An autochange is done when the autochange interval has elapsed, the number of running
motors is less than autochange motor limit and the controlling drive is running below
autochange frequency limit.
P3.15.8 BANDWIDTH (ID 1097)
Use this parameter to set the bandwith area around the PID setpoint for starting and
stopping of the auxiliary motors.
When the PID feedback value stays in the bandwith area, the auxiliary motors does not start
or stop. The value of this parameter is given as a percentage of the setpoint.
For example, if setpoint = 5 bar, bandwidth = 10%. When the feedback value stays between
4.5 and 5.5 bar, the motor is not disconnected or removed.
P3.15.9 BANDWIDTH DELAY (ID 1098)
Use this parameter to set the duration before the auxiliary motors start or stop.
When the PID feedback is outside the bandwidth area, the time that is set with this
parameter must elapse befoforeyou can add or remove pumps.
P3.15.10 MOTOR 1 INTERLOCK (ID 426)
Use this parameter to select the digital input signal that is used as interlock signal for the
Multi-Pump system.
10.16.1 OVERPRESSURE SUPERVISION
P3.15.16.1 ENABLE OVERPRESSURE SUPERVISION (ID 1698)
Use this parameter to enable the Overpressure supervision.
If the PID feedback becomes higher than the set overpressure limit, all auxiliary motors
stops immediately. Only the regulating motor continues to operate.
You can use the Overpressure supervision function in a Multi-pump system. For example,
when you close the primary valve of the pump system quickly, the pressure in the pipe lines
increases. The pressure can increase too quickly for the PID controller. To prevent that the
pipes break, the overpressure supervision stops the auxiliary motors in the Multi-pump
system.
The overpressure supervision monitors the feedback signal of the PID controller, that is, the
pressure. If the signal becomes higher than the overpressure level, it stops all the auxiliary
pumps immediately. Only the regulating motor continues to operate. When the pressure
decreases, the system continues to operate, and connects the auxiliary motors again one at a
time.
PARAMETER DESCRIPTIONS
VACON · 315
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