400W Solar Grid Tie Inverter Pure Sine Wave Micro Solar Inverter with MPPT Function for Home Outdoor PV Panel (AV210-230V)

I purchased this grid-tied microinverter to feed into the grid any power generated from two 200W Renegy solar panels I have on my shed roof. The inverter unit lives in the garage and is fed from the solar panels by two 6mm2 cables which are just under 10m long. The panels are wired in series because if I wire them in parallel then combined with the volt drop the operating window is far shorter due to the minimum start voltage not being reached until later in the day, and not at all on cloudy days. Also, the generated wattage is less, presumably due to the volt drop over the 10m run. With the setup as it is, and a good clear sky in the UK in June and July, I have just about seen a peak of 330W with my combined setup.Generally, it does what it says on the tin, but I have some gripes with it.1) It gets really hot and has to go into "protection mode" when generating just 75% of its rated maximum. If the solar panels provide anything over 260W then the unit heats up really quickly and pretty much as soon as it hits 69-70 degrees Celsius it goes into protection mode, which is great for safety, but it then takes about 10 minutes of cooling down until it reaches the lower threshold when it comes out of protection mode again and will start feeding in. So on a clear blue sky day with the sun perpendicular to the panels, I am having a duty cycle of about 5 minutes on and ten minutes off. Not good. Bear in mind the ambient temperature in my garage for those days was only about 22 degrees Celsius, maximum.To try and combat this I have purchased some heat sinks. I bought 4 RAM heat sinks and stuck them on the back to bring the unit away from the wall and provide more surface area for the heat to dissipate from the unit. I also bought a GFX card cooler with two fans, cut that down and stuck that on. The fans are not yet running as I am awaiting a PWM fan controller to arrive from China. Even without the two fans running the heat sink in the cooler has helped dissipate the heat a bit, and the on-off duty cycle has improved slightly. I hope when the fans are running it will almost negate the need for the unit to go into protection mode. it may also mean that the components in the inverter will run cooler and may be more efficient. Fingers crossed.2) Another big annoyance for me is that the unit interferes with any AV500 / AV600 HomePlugs plugged into the mains circuit near it. I live in rented accommodation so I can't be drilling holes in walls for ethernet cable runs, so I run TP-Link HomePlugs to get the ethernet and wifi around the house.When I tried to use a HomePlug wifi unit in the garage near the unit so the inverter can talk to the phone app it would not connect. I had no AV500 signal coming to the HomePlug. I had to move the HomePlug to a socket at the far end of the garage to get it to work at all. Also, I have a HomePlug in my office upstairs, but I have to assume that is also on the circuit for the garage as when the inverter is running it knocks my HomePlug out. If I take the HomePlug and plug it in another socked further away, it works like a charm.I have since done a little research into this and it does look like this can be a common problem with cheap inverters. I don't know yet if the same is true for expensive inverters. I have yet to find a suitable plug-in filter to combat this issue so it is ongoing. It means I cannot use the ethernet plug in my office during peak energy generation hours.*Conclusion*:So for a relatively cheap grid-tied microinverter, it does work. maybe if you don't pump in a wattage close to 75% of the rated maximum and you live in Iceland (the country, not the food shop), you may not see the overheating and hence the protection mode issue. If you are happy to add some additional heat dissipation you may also not see the protection mode come on.Also if you don't homeplugs or any other ethernet over mains data solution you won't see the other issue I have.I can't say that I would overly recommend this item for these reasons. Thankfully after complaining to the supplier, I did get a partial refund which provided the money to buy the GFX card cooler and heatsinks. The seller could not provide any technical help, as I assume they are just that; a seller.If I was to add more panels in the future I would only do so if I could afford a named brand inverter that I could purchase from a British mainland store, mainly for after-purchase help and support.