Siemens SINAMICS V20 Operating Manual page 12

Pump switch-in/switch-out
Pump switch-out
If the pump controlled by the inverter runs at a speed lower than the frequency switch-out
threshold (P4014 + P1080) and the PID error is lower than the PID error switch-out threshold
(-P2373) for specified time (P2375), the inverter first switches off the pump (OFF2) which
runs in inverter operation, and then captures a running pump and switches it from line
system operation to inverter operation. Parameter P4012 is used to control the selection
mode for switching in/out motors.
● P4012 = 0: Selecting the next pump according to the fixed sequence. The inverter
switches out the pump by following the sequence M4, M3, M2, to M1.
● P4012 = 1: Selecting the next pump according to the operating hours. The inverter first
switches out the pump with the most absolute operating hours (r4026 to r4029).
Note
If the PID error drops below the switch-out delay override (-P2376), the inverter skips the
switch-out delay (P2375) and performs the switch-out operation immediately.
12
SINAMICS V20 multi-pump control
Operating Manual, 05/2018, A5E43416874-002