Specialty Concepts SC3/20 - Manual (Page 8)

9. RUN SYSTEM WIRING: - After disconnecting the power sources, run the wires from the
battery and solar panel to the location selected for the controller.
WALL MOUNT: Run the array and battery wires into the box through the knockouts, using a
1/2 inch Romex cable clamp for strain relief.
10. NOTE WIRE POLARITY: - Make sure to correctly mark the polarity of the wires using colored
wires or tags. Incorrect polarity may blow the front panel fuse or damage the SC3/20. Some
vehicles or solar kits use black and white wires for connection to the battery. These kits will
label the white wire as battery negative and the black wire as battery positive. Black and red
wiring systems will label the black wire as negative and the red wire as positive. When these
systems interconnect, the black wire does not connect to the black wire. CAREFULLY NOTE
BATTERY POLARITY AND WIRE COLORS!
11. SC3/20 CONNECTION: - Wire the SC3/20 according to Figure 1. When possible, solder the
wires before installing the wire nuts, then wrap the wire nuts and wires with electrical tape.
12. EXTERNAL SHUNT CONNECTION: - If needed.
13. INSTALL TEMPERATURE COMPENSATION (OPTION A): - If included. Refer to OPTIONS
section.
WALL MOUNT: Run the temperature compensation cable through the holes in the knock-out
box.
14. SC3/20 MOUNTING: - Mount the SC3/20 to the wall or box front using the four screws
provided or other suitable fasteners. Slip the washers (supplied) over the screws so the
washers are between the back of SC3/20 and the wall (or box). This provides an air gap for
added cooling. INSTALLATION OF THESE WASHERS IS REQUIRED FOR PROPER
COOLING DURING OPERATION.
EXTERNAL SHUNT FOR 2nd CURRENT READING
The SC3/20 can monitor a current to or from another source, such as a charger or
alternator or for monitoring loads such as a DC source center or an inverter.
The reading is displayed on the fourth position labeled “CURRENT, EXT
SHUNT”. To use this feature, a shunt must be added to system. The shunt value
should be 1 amp per 1 mv for proper reading, for example 100 amp/100 mv. If a
higher current reading than 100 amps is desired, use a 500 amp/50 mv shunt
and remove the Programming Pin Jumper on the back of the digital display
board. The shunt needs to be installed on the negative leg of the subject you are
monitoring. Refer to Figure 3 for wiring instructions for the external shunt and
Figure 4 for location of Decimal Point Programming Pin Jumper.