Samson 3730-3 Operating Instructions Manual page 73

â
SAFE
PST not
possible
â
PST not
possible
â
Fail-safe action of actuator
(fail-safe position operating
mode)
EB 8389 EN
Start conditions PST with application type = 'Open/Close valve'
Operating mode
w < 'Limit
fail-safe
position'
â
PST
Man
x [%]
w [%]
50
25
∆ t > 6 s
â
â
1, 3, 4)
â â
Operating point/valve position according to set point
â
AUTO
25 % w > 'Limit
< w > fail-safe
50 % position'
PST mode
â â
PST PST
Auto Auto
t [s]
â â
PST possible
1, 2, 3, 4) 1, 2, 3)
â â
PST starts once
1)
PST starts once by setting 'Auto test time'
2)
PST starts over binary input
3)
PST starts once over set point w (see section 4.1)
4)
Tests – Partial stroke test (PST)
â
MAN
â
PST mode
â â
PST PST
Man Man
â
1, 3)
â
â
PST
Auto
â
PST not
possible
â
73