Hoping to get some advise or help if anyone's experienced a similar issue please??

I've had a Mecer 5kv inverter (SOL-I-AX-5VP) installed with a dyness 4.8kw battery, the system has been working fine through loadhsedding as a backup. 

This past weekend we've begun the installation of 6 x 545w panels. The plan was to have 3 sets of 2 panels in series then running down to the inverter in Parallel.

This has not happened yet as we've strung 2x panels in series giving a PV volatage of +/- 92volts running down into the PV Combiner box.
When testing the voltage at the PV combiner box the voltage is maintained at 92v BUT when switching the box on, the panel indicator on the inverter LCD picks up the panels and displays the PV voltage as 92v but as the load is increased on the inverter (even a load less than 1kv) the pv voltage steadily declines down to 49v on the inverter and remains untill the load is switched off, when the load is turned off or reduced significantly the voltage steadily increases back up to 92v.
A second concern is that while the voltage is at 92v and declining on the inverter a buzzing sound (almost backfeeding) is made by the pv combiner untill the voltage is reduced to 48v. it remains silent untill the load is switched off but starts buzzing again as the voltage begins to rise again back up to 92v?

Has any one experienced this or able to offer any adivse please?

Edited April 12, 20231 yr by Milo
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Yours is a PWM model. When the solar charger is working, unless the battery is very full, the panel voltage will get dragged down to battery voltage. That's just the way that these cheaper solar chargers are designed; there is no inductor to perform voltage conversion. So this is not an MPPT model.

The best that you can do is to arrange your panels so that their Vmp in good sun is just a little over the battery voltage at full charge. That way, Vmp is never too far away from where the panels operate, so you'll get reasonable power from your panels.