Specialty Concepts SC3/20 - Manual (Page 9)

15. INSTALL FUSING AS NEEDED: - Add circuit protection where needed. A 20 amp fuse
and disconnect switch should be installed on the Battery (+) run of the SC3/20.
16. RECONNECT BATTERY AND ARRAY POWER
17. CHARGE SET-POINT ADJUSTMENT (RE-CALIBRATION) TO NON-STANDARD SET-
POINTS: - Usually not needed. It is recommended that any adjustment be done by users with
electronic experience. Incorrect settings can lead to the over-charge or undercharge of
batteries or damage to the SC3/20. Access to the rear side of unit is needed and all
adjustments should be performed at times of mild or “room” temperature to insure accurate
settings. Refer to “CHARGE SET-POINT ADJUSTMENT” section below.
18. OPERATION: - Operation of the charge controller is now fully automatic. If the battery voltage
is below the Full Charge Termination set-point (14.3 volts) and power is available from the
array and the Power Connect Sequence (above) was followed, the SC3/20 should start up in
the full-charge mode.
During operation, it is normal for the unit to feel warm.
19. CHECK FOR VOLTAGE DROP (OPTIONAL): - Once the system is installed and operational,
a check on the battery connection is recommended. A poor battery connection will result in a
voltage loss that will cause the batteries to be under-charged and/or result in excessive heat
generated at the location of poor connection (wire connection or terminal block). A voltage
multi-meter is required and the SC3/20 must be charging with maximum expected charge
current.
First, note the voltage at the battery terminals. Select the positive and negative terminals that
are used for the SC3/20 connection. Then note the voltage at the SC3/20 connections for
“BATT (+)” (red) and “BATT (-)” (black). The difference in voltage should be no more than
¼
volt. If the voltage drop is more, suspect crimp connections that have not been soldered or
loose terminals. If no location of voltage drop is found, consider using larger wires for your run
or double-up the number of wires on each run.