A Forum run by Enthusiasts of MidNite Solar

General Category => General FAQ'S => Topic started by: 73-GMC-RV on April 04, 2018, 03:32:10 PM

Title: Display readout for Volts
Post by: 73-GMC-RV on April 04, 2018, 03:32:10 PM
When I turn on my Midnight I get these readings on the Volts IN

56.6

then when the unit is booted up completely is show only

31.7v

What is the differences in these 2 numbers.  I have 6 100 watt panels   2 strings of 3 panels.

Title: Re: Display readout for Volts
Post by: Vic on April 04, 2018, 04:02:00 PM
Hi .. GMC..,

The first number, 56.6,  is the PV Voc (Open Circuit Voltage),   because the Classic has not placed any load on them.

The second number,  31.7,   is the PV Vmp (Maximum Powerpoint Voltage.   This is lower than the first,   as the Classic is drawing current from them.

These two numbers will be different than the PV Ratings for Voc  and Vmp,   as there are temperature effects,   changes in illumination,   etc,   based upon the sun angle,   clouds  ...   moisture in the air,   etc,   compared to the Standard Test Conditions used for Rating PV output.

Vic
Title: Re: Display readout for Volts
Post by: 73-GMC-RV on April 13, 2018, 03:51:41 PM
Thanks for the reply... I am new full time resident in my RV.

http://midniteftp.com/forum/index.php?topic=4033.0

Does this numbers look correct for the panels I have installed.

Wondering if the unit and array were performing as expected with the numbers I entered from the panels and todays time of year here in CA.

Sun is getting higher in the sky, these are flat mounted on my RV roof.