DIY Manual

53 | P a g e 10-543-1 REV A
DIY Manual
Legacy P&O (Perturb and Observe) – To “perturb” means to change. In this mode, the Classic will
intentionally change or move away from the first found Vmp, measure the reduction or increase
in power out, then sweep again to lock on to either a higher or lower Vmp (relative to the first
found Vmp), always seeking the best Vmp for maximum power production. Legacy P&O has a
slower sweep and is useful when mismatched PV is installed, which means two different Vmp
points. User-selectable set points include the interval between sweeps in minutes and the sweep
depth as a % of change in watts.
Dynamic – Similar to Solar Mode, tracks change in power on the fly. Dynamic MPPT uses the
voltage dip on the solar panel multiplied by the increasing current every switching cycle to
determine the error signal that will be produced to regulate the duty cycle. The dynamic response
detects the slope of the IV curve, creating a power ramp from which the error signal intersects
creating a power representative duty cycle.
U-Set Voc – Manual mode based on a percentage of
Voc. The Classic will sweep based on the user-set time
in minutes and then lock on to the voltage as
determined by the pre-set. Useful for testing or
different hydro or DC inputs.
TROUBLESHOOTING
Classic Makes No Power: Resting
Does your MNGP show the Classic is Resting? Resting means the Classic is not in Bulk, Absorb,
Float, or Equalization charging modes; basically, the Classic is waiting to be called upon to make
power. If the PV input is absent or the PV voltage is too low, the Classic will remain in Resting.
Check that the Mode is ON. Go to the Mode menu and make sure it is in Solar and ON. If not,
set both and press Enter to save. If the Mode is OFF, the MNGP will display “Mode is OFF” vice
“RESTING,” but the Classic will act like it is resting.
Check the Reason for Resting. From the 1
st
Status page, hold the left arrow and tap Enter. The
number between IN and BATT, top center, is the Reason for Resting code. After performing the
troubleshooting suggestions below with no success, call MidNite’s Tech Support with that RFR
code for further assistance.
Change the Mode to Legacy P&O to see if this brings the Classic out of Resting.
DO NOT connect an engine-driven DC generator to the Classic! These will almost always
be a constant voltage DC source, which will cause harm to the Classic and void the
warranty.
Mode must be manually turned ON
after changing the mode.