Classic Manual Revision 22Jan2021 Final

For help with the Classic or Classic SL, please see our how-to videos and extended documentation at
www.midnitesolar.com/documentIndex.php . Before calling Tech Support, we recommend visiting
this website for some of the most common issues.
WARNING: Arc Fault protection is not ON by default.
NOTE: The National Electrical Code Article 690.11 requires Arc Fault protection. The Classic has
this built-in as standard equipment and will need to be enabled, if so desired. The Classic SL does
not have Arc Fault built-in.
NOTE: The Arc Fault protection has adjustable sensitivity and may require some tuning for your
particular system to avoid nuisance tripping. Some house loads like table saws and well pumps and
other motor loads can be seen on the PV circuit in the Classic appearing similar to DC arcs. We have
started with a general average we have found to work reliably but in some cases this sensitivity
level is too high causing false Arc Fault alarms. When the Classic goes into Arc Fault, it goes to
Resting and will not charge the batteries. Please consult the Classic Manual for enabling and fine-
tuning of the Arc Fault system.
DANGER OF DEATH TO YOUR CLASSIC!
When the Classic is used with wind or hydro, a Clipper-type device will most likely be needed to
protect against over-voltage. A battery-based diversion load WILL NOT keep the Classic safe from
over-voltage. High input voltage is recorded and over-voltage is not covered under warranty.
Never wire a pump or other load to the input side of the Classic. If a load must be wired to the input
side of the Classic, the load and Classic need to have blocking diodes on them.
Never parallel two Classics onto one PV array.
For larger systems with large inverters and or multiple inverters (i.e., Radian or XW+), it is
important to use appropriately sized cables and bus bars or damage to the inverters or charge
controllers can occur. Take a single XW+ E-Panel, for example, it has a positive bus bar for the
charge controller battery side connections. This bus bar is sufficient for two charge controllers; if
you need three or more, then you need to look at the best way to handle the amperage. A dual
Radian, for example, is actually four separate inverters. Properly sized cables as well as a large
enough battery bank is very important. Most manufacturers of battery-based inverters recommend
100Ah of battery per kW of solar modules. Please consult the inverter manufacturer for assistance
with cable sizing.
Classic SL
This Owner’s Manual covers both the Classic and the Classic SL models.
The Classic SL performs the same functions as the regular Classic, but WITHOUT the following
features: 1) No Arc Fault circuit; 2) No AUTO EQ function; 3) No Ethernet port; 4) No wind or hydro
programming; and 5) The Classic SL does not include the Battery Temp Sensor, sold separately.