rfl

Good news. I was the initial poster on this thread. I let it lie for a while but decided to see if Deye/Sunsynk managed to sort out their MPPT algorithm which seemed to get bogged down in a less than ideal power point. Manual cycling of the string forced a full rescan and usually the MPPT then found the best power point. Not ideal. I recently updated my 8kW Deye to firmware Main: 6027-1724. Selected "MPPT Multi point scanning" in the "Advanced Function" menu under "System setup" and viola problem solved. In any case for my shading scenario. Much, much better. See below. The partially shaded string (PV1) now gradually improves its power output until it is unshaded and similar to PV2. Been tracking it now for a few weeks. It is not a fluke. I would like to believe that Powerforum and maybe this thread helped to make Deye/Sunsynk aware of the problem which they seemed to have solved. Not sure for their other inverters but it must have been a universal problem.

I assume "deep" refers to how far they scan either side of the current maximum for "something better". I have seen somewhere that some companies actually punt the fact that they scan the full curve continuously or at least very often but that it does lead to increased inefficiencies.

Dear Powerforum community members. I recently installed a Deye 8kW inverter with 10 x JA 540W panels and a couple of batteries. Panels are two strings of 5 each facing the same direction and having the same slope. Works like a charm except a curiosity that I picked up. In the morning one string is subject to partial shading (PV1) due to the house structure until about 10h15. On a cloudy day with distinct clouds interspersed with full sun both strings track one another closely until about 7h00 when the unshaded string (orange color) moves ahead slightly and attains the maximum power as appropriate for the irradiance level and cloud cover. The partially shaded string (blue curve) produces less as one would expect but still produces well. At about 10h15 when both strings are unshaded, they track one another almost exactly. See figure below. It seems that the MPPT’s are “awake” and the panel diodes are working well. On a really diffuse cloudy day most of the irradiance that the panels see is due to diffuse reflections and there is really very little difference between the two string outputs even though the one is supposed to be partially shaded up to about 10h15. The overall level is however significantly lower that full sun. See below. The curiosity that I picked up is during a cloudless day. In this case all starts well but then the partially shaded string gets bogged down “goes asleep” at a very low power level, 250W basically, up to the point it is in full sunlight when it suddenly takes off with gusto, See below. I believe that in this case the MPPT gets trapped in a local maximum on the overall string Voltage-Current curve and is unable to extract itself from this nonlinearity in the curve to achieve the global maximum. At first, I thought I had a defective MPPT, maybe I do but I swopped the strings between the two MPPT’s with no change apparent. Therefore, either both MPPT’s are defective, I have an issue with some panels, or this is a bug in the firmware. Interestingly if I cycle the power on the partially shaded string with the DC isolator the MPPT suddenly comes alive and then starts to track at a more appropriate power level for the partially shaded string (see below). It then actually tracks the partially shaded string beautifully until it eventually attains the same power output as the unshaded string. So, what do you guys and girls think, defective hardware or a less that efficient MPPT algorithm. I personally think it is the latter. A few clouds around, but not to many seems a good thing, early as it "awakens" the MPPT it would seem. Production is still good and in the greater scheme of things (full production day) I could probably live with this but being a perfectionist is a bugger. Ps. I have the very latest firmware installed for the 8kW Deye i.e. Protocol Version：V0.2.0.1 Lithium Battery Version Number：V0.0.0.0 MAIN：6022-1724 HMI：0000-C35D LCD Type：8100

Interesting. So are they planning to fix it with a future firmware update?

Then the relays become large and difficult to source. Relays above 25A are scarce and typically only available for 4 pole etc which is a massive waste.

Gentleman I am assuming that the current rating should be the same as the current rating of at least the inverter ac output. Am I correct? Many thanks

Is this legal? Neutral wire double tapping on "large" gauge wire in commercial AC combiner box. If I understand the wiring diagram correctly AC mains connection on the middle breaker will also require double tapping. What gives?