Samlex America SCC-30AB - Manuel (Page 21)

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PRINCIPLE OF OPERATION & FEATuREs
SCC-30AB is a Series Type of PWM (Pulse Width Modulation) Solar Charge Controller.
It is based on an advanced design using a micro-controller for digital accuracy and
fully automatic operation. It can be used for 12V or 24V battery systems. PWM battery
charging has been optimized for longer battery life. The unit is designed for user-
friendly operation.
Features
• Advanced microcontroller based, high performance design for digital accuracy and fully
automatic and intelligent operation
• Dual Voltage capability – can be used with 12V / 24V Solar Systems
• 30A charging capacity
• Series Mode PWM (Pulse Width Modulation) charging design at optimum PWM frequency of
300 Hz for low loss, higher efficiency charging and longer battery life
• 4 Stages of charging for 100% return of capacity and long battery life – Bulk, Absorption,
Float and Equalization Stages
• Choice of 8 sets of Absorption / Float / Equalization Voltage settings to enable complete and
safe charging of a wide range of Lead Acid / Ni-Cd Batteries
• Convenient 2 x 16 character LCD Display with backlight for display of operating information
and data. Additional LED indication for displaying the charging stages
• Optional remote Battery Temperature Sensor (BTS) Model DC-BTS-A-C for temperature
compensation to ensure improved charging of batteries that experience wider temperature
variations during the year
• MOSFET based reverse current blocking for night-time battery discharge prevention. This
allows much lower losses as compared to Diode based blocking
• Specially designed for RVs, boats and trucks – allows convenient and aesthetic flush
mounting on walls / panels
Principle of Operation of Solar Charging with Series Type
Pulse Width Modulation (PWM) Control
The design and operation of SCC-30AB is based on Series Type PWM (Pulse Width Modu-
lation) control at PWM frequency of 300 Hz.
PWM Explanation
In order to understand the working of the controller, it is necessary to understand the
concept of PWM and Duty Cycle, which are explained with the help of Fig. 4.0 (page 22).
The explanation is based on Series Type of PWM control
The output of the solar panel is connected to the battery in series with a Switch.
Controlled ON / OFF operation of the Switch is used to control the current and the
voltage to charge the battery.