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Post by terminalbliss on Oct 1, 2017 8:00:13 GMT -8
   Hello all new to the forum. I just upgraded my Renogy 400 watt 30 amp PWM system to a 500 watt 40 amp MPPT system. i move the panels from parallel to series. Replaced the PWM controller for the ROVER 40 amp MPPT controller. At that point everything was fine. Volts were in the 70's and getting 16 - 23 amps right on target. Then the new Renogy 100 watt panel arrived. I checked it voltage 20.8v. Added it to the series. Here is where the trouble starts. The controller has over voltage error 101.9 to 103.2 volts on the screen. Go to the roof check the 400 watt string reads 82.6 and the new panel is still 20.8v so open circuit is 103.2v when all 5 panels are connected I removed the new panel from the string and everything is happy again. The ROVER 40 amp is rated for 520watts of PV. How? Is definitely not in one string of 500! I saw i could get another 100 watt panel and do 2 strings of 300 but that would only work for a 24v system. (this install is on an RV a very 12v system.) So how does one get 500watts into the controller but keep it under 100 v's PV? |
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Post by tattoo on Oct 1, 2017 8:20:52 GMT -8
I have basically the exact same system you up graded to and mine is working great.... I don't have a Rover but it is an older Renogy 40amp MPPT CC..... The most I have ever seen is 100v and that was just for 2 seconds... It's usually around 80v... I bet you have your panels exactly at the angle to the sun and don't have any trees.... I would take out one panel or go up to a 60a CC.... That's what I'm going to do...
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Post by terminalbliss on Oct 1, 2017 8:33:42 GMT -8
 They are flat on the roof of the RV (This is FL so it doesn't take much to get full sun). I looked at the old 40amp MTTP it can handle 150v PV. Too bad they don't sell that one any more it would fix the issue in a snap. |
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Post by tattoo on Oct 1, 2017 8:48:07 GMT -8
Yea I think I got one of the last ones they had because right after I bought it I noticed it wasn't listed for sale anymore.... So it looks like I got lucky?? If I were you for right now I would take out one panel.. How many batteries do you have in your system??? I have 6 6v in series.... It does everything I had hoped it would....
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Post by terminalbliss on Oct 1, 2017 9:05:20 GMT -8
Yep took one out so I'm running on 4 panels. Just have one 12v 125Ah battery. I ordered another but wasn't home on Fri to get it. I got the vmax solar tank Renogy resells. So Monday i will have 2x 12v 125ah batteries will have them in parallel.
Still wonder how the Rover is able to get 500watts PV maybe 2 x 250 watt 12v stings? That would keep the volts down and the amps under 40.
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Post by tattoo on Oct 1, 2017 13:55:33 GMT -8
My Batteries are 215ah 6v so the way I have the hooked up I have 645ah..... They do everything and more than I need at this point...... My batteries float almost every day.........
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Post by rabird on Oct 2, 2017 10:56:14 GMT -8
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Post by terminalbliss on Oct 2, 2017 17:25:47 GMT -8
Yes the controller shuts down production. 0 amps going out to the battery. The controller does stay powered on just won't produce anything until the volts drop below 100. Yes the math says if i had 4 150w panels the at optimum it would be 71.6v. My 5x100 watt panels at optimum should be 94.5v but in reality were 103v.
From another thread about the Rover 20 you spoke about the controller clipping energy of an over sized array was connected.
I think that is what i will do. Get one more 100w panel then do 2 strings of 300w. This will keep the volts below 100v and get max watts 520w at peak (80 watts getting clipped). My only worry is the heat that will be generated.
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Post by rabird on Oct 3, 2017 4:21:10 GMT -8
zip file manual from SRNE solar, ML-2440 www.srnesolar.com/index/down/id/84.htmldoes mention clipping. does mention shutting down if over voltage. If is rare for a panel to make it full power, heat reduces power, sun angle, clouds etc. That's why you may want to over watt a controller so you get closer to full output. In the cold that can make more than rated output but that requires tilting to the strong sun. |
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