Owner`s manual

26 | P a g e
Over Current Protection
The Classic must have over current protection to protect wiring from over current events. A means of
disconnect must be installed on the DC in and DC out of the Classic. Consult your local codes to
determine over current ratings. The breaker between the battery bank and the Classic must conform to
UL489. The breaker between the DC source and the Classic must conform to UL1077 or UL489. The
NEC requires 1.56 times short circuit current for PV over current protection. This is reduced to 1.25
times when using a breaker rated for continuous duty. All MidNite Solar breakers are
hydraulic/magnetic and are rated for continuous duty. No de-rating is required for the output breaker
when using MidNite Solar breakers.
PV in particular will be capable of producing more current than its name plate rating in extreme
situations so the safe minimum wire size should be selected for the PV array maximum short circuit
current. Please consult PV manufacturer for specifications. The US National Electrical Code requires
1.56 times the PV short circuit current for wire size on the PV input. Output wire size follows the NEC
guidelines. Typical wire size for output is 6AWG for the Classic250 and 4AWG for the Classic200 and
150 but check all de-ratings for your wire type and installation method.
Long Distance Wire Runs
The Classic offers some unique opportunities if you are faced with longer than normal wire runs
between the DC source and the Classic. The Classic comes in 3 input voltage ranges letting you design
a DC source at a higher voltage if it is beneficial. For example let’s say you have a 300 ft run from a
PV array to the Classic you could wire for an open circuit voltage close to 250vdc accounting for the
coldest temperature you will encounter. This will allow you to run a smaller gauge wire than with a
lower voltage charge controller. The efficiency of a high voltage Classic is less than the lower voltage
versions, so you need to weigh the benefit. If this sounds too complicated use this rule of thumb in
selecting the proper Classic. PV runs up to 100 feet, use the Classic 150. Runs up to 180 feet, use the
Classic 200. Above 180 feet use the Classic 250.
If the wire size between the DC source and the Classic is larger than the Classic's DC terminal
connector you can use a splicer block or similar connector to reduce down to #4 AWG close to the
Classic. The MidNite E-Panels are supplied with a PV input busbar that accepts up to 2/0 wire.
Connecting the Classic to the Clipper
The connections between the Clipper and Classic are fairly basic. There is the DC – and + conductors
from the Clipper to the PV input on the Classic. There is also a smaller set of – and + conductors
connecting Auxiliary 2 to the PWM input on the Clipper. To program the Classic to work with the
Clipper the Aux 2 needs to be programmed. Follow the steps below to program this. (Note: see our
instructional videos at www.midnitesolar.com)
-Enter the Main menu and scroll to Aux and press Enter.
-Scroll to the right to highlight the text under Aux 2 and press the upper right soft key.
-Scroll up or down to find Clipper control and press the right soft key again
-On this screen we need to select AC or DC for the Clipper you have (DC is default)
-Press the right soft key again and here we need to set the absolute voltage we want the clipper to allow
-Press Enter to save this data and press Main Menu until you get back to the Aux 1 and Aux 2 screen
-Set the Text under Aux 2 to say Clipper Control and press Enter.
-Press Status to return to the home screen.