Those numbers are based on the Vmp and Imp. The numbers you calculated are correct for the max. I had made this drawing thinking of figures it would operate at under most conditions. The higher figures would still be under the units rating for voltage. The amperage is limited to what they are capable of drawing. Just like your 200 amp main service doesn't force it's current on your small appliances.
That is what I based my plan on. But this is the area that I have the least experience so I am thankful for input.
Thanks for your ideas I have limited experience with the pv side of things. I don't want to let the smoke out the Inverters so I am grateful for cautious advice for sure.
True.
Key word here, 'should'...
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That is valuable information. Thanks for the reply and explanation. This is why I decided to document my build.True.
Key word here, 'should'...
We've had this discussion lots of times here about over-paneling with various brands/models of AIO's and charge controllers... It really just depends on the brand/model. Victron and SolArk both advertise in documentation that if over-paneling on amps, the controller will limit itself and not over-amp past its safe limit.
When the PV controller is doing an MPPT sweep (to locate maximum power point in watts), it pulls down the voltage (which brings the amps up), by lowering resistance in the circuit, if it pulls it all the way down to 0 ohms (short-circuit), during this sweeping, it could potentially draw high enough current to damage itself.
You'd think they would design it to simply not draw more than it is rated for. I would hope this, and like to see every manufacturer operate with this standard. However, it is not confirmed that every brand/model has this type of protection as a default safeguard.
Here was the official note which came from an agent at SanTan Solar, who had been in communication with an MPP Solar Support rep:
"
Ok, definitive answer from Andy Y. with MPP Solar Support Team:
"Please don't worry. PV input current 22A is ok and it will not cause the unit damage. We suggest that please keep the max PV input current within 25A. Thank you."
"
Refs below:
MPP-SOLAR LV6548
I'd have to go to four to NOT rewire ... with three I'd need to rewire: two used for single phase 120V, the third for 240V appliances (I think - I haven't done the load calcs), which means I'd have to basically pull apart my main panel and separate the two systems. Trying not to spend an extra...MPP LV6548 lower than expected PV power
Hey all, I have one MPP LV6548, currently with a string of 4x450w (50.5 Voc) panels in series. It is a very sunny day here, no cloud cover, but I am barely getting any input power. At the moment I am getting 184.6 V, but only 23 W of PV power and current is only sitting at 0.1 A. I have...
I'm just recommending to be safe and make sure. I can only go off of what the manufacturer Support team is recommending here. I personally don't know if going over 25a Imp in the circuit will hurt it in the real world, but if MPP Solar Support team is saying to keep it under 25a, that is a strong sign to me that maybe I should.
Fortunately, we can test the circuit to see what is the most amps it can draw at 0 ohms using an amp clamp, and if we go over on the test, then perhaps Raurre can ping MPP Solar Support for himself and see if possible to get their blessing that it is acceptable to do (that they will still hold warranty on them)...
Behind my Inverts are two layers of 1/2'' cement board. It has been painted that's why it is hard to tell what it is. The bottom cabinet is 1/8'' steel with a 1'' air gap between it and the wall it is mounted to. I welded a 1x1 angle iron on the back to serve as a spacer. Inside the cabinet i used the 1/8 boards as a insulating barrier for the 48v circuits.
Got it! Looks amazing!
Thanks. You are definitely correct on pointing out fire hazard concerns. The picture on my profile is from a panel where a mouse chewed a 16 awg wire running to a shunt trip in a 1200 amp 480v service. The arcing started a chain reaction that lead to the hole burnt through the panel enclosure. If not for the air space behind the metal enclosure the building would have burnt down before the main breaker tripped. By the way the mouse did not survive the event.
After I have read all the input of others on this forum I think I should change my system wiring (shown above). By removing the ECG bonding screw from one of my Inverters N/G relays . After second and third guessing my own conclusions just looking for some input about doing this before moving forward.This is the way I am wiring my system. It would never have the neutral and ECG bonded at more than one point at any given time. Since the two inverters communicating the way they are designed will both either be in bypass or inverting at the same time the system will only see one source.
