Relay Connections - GE Bently Nevada 1900/27 Operation And Maintenance Manual

2.7 Relay Connections

Alert and Danger relays give two levels of alarm. Use the Alert relay to annunciate
high vibration that is nearing the Danger (shutdown) setpoint. Possible
annunciators include a buzzer, horn, light, or a signal sent to the plant computer.
The Danger relay is dedicated to the Danger setpoint and will go into its alarm
state when the vibration level exceeds the Danger setpoint.
A missed trip or false trip can occur if the Alert relay
is used to signal a shutdown.
Only the Danger relay, because it is dedicated to the
Danger setpoint, is intended for machinery protection
(shutdown) in the event of high vibration. The Alert
relay is intended for non-machinery protection
functions, such as annunciating a high vibration
condition or a system fault (NOT OK), or for starting a
spare machine in the event a primary machine is
shutdown by the Danger relay as a result of high
vibration in the primary machine.
WARNING
Section 2 - Installation
15