Timing chart
',
1
3
2
)',
①
Safety-related shutoff
②
Reset ON command required
③
Motor On / Off
Behavior of the failsafe signaling output F‑RQ
In the de-energized condition, the failsafe signaling output F‑RQ is opened. As soon as a main
supply voltage (operational voltage) is applied, the 3RW55 Failsafe soft starter performs a device
test. After a successfully performed test of the switching elements, the failsafe signaling output
F‑RQ closes. If the motor is shut down and the parameterized stopping mode is ended, the
failsafe signaling output F‑RQ is still closed. The 3RW55 Failsafe soft starter performs a device
test. After a successfully performed device test, another starting operation is possible.
The failsafe signaling output F‑RQ signals a device error of the 3RW55 Failsafe soft starter. For
SIL 1 applications, this safety signaling output F‑RQ can be used to display the device state of the
3RW55 Failsafe soft starter. The safety signaling output F‑RQ must be evaluated by a safety relay
or safety control in SIL 3 applications to ensure shutdown of the motor in the error state.
The failsafe signaling output F‑RQ is only opened in the following cases:
• In the de-energized condition
• When a device error occurs (a group error does not influence the state of the failsafe signaling
output F‑RQ)
• During the firmware update of the 3RW55 Failsafe soft starter
• During the Self-test (user-test)
8.15.2
Resetting safety-related shutoff
After a safety-related shutoff, an automatic restart cannot be performed. Depending on the STO
application used, perform the following procedure to restart the motor.
Requirements
• 3RW55 Failsafe soft starter
• Observe the method of operation (Page 212) and the safety instructions in chapter Failsafe
(Page 20).
Functions
8.15 Failsafe
SIRIUS 3RW55 and 3RW55 Failsafe Soft Starters
Equipment Manual, 02/2022, A5E35630887002A/RS-AF/006
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