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SENSO
RS AN
D INS
TRUME
N
TATIO
N F
OR MAC
HINE
CON
DITION M
ONIT
ORIN
G
Automatic Machinery Shutdown Based on Normally Open Solid-State Relay
Figure 23
–
Automatic Machinery Shutdown Based on Normally Open Solid-State Relay
The Smart Switch is hooked up to provide automatic motor shutdown when the alarm threshold level is exceeded.
Pushing the Start pushbutton closes the M contact, and since the switch is Normally Closed, the solid state relay
will be energized and the RL contacts will be closed. This will start the motor. If the start-up delay option is
enabled, the switch will not trip regardless of the vibration level during the specified delay time.
After this delay, if
the vibration level exceeds the alarm threshold, it will be activated, thereby opening its contacts and de-energizing
the solid state relay input. This will open the RL contacts and shut down the motor.
Since the LA (latching) option
is specified, the solid state relay input will be constantly de-energized after this event even if the vibration level
drops below the alarm threshold value after shutdown. The Reset pushbutton should be pushed to reset the
switch and close the RL contacts before restarting the motor.
