Protection Features; How It Works - Franklin Electric SubDrive Solar Manuel D'installation

Protection Features

Electronic monitoring gives the controller the capability to monitor the system and automatically shut
down in the event of:
• Dry well conditions – with smart pump monitoring
• Bound pump – with auto-reversing torque
• High voltage surge
• Low input voltage
• Open motor circuit
• Short circuit
• Over heat
• Deadhead/no flow conditions
NOTE: This drive provides motor overload protection by preventing motor current from exceeding
SFA and by limiting the duty cycle in the event of no water flow. This drive does not provide over-
temperature sensing of the motor.

How it Works

The SubDrive Solar system serves to provide water in remote applications where electrical grid power
is either unreliable or unavailable. The system pumps water using a high-voltage DC power source
such as an array of solar panels. Since the sun is only available during certain hours of the day and
only in good weather conditions, the water is generally pumped into a storage tank. Two level
switches can be installed inside the tank to regulate the water level. A flow switch detects if flow is
below critical levels while the pump is still running. This serves as an indication that the well has run
dry, or that insufficient power is available to continue pumping. The system will shut down to protect
the pump and motor until the well, or adequate electric power, has recovered.
The SubDrive Solar controller runs at variable speed to match the changing power available from
the PV solar array. Variable speed operation means there is no in-rush or surge of energy during the
pump/motor start-up, helping to eliminate wear on the motor and pumping system. A leading cause
of pump motor failure is the stress applied to the motor during a full voltage start-up. The SubDrive
Solar variable speed operation ramps up the speed smoothly, which eliminates starting stress. This
feature enhances long-term motor reliability (pg. 8).
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