Projecta SC540
MPPT Solar Charge Controller
12V / 24V / 48V Multi-Chemistry Battery Charging
40A Rated Solar Charge Current
The Projecta SC540 is a 40A MPPT solar charge controller designed to charge 12V, 24V and 48V battery systems from solar panels.
It uses advanced MPPT technology to maximise available solar energy and improve charging efficiency in changing sunlight and temperature conditions.
The SC540 supports GEL, AGM, WET and Lithium battery charging. It includes an LCD display, LED indicators, alarm codes, Bluetooth monitoring support, RS485 communication, external temperature sensor support and dry contact output.
The SC540 is designed for indoor installation only.
The SC540 includes:
5-stage solar charging
Advanced MPPT technology
12V / 24V / 48V battery system support
Automatic battery voltage recognition
40A 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 SC540 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 SC540 supports Lithium battery settings.
For lithium batteries, confirm the battery manufacturer’s recommended charge voltage, current limit and BMS requirements before setup.
The SC540 supports:
12V battery systems
24V battery systems
48V battery systems
The controller automatically recognises the battery system voltage during setup.
The SC540 supports a maximum solar input voltage of less than 100Voc.
Do not exceed the controller’s maximum open-circuit voltage rating.
The SC540 is rated at:
40A solar charge current
The SC540 supports up to:
600W on 12V systems
1200W on 24V systems
2400W on 48V systems
Solar panel sizing must remain within the controller rating.
The SC540 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.
Do not use equalisation unless the battery manufacturer confirms it is suitable.
Yes.
The SC540 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.
Check that:
The sensor is installed on the side of the battery.
The sensor is not close to a heater or external heat source.
The battery is not overheating.
The battery is not faulty.
Ventilation around the battery is suitable.
No.
The SC540 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 must not be operated without a battery voltage reference.
Yes.
Fuses or circuit breakers must be installed on:
Solar input positive circuit
Battery output positive circuit
Cable size depends on current and cable length.
For 40A solar input current, the manual lists examples such as:
Up to 2m: 8AWG / 10mm²
Up to 3m: 6AWG / 16mm²
Up to 5m: 6AWG / 16mm²
For longer runs or higher current applications, confirm cable size based on 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
Daily, monthly, yearly and total charging statistics
The SC540 includes LED indicators for:
PV input
Charging status
Fault status
A warning message means the controller may continue charging.
A fault message means charging has stopped until the issue is corrected.
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 reset.
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 menu includes battery type options such as:
GEL / OPzV
AGM
Lead-Carbon
Flooded
Customise
Traction
OPZS
BMS
The correct option depends on the battery type and system configuration.
The default battery capacity setting is:
200Ah
Battery capacity can be adjusted between:
20Ah and 2000Ah
Reset or confirm the maximum charging current setting after changing battery capacity.
This helps prevent excessive charge current for the connected battery bank.
Yes.
The SC540 supports remote monitoring via Bluetooth.
Bluetooth monitoring can show additional data 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 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 has not been exposed to water or AC voltage.
Check the following:
Solar panels are receiving sunlight.
PV input circuit breaker or fuse is ON.
Solar input polarity is correct.
Solar panel voltage is below 100Voc.
Battery voltage is within supported range.
Battery type is set correctly.
Battery wiring is secure.
No MPPT fault is displayed.
The system is not in Remote OFF / EPO state.
Check:
Solar panel configuration
Panel shading
Panel orientation
PV input wiring
Loose PV terminals
Damaged solar cable
Incorrect series or parallel configuration
Low light or poor weather conditions
Check:
Controller is installed indoors.
Ventilation clearance is maintained.
Controller is not installed in a hot enclosed space.
Maximum current setting is suitable.
Solar input is not oversized.
Ambient temperature is within operating range.
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 SC540 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 the configuration and output of the solar panels.
Fault:
Sampling failure.
Recommended action:
Contact Projecta support or your dealer.
Fault:
Controller memory read/write 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 setting 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 setting.
Warning:
Battery connection to the controller has failed.
Recommended action:
Check the wiring and circuit breaker between the battery and controller.
Warning:
Temperature around the battery temperature sensor is too high.
Recommended action:
Check the sensor is not near a heat source.
If the battery 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 SC540 or SC520 controllers are wired in parallel with Intelli-Grid or Compact systems, each controller must be assigned a unique ID 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 both controllers correctly.
General steps:
Part number: SC540
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: 40A
Maximum solar input power: 600W at 12V / 1200W at 24V / 2400W 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 mounted on a flat, clean surface with suitable ventilation.
Maintain the minimum clearance shown in the manual to ensure normal operation and prevent overheating.
Install the SC540 close to the batteries where practical to reduce voltage drop and improve charging performance.
Before installing or using the SC540:
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 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