Emergency Stop System; Emergency Stop Safety Features - nVent SCHROFF Rack Safety Plus 3 U User Manual

3. Emergency Stop System

The device is equipped with an emergency stop
button (6).
Pressing the emergency stop button disconnects
the switched AC and DC outputs from the mains.
The button is mechanically latching. Emergency
stop is deactivated by pulling the button.
The switched AC and DC outputs can be turned on
again by pressing the Outputs ON button.
Danger of electric shock
The "Service" AC outputs are not switched off via the Emergency Stop
System.
3.1

Emergency Stop safety features

The Emergency Stop function of the nVent SCHROFF power distribution unit is controlled
and monitored by a safety relay.
The safety relay provides a safety-related interruption of the switched outputs. The safety
relay meets the requirements of EN 60947-5-1 and EN 60204-1 in applications with E-STOP
push buttons.
The emergency stop push button is vandalism-proof. If the emergency stop is sheared off
during operation, the emergency stop function is also triggered.
The safety relay meets the following safety requirements:
•
The circuit is redundant with built-in self-monitoring.
•
The safety function remains effective in the case of a component failure.
•
The correct opening and closing of the safety function relays is tested automatically in
each on-off cycle.
•
Two emergency stop input circuits with cross-circuit detection.
•
Emergency stop function is triggered when either one of the two emergency stop
input circuits is interrupted or a cross-circuit between the circuits is detected.
The safety relay drives two power contactors responsible for switching the
outputs.
The power contractors are monitored by auxiliary contacts within a feedback
loop of the safety relay. In case of one power contactor failing by a stuck
contact the system can not be turned on again.
The red ERROR LED on front panel signals if one of the power contactors
got stuck
⚠ DANGER
Date: 2023/06/16 Page
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