rbc

Good day everybody. I was wondering if i can get some input/opinions. I have a 5kw dye inverter connected to 6; 540w panels; running a 5kw greenrich battery. The system is just over a year old now and within the last 2 weeks i have noticed 2 things that weren't present before. firstly i noticed the sound the relay in the inverter makes when grid power goes out and comes back on; only the power doesn’t go off and my meter is still on; the AC led also stays illuminated, indicating grid power is available; however the grid icon on the lcd display shows off grid. This happens intermittently and can be at any time of the day. The condition lasts for about a minute and then you can hear the relay again and the display shows on grid again. When selecting the grid icon on the display all parameters shows normal apart from the current which drops to about 0.1A in the “off-grid state” which then picks up back to 0.9-1.0A when on grid again. secondly: also intermittent. when the panels are producing power a vibrating noise emits from the inverter sort of like a vacuum cleaner running in another room if that can explain it and the inverter gets quite warm to the touch. my system has been running smoothly up until i noticed the above mentioned. I also had a technician come look at it yesterday, but they were unable to find anything wrong. if anybody could please advise it would be greatly appreciated.