• When the start signal is turned OFF during operation, the inverter-driven motor is decelerated to stop. The motors under
commercial power supply operation are switched over to inverter-driven operation one at a time and decelerated to stop after
frequency search in order from the longest operation time.
• When a protective function is activated while running, MC (RO1 to RO4) turns OFF and the inverter output is shut off.
• When the MRS signal is turned ON during operation, the inverter output is shut off and the running motors coast to a stop.
Although the motor with the longest operating time of the commercial power supply operation is switched to the inverter
operation after elapse of time set in Pr.591 Auxiliary motor stop detection time, the output shutoff status remains. When
the MRS signal is turned OFF, the inverter-driven operation starts after frequency search. When the MRS signal is turned OFF,
the inverter-driven operation starts after frequency search.
• If the starting signal is turned ON during deceleration regardless of the Pr.579 setting, the multi-pump operation is performed
PID overpressure control (Pr.1370 and Pr.1376)
• When the main valve is suddenly closed in the multi-pump function system, a sudden increase of the pipe pressure may
occur, and the pipes may be broken. To prevent fracture of the pipes, all auxiliary motors are stopped when the feedback
value exceeds the predetermined level.
• When the PID measured value reaches or exceeds the Pr.1376 Auxiliary motor stopping level and the elapsed time
exceeds the Pr.1370 Detection time for PID limiting operation while the multi-pump function is activated, all operating
auxiliary motors are disconnected and allowed to coast to a stop regardless of the Pr.579 Motor connection function
selection setting. The motor driven by the inverter continues its operation.
• After the auxiliary motor is stopped, the motor operation does not start while the PID measured value is equal to Pr.1376
setting or more even when the auxiliary motor starting condition is satisfied.
• The PID overpressure control function can be used when PID control is performed (reverse action only) by the set point and
measured value input using the multi-pump function.
• Either the first or the second PID measured value is used according to the PID control selection. When the control switches
between the first PID control and second PID control, the measured value to be used is also switched to continue the control
Parameters referred to
Pr.20 Acceleration/deceleration reference frequency, Pr.21 Acceleration/deceleration time
Pr.57 Restart coasting time, Pr.58 Restart cushion
Pr.178 to Pr.189 (Input terminal function
Pr.190 to Pr.196 (Output terminal function
5.11 (A) Application parameters