Parameters
Description
Stopping time
The stopping time defines the time within which the motor voltage is reduced
from line voltage to 0 V.
It may take longer for the motor to actually coast down to a standstill.
The setting "0 s" causes the motor to be shut down immediately without a
down ramp.
• Factory setting: 10 s
• Setting range: 0 ... 360 s
• In steps of: 0.1 s
Stopping torque
The motor torque is "controlled" until the stopping torque is reached and then
switched off. The rated torque of the motor is used as the reference value.
• Factory setting: 10%
• Setting range: 10 ... 100%
• In steps of: 5%
8.2.5
Pump stop
Operating principle
With a torque-controlled pump stopping mode, stopping of the pump is prolonged. This
stopping mode is set if there is a need to prevent the pump from being stopped abruptly.
Due to the very low moment of inertia that always applies in pumps, the pump operating
mechanism (motor) can come to a standstill suddenly when shutting down, due to the counter-
pressure of fluid in the piping system. This can result in pressure fluctuations in the pipe system
which in turn cause loud noises (water hammer) and mechanical problems, e.g. to return valves.
For this reason, the flow rate of the pump is reduced gradually during pump stopping mode. In
the case of smaller pumps this effect can often be ignored.
Application
• Drives for which the abrupt stopping of the pump is to be prevented.
Setting via 3RW5 HMI High Feature
• Menu: "Parameters > Soft Starter > Parameter set 1 / 2 / 3 > Stopping mode settings >
Stopping mode > Pump stopping mode"
• Menu (Parameters): "Parameters > Soft Starter > Parameter set 1 / 2 / 3 > Stopping mode
settings"
Functions
8.2 Run-down
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
152
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
