Classic does not leave resting

[Kiki]

Hello, my classic does not leave resting even though there is more than 60 v coming and batteries are on 48.5v.
(400amps Rolls batteries,2 kw pv). Classic worked fine for 4 month and then moved into resting and stayed there. Mode is on and solar. Did factory setting and started new but still resting. Thanks

[Halfcrazy]

Try Legacy P&O instead of Solar. 60V is to low to charge a 48v battery so the Classic is not waking up.

Tell us more details on the array and we can help recommend the best way to wire it

Ryan

[Kiki]

I have 8 panels (each 24v). 2 of each in series and then parelel to another 2 pack and so on.
I hope that makes sense. Thanks

[Vic]

Hi Kiki,

Thanks for some extra info,

BUT,  many PV modules that are referred to as "24 V"  are not really 24 V PVs.

What is the Vmp on the label on the back of the PV.  If it is around 29.5 - 31.5 V,  these are not 24 V modules.

A 24 V module has a Vmp between 35.4 - 36.5 V.  There are some of these PV being made now,  but they are not nearly as common as are the 30-ish V PVs.

Thanks,    Vic

[Kiki]

Hi Vic,

Yes I just looked it up they are just 29.7 vmp.
How do I arrange the panels then?
4 in series instead of 2?

Thank you
Kiki

[Vic]

Hi Kiki,

Well,  you have eight PVs now.  Strings of four will have too high a Vmp for efficiency,   and the Voc will be too high for a Classic 150.

So,  for now,  how about two strings of three,  and try to find a compatible additional PV for the third string?

It is too bad even some resellers of solar gear call PV modules with 30-ish Vmp,   "24 V".  This can cause many problems for many.

MidNite has a very easy to use String Sizing Tool that can help users get a safe and high performance Solar array configured very quickly:

http://www.midnitesolar.com/sizingTool/displaySizing.php

More later,   Good Luck,   Vic

[boB]

Yes, the voltage isn't quite right for a 48V battery and a Classic 150.  That is, unless it is always warm where he is.

If the ambient temperatures is, say, 77 degrees F most of the time (25c) then it will probably be fine with
4 modules in series because the Voc would always be lower than 150 V.

[Vic]

OK,  thanks boB,

Perhaps I was too absolute in my statements.  Strings of four PVs with Vmp of 29.7 V result in about 12 V higher than the String Vmp of one system here.   This system here,  can run HOT when in Float with light loads -- Vin of about 122 V.  But when in Float,  in particular,   would expect the Vin to Kiki's Classic to be in the range of 135 or so volts  with warm PVs and some output current.  This sure seems too extreme to me.  Especially in the conjectured "warm" climate,  which might mean that the power electronics are running in a warm/hot room ...  more conjecture.

I should have said that,  personally,  I would not run Vin this high,  but that it is not my system,   so who am I ...  ??

Kiki noted that the system had worked for four months,  and then didn't with strings of two ...  and Legacy P&O may work fine for strings of two ...

Back under my rock,  where it is 92 F inside the cabin ...    FWIW,  my opinions,  YMMV,    Vic

[Westbranch]

makes a lot of sense that 4 months ago it worked OK with cooler temps, March or April, and as the temps increased, the output would fall slowly till there isn't enough V to come out of Resting...

[Vic]

YES,  Wb,  that was what I was alluding to ...   FWIW.    Vic

[Westbranch]

AH ha....  at least this heat hasn't addled my brain totally..  more ice! ... forecast is for another 5 days around here... sorry, no sweaty emoticon... 

[boB]

it's been a low Voc month here in the pacific northwest.  About 80 to 90 F this week

[mtdoc]

Not that hot on this side of the Sound. Low 70s here on the North Olympic Peninsula. The few times it hits the 80s here we start seeing people with heatstroke....

[Westbranch]

boB,, Timed out trying to reply      


Mtdoc, would love those 'cool temps

We have heavy smoke from a wild fire ~ 100 miles from us, sun obliterated til 1/2 hr ago...