Operating Instructions

Siemens Industry, Inc. • 90 Siemens Application
24-hour support [phone] (Dial 2)
MULTI-PUMP USE
Motors are connected/disconnected if the PID controller is not able to keep the process value or feed-
back within the defined bandwidth around the setpoint.
Criteria for connecting/adding motors (also see Figure 35):
• Feedback value outside the bandwidth area.
• Regulating motor running at a “close-to-max” frequency (-2Hz).
• Conditions above are fulfilled for a time longer than the bandwidth delay.
• There are additional motors available.
Figure 35.
Criteria for disconnecting/removing motors:
• Feedback value outside bandwidth area.
• Regulating motor running at a “close-to-min” frequency (+2 Hz).
• Conditions above are fulfilled for a time longer than the bandwidth delay
• There are more motors running than the regulating one.
Interlock function (P3.14.2)
Interlocks can be used to tell the Multi Pump system that a motor is not available, e.g. because the motor
is removed from the system for maintenance or bypassed for manual control.
Enable this function to use the interlocks. Choose the needed status for each motor by digital inputs (pa-
rameters P3.5.1.25 to P3.5.1.28). If the input is closed (TRUE) the motor is available for the Multi Pump
system, otherwise it will not be connected by the Multi Pump logic.
EIN
AUS
EIN
AUS
11111.emf
Motor 2
Motor 3
Del ay
Bandwidth
Feedback
Set poi nt
Drive is running at maximum
or close to maximum frequency