Some DIY Checks for Grid Connect Solar Power Systems

Solar power systems are very reliable however from time to time some things can go wrong.

The voltage on the AC (grid) and DC (solar panel) side of the inverter is classed as low voltage so should only be altered by an licensed electrician. With this in mind there are still some user checks that could be carried out that might save a service call or might speed up your repair or warranty claim if you have to get someone out.

All inverters will have at least some LED indicator lights and most likely an LCD screen to communicate to the user the operating status on the system. Solar systems get there power from the Solar Panel side so the LCD are normally blank at night, some models will wake up if you press a button or tap the screen to check the day’s data but don’t be too concerned if the screen is blank at night .

If the screen is blank in the daytime it can only be two problems, a faulty inverter or no power coming from the panels. Just check that the PV array DC isolators have not been accidently switched off, these will be quiet large switches usually just to the left of the inverter.

If the LED indicators are working and the screen is operating but the system is not producing any power, check the screen or indicator lights for a fault code.

A common fault code is the GFI or ground fault. This is a safety feature that works buy measuring any leakage current to earth. If there is excessive current leaking to earth out of the system the inverter will shut down and try not to make the problem worse by alloying power to flow from the panels.

The best thing to do is to shut the system down and turn it back on again, there will be a shut down procedure on the inverter or in the main switchboard, turn the AC isolator off (just to the right of inverter) or the “Solar Supply Main Switch” in the switchboard and then turn the “PV Array DC Isolators” off, wait for a couple of minutes and then turn the DC isolators back on then the AC isolators.

Once the inverter has enough power supplied from the panels it will begin its self check procedure that will take at least 60 seconds. In this time it will test the circuits for leaks to earth. If the fault was temporary and has passed it will restart and operate, if the Ground fault appears again it’s time to call solar power store.

Another fault display is “Missing Grid”. This indicates that there is no AC power available at the inverter. Check AC isolator and solar supply main switch are on.

The inverter manual will have a list of the fault codes applicable to your inverter, we usually just type the model number and the fault code into google there will be someone who has had this problem before and the best way to fix it. If the inverter is still under warranty and there is a fault code on the screen, take a photo of the fault code and the name plate with model and serial number on it and send it to the claims department. Manufactures are aware of any problems with their products and if the fault is one that can be only fixed by a new inverter this will start your warranty claim, just be sure to follow the manufacture warranty claim procedure so it all goes smoothly. Normally they send a replacement to your house and then you call us to come and swap it over, we stick the old one in the box and send it back.

You may also be concerned if your system is not producing as much power as it should be. A good logic check in Queensland is to times the kW rating of your panels by 5 if you have good sun exposure ( no shade) you will get about how many kW hours your system should do each day. Example 5kW of solar panels x 5 peak sun hours = 25 kW hours per day. This is an average so will be a bit more in summer and a bit less in winter.

If your output is up to 20% down the solar panels will probably just need cleaning, you can do this by shutting the system down and using a soft brome and water clean the panels. Don’t use any detergent as they tend to make the glass a bit sticky and can make the panels get dirty again quicker . Be careful on your roof with the water, you don’t want to slip and break your neck. We can clean them for you if you like. We use a purified water system that is used for cleaning windows.

Anything more than about 20% down on output you’re likely to have panels that are able to provide power to the system. The panels are arranged in groups to fit in with the amount of roof space and the input parameters of the inverter. Most larger inverter will have at least 2 inputs into the inverter. If both inputs are equal and your inverter output is 50% down logic says you have a problem with that group of panels. Just check both your “PV Array Dc isolators are on, other than that you’re going to need a service call.

Micro inverters

A microinverter system has a small inverter under every 1-2 panels up on the roof. They will have some form of display device which can be connected to the internet. These systems will still have a “Solar Supply Main Switch” in the electrical switchboard that you could check is switched on, and if it is on could turn it off for a couple of minutes to try and do a reset.

An advantage of having a system connected to the internet is the manufacture can login and check for any system problems. If your display device is operating and you have internet connection the first thing to do after trying a reset is to contact the service center of the manufacture. The display will have a serial number which they will use to login to your system and try and diagnose the problem. This will often save a double call out as the service center can send you any replacement equipment to your house and help organise a technician.


No posts found

New post