Samlex Solar SCW-20-2 Owner's Manual

The Samlex Solar SCW-20-2 is a 20 Amp MPPT Solar Charge Controller designed for 12V/24V battery systems. It features Maximum Power Point Tracking (MPPT) technology for optimal solar energy harvest, comprehensive battery protection (overcharge, deep discharge, short circuit), LCD display for system monitoring, configurable charging parameters, and temperature compensation. Suitable for off-grid solar applications like RVs, boats, cabins, and backup power. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Operation Modes 8. Protection Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: MPPT charge controller unit, LCD display, Terminal blocks (PV, Battery, Load), Temperature sensor port, USB communication port (optional).

Feature	Description
MPPT Technology	Maximizes solar panel power output
Battery Voltage	Auto-detects 12V or 24V system
LCD Display	Shows PV voltage, battery voltage, charging current, load status
Temperature Compensation	Adjusts charging voltage based on battery temperature
Load Control	Programmable DC load output with timer function
Protections	Overcharge, deep discharge, reverse polarity, short circuit
Communication	Optional USB port for data monitoring
Mounting	Wall or DIN rail mountable
Operating Temp	-20°C to +50°C
Max PV Input	100V DC, 20A charging current

Installation

Unpack and inspect contents. Mount in a dry, well-ventilated location.

Connect Battery: First, connect battery terminals (BAT+ and BAT-) to controller using proper gauge wires.
Connect Solar Panel: Connect PV panel wires to PV+ and PV- terminals.
Connect Load: Connect DC load wires to LOAD+ and LOAD- terminals if used.
Connect Temperature Sensor: Plug sensor into port for accurate temperature compensation.
Power On: The controller will auto-detect battery voltage and start operation.

WARNING! Always connect battery first, then solar panel. Disconnect in reverse order. Ensure correct polarity to avoid damage.

First-Time Setup

After installation, configure settings for your battery type.

Select Battery Type: Use buttons to navigate menu. Choose from Sealed, Gel, Flooded, or User-Defined.
Set Charging Parameters: Adjust bulk/absorption voltage, float voltage, and equalization if applicable.
Configure Load Control: Set load output mode (Manual, On/Off with timer, or Voltage control).
Set System Voltage: Verify auto-detected voltage (12V/24V) is correct.
Save Settings: Confirm and save. The LCD will display real-time charging data.

CAUTION! Use appropriate personal protective equipment when working with batteries. Avoid sparks near battery.

Specifications

Model: SCW-20-2
Rated Charge Current: 20A
Max PV Input Power: 260W @ 12V, 520W @ 24V
Max PV Open Circuit Voltage: 100V DC
Battery Voltage: 12V / 24V Auto
MPPT Tracking Efficiency: >99%
Overall Efficiency: Up to 98%
Load Output Current: 20A Max
Communication: Optional USB (Adapter not included)
Operating Temperature: -20°C to +50°C
Protection: IP30 (Indoor use)
Dimensions: Refer to product label

Controls and Settings

Access menu via button on front panel. LCD Display shows: PV Voltage (Vpv), Battery Voltage (Vbat), Charging Current (Ibat), Load Status, Error Codes.

Buttons: MENU, UP, DOWN, ENTER.

Menu Structure: BATTERY TYPE (Sealed, Gel, Flooded, User), CHARGE SET (Bulk, Float, Equalize voltages), LOAD SET (Mode, Timer, Low Volt Disconnect), SYSTEM (Language, Reset, Info).

Default password for advanced settings: 0000.

Connecting Devices

Battery: Use BAT+ and BAT- terminals. Solar Panel: PV+ and PV- terminals. Load: LOAD+ and LOAD- terminals.

Ensure all power sources are off before connecting.
Use correct wire size (min. 10 AWG for 20A).
Secure connections tightly to prevent arcing.
Install appropriate fuses on battery and PV positive lines.

Tip: Keep wiring runs as short as possible to minimize voltage drop.

Operation Modes

MPPT Charging: Continuously tracks max power point of solar array.

Bulk Charging: Constant current until battery reaches absorption voltage.
Absorption Charging: Constant voltage to fully charge battery.
Float Charging: Maintains battery at full charge with reduced voltage.
Equalization (Flooded batteries only): Periodic overcharge to balance cells.
Load Management: DC output can be controlled manually, by timer, or by battery voltage.

WARNING! Do not disconnect battery while solar panel is connected and producing power.

Protection Features

Battery Overcharge Protection: Stops charging when voltage exceeds set limit. Battery Deep Discharge Protection: Disconnects load when battery voltage is too low (adjustable). Reverse Polarity Protection: On PV and battery terminals. Short Circuit Protection: On load and PV terminals. Over Temperature Protection: Reduces charge current if controller overheats.

Care & Maintenance

Periodically check terminal connections for tightness and corrosion. Keep controller clean and free of dust. Ensure ventilation is not blocked.

CAUTION! Disconnect all power sources before performing any maintenance. Do not use compressed air or liquids for cleaning.

Regulatory Information

Complies with relevant safety and EMC standards for electronic equipment. This device is intended for indoor use in dry locations. Copyright © Samlex Solar. All trademarks are property of their respective owners. For technical support and warranty information, visit www.samlexsolar.com or contact [email protected].

Troubleshooting

Symptom	Possible Cause	Corrective Action
No display / Not powering on	No battery connection / Low battery	Check battery connections and voltage (min. 9V for 12V system).
Not charging	PV connection / Shading / Fault	Check PV wiring and polarity. Ensure panels are in sunlight. Check for error codes.
Load output not working	Settings / Low battery / Protection triggered	Check load control settings. Check battery voltage. Reset controller.
Error code on display	Various faults	Refer to manual error code list (e.g., E01: Battery overvoltage).
Low charging current	Panel mismatch / Poor sun / High temp	Check PV voltage is within range. Clean panels. Ensure controller is cool.

Reset: Menu > System > Factory Reset (use caution).

Service: Do not open unit. Contact authorized service center. www.samlexsolar.com