Special Motor's Data 1

[AKassem]

On a special EX canned pump Motor ,
I Found some data on the motor's name plate which is
not clear for me such as :

PN = 50 & tE = 12 s

Any body knows the meaning of these ratings ?
Thank you for you help ,

 

[Pumpsonly]

PN 50= rated for 50 Bar working pressure
tE= the max.allowable locked rotor time at rated voltage. Applied to Exe -increase safety motor construction.