Speed Governor for Steam Turbine

If you can access this site you could have Googled for yourself. Redundancy as in more than one speed sensor input or output or what? For total redundancy how about the following copied directly from Woodwards Site found at http://www.google.com/search?hl=en&q=woodward+governor&aq=f&oq=

Redundancy
Optionally, two 505 Enhanced controls can be applied in a
parallel configuration to operate in a redundant master/slave
manner. With this configuration, the master 505 controls all
aspects of the turbine, and the slave 505 tracks the master
unit's PID and control modes, allowing it to bumplessly take
control of the turbine in cases of control, transducer, actuator,
or other system failures. Optionally, users can force manual
transfers between units to verify operation, make on-line
changes, or replace system devices. The 505 is designed to
interface with Woodward's redundant CPC offerings.

Thanks for your information.

You are right.

I called Woodward local representative and He confirm what you have mentioned in your reply.

505/505E - In-built redundancy is not possible (System redundancy) so, they provide 2 nos. 505, both in operation and in case, one fail the other one will start to take control.

Recently (Last year) Woodward introduced new model called 505-R - That is with in-built redundancy.

Other proven model is 5009 WHERE IN BUILT-IN REDUNDANCY IS POSSIBLE.

In case, if some one has more detail avaliable can share.

with regards,