3 4
7. Protection
Battery Over Voltage Protection
When the battery voltage reaches to the set point of Over Voltage
Disconnect Voltage(OVD), the controller will stop charging the battery to
protect the battery from being over charged to break down.
Battery Over Discharge Protection
When the battery voltage reaches to the set point of Low Voltage
Disconnect Voltage(LVD), the controller will stop discharging the battery to
protect the battery from being over discharged.
Load Overload Protection
Load will be switched off when 1.25 times rated current overload happens.
User has to reduce load appliance, then press the button or repower the
controller.
Load Short Circuit Protection
Load will be switched off when load short circuit (≥3 times rated current)
happens. User has to clear short circuit, then press the button or repower
the controller.
High Voltage Transients Protection
The controller is protected against small high voltage transients. In lightning
prone areas, additional external suppression is recommended.
8. Troubleshooting
LED Charging
indicator turn off
during daytime
when sunshine falls
on PV modules
properly
Confirm that PV and battery
wire connections are correct
and tight
Battery voltage
maybe less than 8V
Measure battery voltage with
the multi-meter. Min.8V can
start up the controller
Charging status
LED indicator Fast
flashing
Check if battery voltage is
higher than OVD, and
disconnect the PV
When the battery voltage is
restored to or above LVR point
(low voltage reconnect
voltage), the load will recover
Load status LED
indicator slowly
flashing
①Please reduce the number of
electric equipments .
②Press the button or repower
the controller.
Load status LED
indicator fast
flashing
①Check carefully loads
connection, clear the fault.
②Press the button or repower
the controller.
①When load current reaches1.25 times 1.5 times and 2 times 1.35-1.5 times
more than nominal value, the controller will automatically turn off loads in 60s,
5s and 1s respectively.
9. Technical Specifications
Battery input voltage range
Max. PV open circuit voltage
Charge Circuit Voltage Drop
Discharge Circuit Voltage Drop
Temperature compensation
coefficient
Working environment
temperature
Battery Voltage Control Parameters
Below parameters are in 12V system at 25 ºC, please double the values in
24V system
Over Voltage Disconnect Voltage
Over Voltage Reconnect Voltage
Equalize Charging Voltage
Boost Reconnect Charging Voltage
Low Voltage Reconnect Voltage
Under Voltage Warning Reconnect
Voltage
Under Voltage Warning Voltage
Low Voltage Disconnect Voltage
Discharging Limit Voltage
10. Disclaimer
This warranty does not apply under the following conditions:
Damage from improper use or use in an unsuitable environment.
PV or load current, voltage or power exceeding the rated value of controller.
User disassembly or attempted repair the controller without permission.
The controller is damaged due to natural elements such as lighting.
The controller is damaged during transportation and shipment.
11. Package Contents
MP-3750 / MP-3752 charge controller
User manual
Distributed by:
TechBrands by Electus Distribution Pty. Ltd.
320 Victoria Rd, Rydalmere
NSW 2116 Australia
Ph: 1300 738 555
Int’l: +61 2 8832 3200
Fax: 1300 738 500
www.techbrands.com
Made in China
Any changes without prior notice! Version number:V1.8