sunny boy inverters ,one of which has stopped working I have found someone to repair for me(I live in France)but i am unsure of how to safely disconnect and then reconnect once repaired.Could you help me with this ? thanks
