Over-speed protection for turbines and pumps

The DSP can be software loaded with the specific measurement algorithm, which not only controls the sensor selection, but also the protection relay status and analogue output levels. This provides complete hardware autonomy from sensor through to the protection relay, combined with a high channel density (24 channels in a 3U format). 

It is typical for overspeed protection to utilise a two out of three voted channel arrangement to meet with stringent spurious trip requirements. This is implemented in G3 by utilising three modules, each with a single DSP channel to maintain channel hardware segregation, and configured with the overspeed algorithm.

G3 offers the advantage that the remaining module channels can be utilised for other machine measurements such as bearing vibration, shaft position or temperature.

The rack based system operates on a dual +24V power supply backplane, either connected externally, or derived from the optional G3 dual redundant rack based power supplies.

When high integrity protection is required, the IEC61508 international standard for functional safety can be applied to ensure that sufficient integrity is designed into the electrical/electronic systems employed for the safety function.  The Sentry G3 OSP achieves a SIL 3 rating in this respect.