using amps in and out regulation on classic

[mahendra]

i am currently adding a few more solar panels on my classic 150,which is functioning at 12v nominal,however the the set of panels hooked up would be too much than what the classic can handle in total wattage. (6 phono 250w,vmp 30.0,voc 37.8,imp 8.3 in two strings of 3 total of 1500w).i want to know if using the amps in and amps out setting on the classic can be used to limit the input and out amperage of the panels when functioning at peak levels,without harming the classic.i do not plan on keeping it this way forever just until my 48v inverter arrives.please advise.

[boB]

yes, this should be fine, Mahendra.

At least it's not something like 15kW of solar on one classic !

That I might worry about a little bit.

boB

[mahendra]

thanks bob

[laszlo]

Yes, I am also using the current limiting function of the Classic and it works fine.  Settable under Charger->Limits->MaxAmps In and Out, as I remember.  What the Classic does, is raise the PV array voltage when it is current limiting, so IV curve of the panels limits the amps output.

[mahendra]

thanks lazlo

[mahendra]

laszlo*

[Vic]

Also rely on Limits on the output current of Classics here,  as we really must use EA,  and EA currently (so to speak) only works with a single Classic.  So,  have two arrays wired in parallel (now) going to a single Classic,  limited to about 75 A output,  while we   *wait*    for the MN Bat Current Monitor.

Works fine here.   FWIW Vic

[Resthome]

while we   *wait*    for the MN Bat Current Monitor.

and *wait* and *wait* -  I guess this isn't high on the software priority list. Unless they are finding issues with the single wire hardware design. Hopefully there are a few out there in Alpha Test land by now.

[boB]

while we   *wait*    for the MN Bat Current Monitor.

and *wait* and *wait* -  I guess this isn't high on the software priority list. Unless they are finding issues with the single wire hardware design. Hopefully there are a few out there in Alpha Test land by now.

YaY !!   It's REAL close now !

I mean...  REAL Close.

boB

[Vic]

boB!!

That's great news!

Can just barely wait for it.   Thanks!   Vic

[mahendra]

nice !

[jimbo]

Lazlo, how far over the midnites theoretical capacity are you operating?  I'm planing on doing the same very shortly with some arrays facing different directions to try ad give me a flatter output throughout the day.  I don't need more than the peak output of one classic at any one time but would like some extra panels for winter cloud.

[Resthome]

while we   *wait*    for the MN Bat Current Monitor.

and *wait* and *wait* -  I guess this isn't high on the software priority list. Unless they are finding issues with the single wire hardware design. Hopefully there are a few out there in Alpha Test land by now.

YaY !!   It's REAL close now !

I mean...  REAL Close.

boB

            


Good to hear boB

[laszlo]

Hi, there was a question regarding my  current limiting on Classic. How much over capacity on the Classic.  I realize you could do that, but in my case actually, it's within capacity.  The array is 4.4 KW and 48V nominal system, so the Classic 200 that I have can support that no problems. The limiting factor I have is  the DC breakers in and out of the Classic  being 63amp, and also that I wish to limit max DC going into the batteries. Under  normal peak full-sun operating condition I have around 55-62 amps DC so this current limiting only steps in when let's say it's cloudy for a few minutes then the cloud moves away and so it's a cold array you and you get "cloud-edge" effect as well. With that, it  could easily pump 80 amps from array -- and that would be too much. So  this is what I use  the current limiting feature  -- basically to shave off  transitory peak amps.

bOB may have  more info on current limiting  over capacity -- we had a chat a while back about this. As I understand, as long as the Classic is operational it will raise array voltage and limit current. But if it goes belly up, then it will short the array.

So I would not recommend to do this in a production system, or if you do make sure that theoretical maximum current is handled by your  OPD and wire sizing.

[mahendra]

ok i fully understand i was trying to clarify that earlier because i don't want to fry my classic .since i am in the tropical regions i rarely see over or full output of my arrays only in situations like you mentioned laszlo(cloud edge effect pv amps and volts can really jump up in those brief conditions) .just a reminder the array will be 1500w at 12v on a classic 150, so i would be about  120w above the recommended wattage by mindite solar.However Bob mentioned earlier it would  be ok.