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lv6548

yellowjeep2850

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hi I'm building my first system , and I'm using two of the mpp-lv6548 it says 4000 watt max per pv input . i just want to check my reasoning to be sure i do this right. when i use midnite solars calculator , i can get close to 4kw with 4 - 480w panels in series @ two parallel strings per pv input 3840 total each , so with all maxed out with the 4 total pv inputs it puts me at 15360 , does this sound correct ? i put in the applicable temperatures for my area so the max of 250vdc won't be reached , results are attached
i am always second guessing myself , everyone's input will be appreciated cheers!
 

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your fine on staying below 250 volts but will be over the 18 amp limit per input. MPP has told some members here that is a somewhat flexible limit. you may want to look a little more into that. from what I have read it wont hurt the inverters but will clip off the excess am[s. losing small amount of power.
I have the same system and a number of folks have used smaller panels that seem to be a better fit with the lv6548. Im using used 250 watt panels with 6s2p setup. I have 2 ground arrays with 24 panels each so 12kw total
 
hi I'm building my first system , and I'm using two of the mpp-lv6548 it says 4000 watt max per pv input . i just want to check my reasoning to be sure i do this right. when i use midnite solars calculator , i can get close to 4kw with 4 - 480w panels in series @ two parallel strings per pv input 3840 total each , so with all maxed out with the 4 total pv inputs it puts me at 15360 , does this sound correct ? i put in the applicable temperatures for my area so the max of 250vdc won't be reached , results are attached
i am always second guessing myself , everyone's input will be appreciated cheers!
Specs are similar to the 530W panels I have, I went with 4S and 4 seperate strings.

A little high on the amps, personally I wouldn't push it that far. I'd add another standalone or two SCC's myself. https://watts247.com/product/sc48120/ The latest version is supposedly 250VOC capable.

Amps make heat, I prefer to run electronics on the cooler side.
 
Most HF all-in-one inverters dump their SCC output into the high voltage DC node between battery DC to HV DC converter and PWM IGBT sinewave generating H-bridge. In the SCC they use a DC-DC boost converter to take PV input up to HV DC node. This means the PV array must be lower than HV DC supply inside inverter.

On the LV654, which is only 120vac inverter, the HV DC runs between 180vdc and 270 vdc. Its HV DC filter capacitors have a 315v rating that must not be exceeded.

They typically have a relay on SCC board that disconnects PV input if PV input is too low or too high in voltage. Their inverter efficiency spec is usually stated where the PV input voltage is very close to HV DC node voltage which gives the best DC-DC converter boost efficiency. Lower PV input voltage has lower DC-DC boost converter efficiency.

When you over-panel a SCC it cannot search out PV MPPT point without exceeding max input current so it should just go to its max rating and sit at that point. It must run panels above normal Vmp voltage of panels to reduce PV amperage output. Running at max PV input does put the maximum stress on SCC so hopefully it is designed with enough margin to run for long periods at the highest input power without overheating. Best not to let the inverter's environmental surrounding temp get too high so it does not get good heat sink cooling. The SCC heat sink is not that large. At 18 amps on each PV input, just the SCC rectifier diodes will generate about 30 watts of heating.

LV6548 Pict breakdown.png

HF inverter block diagram.png
 
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your fine on staying below 250 volts but will be over the 18 amp limit per input. MPP has told some members here that is a somewhat flexible limit. you may want to look a little more into that. from what I have read it wont hurt the inverters but will clip off the excess am[s. losing small amount of power.
I have the same system and a number of folks have used smaller panels that seem to be a better fit with the lv6548. Im using used 250 watt panels with 6s2p setup. I have 2 ground arrays with 24 panels each so 12kw total
yeah current is high , I emailed them and included spec sheet of panels and calculator result and they said okay on amps , more importantly to stay below voc..
honestly the results on the spec sheet are done in a perfect environment so i tend to think the nmot results are more of a real life scenario , am i mistaken ? and yes i would like to get amps lower , just finding it hard to get more watts , which panels are you using ?
 
yeah current is high , I emailed them and included spec sheet of panels and calculator result and they said okay on amps , more importantly to stay below voc..
honestly the results on the spec sheet are done in a perfect environment so i tend to think the nmot results are more of a real life scenario...
How often will you get the PV max solar production?

The max solar production will only occur around noon time with direct South facing and inclination adjusted for your location and date.
 
okay another question I'm thinking that I should populate all pv inputs , instead of fully populating only one input on each inverter .then later if needed i can bump up each run , according to my needs
your thoughts
 
okay another question I'm thinking that I should populate all pv inputs , instead of fully populating only one input on each inverter .then later if needed i can bump up each run , according to my needs
your thoughts
If you have it, use it is my motto. Everything runs much cooler when it comes to electronics. You also would not be affected as much by shading or cloud cover if you don't have strings in parallel.
 
It's a good way to go.
Just size the wiring for future expansion.
It will make it much easier to add on , later.
 
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