Projecta SC520
MPPT Solar Charge Controller
12V / 24V / 48V Multi-Chemistry Battery Charging
20A Rated Solar Charge Current
The Projecta SC520 is a 20A MPPT solar charge controller designed to charge 12V, 24V and 48V battery systems from solar panels.
It uses advanced MPPT, Maximum Power Point Tracking, technology to improve solar charging efficiency in different sunlight, weather and temperature conditions.
The SC520 supports multiple battery chemistry types including GEL, AGM, WET and Lithium. It also includes automatic battery system voltage recognition, LCD display, LED status indicators, alarm codes, RS485 communication and Bluetooth monitoring support.
The SC520 is designed for indoor installation only.
The SC520 includes:
5-stage solar charging
Advanced MPPT technology
12V / 24V / 48V battery system support
Automatic battery voltage recognition
20A rated solar charge current
Multi-chemistry battery selection
GEL, AGM, WET and Lithium support
LCD display screen
PV, Charge and Fault LED indicators
RS485 communication port
Bluetooth monitoring support
External battery temperature sensor port
Dry contact output
EPO / Remote OFF contact port
Reverse polarity protection
Over-voltage protection
Over-temperature protection
Night-time battery discharge protection
Negative grounded system design
The SC520 supports multiple battery chemistry types, including:
GEL
AGM
WET / Flooded
Lithium
Custom battery settings
The selected battery type must match the battery manufacturer’s charging requirements.
Yes.
The SC520 supports Lithium battery settings.
For lithium batteries, always confirm the required charging voltage, current limit and battery management system requirements before setting up the controller.
The SC520 supports:
12V battery systems
24V battery systems
48V battery systems
The controller automatically recognises the battery system voltage during setup.
The SC520 supports a maximum solar input voltage of less than 100Voc.
Do not exceed the maximum open-circuit voltage rating of the controller.
The SC520 is rated at:
20A solar charge current
The SC520 supports up to:
400W on 12V systems
600W on 24V systems
1200W on 48V systems
Solar panel sizing must remain within the controller rating.
The SC520 uses a 5-stage charging process:
Soft Start — Delivers half rated current until the battery voltage rises above the required level or until timeout.
Bulk / Boost Charge — Uses MPPT to deliver maximum available charging current until the battery reaches absorption voltage.
Equalisation — Applies only to supported lead acid battery types such as Flooded, WET and AGM, depending on settings.
Absorption — Holds a constant voltage until charge current drops below the set threshold.
Float — Maintains the battery at a safe voltage once fully charged.
Recycle Charge — After extended float charging, the controller returns to bulk charging to refresh the battery.
Yes, but only for compatible lead acid battery types where equalisation is supported.
Equalisation should not be used on batteries that do not allow it, including many sealed and lithium batteries.
Always follow the battery manufacturer’s recommendations.
Yes.
The SC520 has a port for an optional external battery temperature sensor.
When fitted, the controller can optimise charging based on battery temperature.
Temperature compensation is for lead acid batteries only.
The temperature sensor should be placed on the side of the battery.
Do not place the sensor near an external heat source, as this can cause incorrect temperature readings.
No.
The SC520 is designed for indoor use only.
Do not expose the controller to rain, snow or liquids.
Follow this wiring sequence:
To power off or service the system:
The controller is not designed to run without a battery voltage reference.
The controller requires a battery voltage reference.
If the battery is removed while solar input remains connected, the controller may operate incorrectly or be damaged.
Always disconnect or cover solar panels before servicing or replacing the battery.
Yes.
The manual states that fuses or circuit breakers should be installed on:
Solar input positive circuit
Battery output positive circuit
Cable size depends on current and cable length.
For 20A solar input current, the manual lists examples such as:
Up to 2m: 10AWG / 6mm²
Up to 3m: 10AWG / 6mm²
Up to 5m: 8AWG / 10mm²
Up to 7m: 6AWG / 16mm²
Always size cable to suit current, distance, voltage drop and installation standards.
The LCD display can show:
Battery voltage
Charging current
Solar input voltage
Output power
Working status
Warnings
Faults
System information
Charging statistics
The SC520 includes LED indicators for:
PV input
Charging status
Fault status
If a fault occurs, the display will show an MPPT error code.
If a warning occurs, the controller may continue charging while showing a warning message.
The front panel buttons are used for:
Cancel / return
Previous page / increase value
Next page / decrease value
Enter / select / confirm
The controller enters the Setup Wizard when first powered on or after factory settings are restored.
The Setup Wizard allows the user to set:
Time and date
Battery type
Battery capacity
Confirmation of settings
The manual states the initial password for parameter setting is:
1000
The password can be changed in the Factory Set interface.
The menu includes battery type options such as:
GEL / OPzV
AGM
Lead-Carbon
Flooded
Customise
Traction
OPZS
BMS
The correct setting depends on the battery type and system configuration.
The default battery capacity setting is:
200Ah
Battery capacity can be adjusted between:
20Ah and 2000Ah
The maximum charging current setting should be reset whenever the battery capacity is changed.
This helps ensure the charge current remains suitable for the battery bank.
Yes.
The SC520 supports remote display via Bluetooth.
Bluetooth monitoring can show additional parameters such as:
Charging watt-hours
Charging current
Solar input voltage
System status
Yes.
The controller includes an RS485 communication port.
