38.4 volts draw at night from the classic 150 while at rest.

[sirmoiu]

Hello guys,
        i have a problem, at night when everything is in rest mode, on my classic 150 it says that 38.4 volts coming from my panels, when i isolate the panels and check it with my volt meter , the classic is reading the the 38.4 volts and the panels drops down 3 volts or less, is it normal for the classic to have that amount of volts on it, without anything coming in.

[ClassicCrazy]

yes normal for the Classic to show some voltage at night . Right now in the dark one of mine is showing 7 volts and the other one is showing 11 volts.  I think it has something to do with the classic getting enough power from the batteries at night to keep running.

Although if yours is reading 38.4 volts at night that does seem kind of high.  Does your pv go directly to Classic input without any other wiring connections along the way ?

Larry

[sirmoiu]

Hello Larry,
My panels goes thru a 40 amp breaker then to the classic.

[ClassicCrazy]

What is battery voltage does your system use ?

Take a look at this post - as you can see this question gets asked often.
http://midniteftp.com/forum/index.php?topic=3914.0

Larry

[Vic]

YES,   this apparent input voltage to the Classic CCs is normal.

The Classic injects a small current at the input,   sometimes called a "precharge" .

Often  the more PV strings that the Classic has on its input,  the lower will be this  voltage reading (probably due to reverse current from each string of PVs).

Am no expert on this,   FWIW,   Vic

[sirmoiu]

my battery system is 48 volts,
thanks guys for the help.