PCB Piezotronics IMI SENSORS 686 Series Installation And Operating Manual page 16

Indicating High Levels of Vibration Simultaneously in Series (Such as Fan & Motor)
Figures 10 and 11 – Indicating High Levels of Vibration Simultaneously in Series (Such as Fan & Motor)
The Smart Switches are hooked up in series and installed on the two most loaded bearings across the coupling in
the horizontal direction. Pushing the Start pushbutton closes the M contacts and starts the motor and fan. If the
start-up delay option for the switches is enabled, the Smart Switches will not trip during the specified startup delay
time, regardless of the vibration level. After this delay, the switch relays will be activated if the vibration level on
both machines exceeds the alarm threshold for a period greater than the specified operation delay time. This
action will close the contact to the pilot lamp.
Since the NL (non-latching) option is specified, the pilot lamp will illuminate only while set threshold on both
machines is exceeded. Should the vibration level for one or both of the machines drop below the threshold value
(based also on the specified hysteresis), the pilot lamp will turn off.
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