Check the following:
Battery is connected correctly.
Battery voltage is within the supported range.
Battery fuse or circuit breaker is ON.
Battery polarity is correct.
Battery terminals are tight.
Solar input was not connected before the battery.
Controller wiring cover is installed correctly.
Check the following:
Solar panels are receiving sunlight.
Solar panels are not fully covered or shaded.
PV input circuit breaker or fuse is ON.
Solar polarity is correct.
Battery voltage is within range.
Battery type setting is correct.
No MPPT fault is displayed.
Solar input voltage is below 100Voc.
Battery wiring is secure.
Yes.
The manual separates alarms into two levels:
Warning — Controller continues charging normally while displaying a warning.
Fault — Controller stops charging due to an error condition.
Check the warning code and correct the cause if required.
Check:
Battery type setting
Battery system voltage setting
Absorption voltage setting
Float voltage setting
Whether external voltage is being applied to the battery
Whether the battery is configured as 12V, 24V or 48V correctly
Check the wiring and circuit breaker between the battery and controller.
Confirm that the battery positive and negative cables are connected securely and with correct polarity.
Fault:
Solar input voltage has exceeded the controller’s maximum rating.
Recommended action:
Lower the total solar panel voltage connected to the controller.
Fault:
Battery output voltage has exceeded the controller’s maximum rating.
Recommended action:
Check whether external voltage is being applied to the battery.
Check that the SC520 battery setting matches the battery configuration.
Fault:
Battery short circuit.
Recommended action:
Check and correct the battery wiring.
Fault:
Bulk stage charging current has exceeded the controller’s maximum rating.
Recommended action:
Lower the maximum charging current setting in:
Parameter Set
Para_Battery
Advanced Set
CHG_MAX_Current
Fault:
Controller has exceeded the ambient temperature limit.
Recommended action:
Ensure the controller is installed in a well-ventilated area.
Fault:
Solar panel power is too low.
Recommended action:
Check solar panel configuration, sunlight condition, wiring and panel output.
Fault:
Sampling failure.
Recommended action:
Contact Projecta support or your dealer.
Fault:
Controller read/write memory function is abnormal.
Recommended action:
Contact Projecta support or your dealer.
Fault:
The 2-pin EPO terminal is not connected to the controller EPO.
Recommended action:
Insert the 2-pin phoenix terminal into the EPO port.
If the fault remains, contact Projecta support.
Warning:
Battery voltage has exceeded the maximum rating.
Recommended action:
Adjust the battery parameter settings to match the battery configuration.
Warning:
Battery voltage is too low.
Recommended action:
Check the battery configuration and allow the battery to charge back to normal voltage range.
Warning:
Charging current has exceeded the maximum rating.
Recommended action:
Check the battery parameter settings.
Warning:
Battery connection to the controller has failed.
Recommended action:
Check battery wiring and circuit breaker between the battery and controller.
Warning:
Temperature around the battery temperature sensor is too high.
Recommended action:
Check that the sensor is not near a heat source.
If the battery itself is hot, the battery may be faulty.
Warning:
Controller model setting does not match the controller configuration.
Recommended action:
Check and adjust the model setting.
Warning:
Internal temperature sensor board fault.
Recommended action:
Contact Projecta support or your dealer.
Yes.
When multiple SC520 or SC540 controllers are wired in parallel with Intelli-Grid or Compact systems, each solar controller must have a unique address.
Set the first controller as:
SYS_Module_Addr = 1
Set the second controller as:
SYS_Module_Addr = 2
This allows the system to identify each controller correctly.
General steps:
Part number: SC520
System wiring: Negative grounded
Battery system voltage: 12V / 24V / 48V DC
No-load loss: 1mA at 12V / 3mA at 24V / 5mA at 48V
Maximum solar input voltage: Less than 100Voc
Rated solar charge current: 20A
Maximum solar input power: 400W at 12V / 600W at 24V / 1200W at 48V
Operating temperature: -40°C to +70°C
Net weight: 1.4kg
Communication: RS485, Bluetooth
Dimensions: 205 x 160 x 68.5mm
Dry contact: 30VDC / 2A
IP rating: IP31
Battery and solar terminal screw tightness: 1.2Nm
The controller should be installed on a flat, clean surface with suitable ventilation.
Minimum clearance should be maintained around the controller to avoid overheating.
Install the SC520 as close to the batteries as practical to reduce voltage drop and improve charging performance.
Before installing or using the SC520:
Read the manual before installation.
Do not expose the controller to rain, snow or liquids.
Do not connect AC sources to the controller.
Confirm battery polarity before connection.
Cover solar panels before wiring.
Install suitable fuses or circuit breakers.
Use correct cable size for the current and distance.
Keep sparks and flames away from lead acid batteries.
Wear suitable insulated protection when wiring.
Keep the controller out of reach of children.
Disconnect solar input before battery servicing.
Escalate the case if:
The controller repeatedly shows a fault code after wiring checks.
Solar input voltage has exceeded controller rating.
Battery wiring or polarity damage is suspected.
The controller has been exposed to water.
AC voltage has been connected accidentally.
The controller overheats repeatedly.
Fault 11, Fault 12, Fault 13 or Warning 14 remains active.
Bluetooth or RS485 communication does not work after setup checks.
Parallel controller addressing cannot be configured.
Warranty assessment is required.