Samson 373 Series Operating Instructions

EB 8389 EN 27
Statistical information
4.1 Open/close (on/off) valve
3730-2 3730-3 3731-3 3730-4 3730-5 3731-5
• • • • •
The travel range of open/close (on/off) is
dened by the fail-safe position and the op-
erating point. As a result, the following pa-
rameters to determine the working range
and set point range are not analyzed and
cannot be changed.
− Travel/angle range start/end (Code
8/9)
− Travel/angle range lower/upper limit
(Code 10/11)
− Reference variable range start/end
(Code 12/13)
The discrete analysis of the set point is per-
formed in automatic mode.
Operating point
Limit operating point
Limit fail-safe positio
n
Fail-safe position
t [s]
25
50
∆t > 6 s
x [%]
w [%]
If the set point ( ) is below 'Limit operating
point' when the automatic mode starts, the
valve (
) moves to the fail-safe position. If
the set point increases and exceeds 'Limit op-
erating point', the valve moves to the 'Oper-
ating point'. The valve moves back to the
fail-safe position (0% in the example) if the
set point then falls below 'Limit fail-safe posi-
tion'.
Operating point
Limit operating point
Limit fail-safe positio
n
Fail-safe position
t <6s
t [s]
25
50
x [%]
w [%]
If the set point ( ) is above 'Limit operating
point' when the automatic mode starts, the
valve (
) moves to the operating point. The
valve moves back to the fail-safe position
(0% in the example) if the set point then falls
below 'Limit fail-safe position'.
Starting the partial stroke test (PST)
Operating point = Star
t (PST)
Limit operating point
Limit fail-safe position
Fail-safe position
End (PST)
Stop PSTStart PST
>
6
s
t [s]
x [%]
w [%]
t
25
50
A partial stroke test is started when the set
point (
) moves starting from the operating
point into the range between 25 and 50%

Samson 373 Series Specifications

General

Brand	Samson
Model	373 Series
Category	Valve Positioners
Language	English