Fergusan Palin Protection Relay

[Cudas]

Has anyone come across a Fergusan Palin protection relay, model designation PBO? I am conducting a fault level study for a client and have come across this relay and require information on curve types (eg Extremely Inverse) or curve equations. Any help much appreciated.

 

[ozzyspark]

We are still using PBO type relays in our distribution network. However I believe that these were manufactured by Metropolitan Vickers?? If it is the same PBO relay it has a Standard Inverse timed curve and may also have a seperate instantaneous element. The current pickup level of the relay is adjustable via a plug setting, and the time multiplier setting via a "wheel". I do have the original publications for these relays from 1958 which are fairly comprehensive if you need any specific information let me know.