8
Underload (Dry Well)
The Fhoton™ Drive monitors both the motor load and rotor speed to electronically detect when the pump runs dry. At approximately
35 Hz (rotor speed) and above, the electronic dry well protection algorithm is active. If the motor load falls below the built-in, dry well
trip level while the rotor speed exceeds 35 Hz for a period of 3 seconds, the Fhoton™ drive will halt the motor. The red LED will begin a
1 flash sequence and continue this flash sequence for a duration of 10 minutes. After which time, the drive will resume normal operation
(given the run-command input is still present). See Figure 2: Underload (Dry Well) Protection Algorithm.
Overvoltage
This controller is suitable for use with a DC system delivering not more than 850 V DC maximum. The Fhoton™ Drive monitors the DC input
bus voltage for an over-voltage condition. If the voltage exceeds a predetermined voltage level at any time, the Fhoton™ drive will halt
the motor. The red LED will begin a 2 flash sequence and continue this flash sequence for a duration of 3 cycles. After which time, the drive
will recheck the bus voltage. The voltage must drop back to a safe level before the drive will resume normal operation; otherwise, the red
LED flash sequence will continue.
Locked Rotor
The Fhoton™ Drive monitors both the motor load and rotor speed to electronically detect when the motor/pump is not rotating. If the
motor operates near maximum loading conditions, while the rotor speed is below the minimum operating frequency for a period of
3 seconds, the Fhoton™ drive will halt the motor. The red LED will begin a 3 flash sequence and continue this flash sequence for a duration
of 10 minutes. After which time, the drive will automatically attempt to restart (given the run-command input is still present).
Low Flow Trip
The Fhoton™ Drive monitors the input flow switch to determine whether water is flowing (see Flow Switch under Features). If the flow does
not meet the minimum value to close the switch for a duration of 30 seconds, the Fhoton™ drive will halt the motor. The red LED will begin a
4 flash sequence and continue this flash sequence for a duration of 10 minutes. After which time, the drive will resume normal operation
(given the run-command input is still present).
Figure 2: Underload (Dry Well) Protection Algorithm
Rotor Speed (Hz)
Dry Well
Motor Loading
(%)
Flow Switch Protection
Region For Dry Well
Underload Protection
Region For Dry Well
