Vibration detection equipment should always be in service on a turbine-generator system.
It is not adequate, for example, to manually add the vibration detection recorder after having
detected a field ground. The reason is that the second field ground may occur quite soon after
the first one and before any manual action is possible. The vibration detector should at least
provide an alarm, but preferably should issue a time-delayed trip of the generator and field
breakers. As noted previously, it is preferable that the vibration detector not trip the turbine,
but only the generator and field breakers.