Esd Functions - Samson 3730-3 ESD Mounting And Operating Instructions

Description
Operation
The positioner can be operated on site using
the rotary pushbutton (see section 2.1.1
"On-site operation"). Alarms are indicated
on the LCD and issued over the fault alarm
output (condensed status).
The TROVIS-VIEW 3 software allows for
convenient operation when communicating
through the SAMSON SSP interface proto-
col. Thanks to DD and the FDT/DTM con-
cept, the ESD functions can easily be inte-
grated into the process control system or as-
set management system.
The instructions concerning operation in the
following sections refer to operation with
TROVIS-VIEW 3.
Note! All parameter settings entered in the
user interface need to be downloaded to the
positioner to become effective.
1.2

ESD functions

ESD mode
In ESD mode, the safety shut-off valve is
moved to a specific set point within its work-
ing range. The valve does not perform any
control tasks anymore. The valve is fully
closed in case of an emergency.
In its basic setting, the positioner behaves
similar to a solenoid valve, which keeps the
attached valve to a set position, e.g. open.
For test purposes, the partial stroke test can
either be started manually (ESD Man) or
triggered automatically according to sched-
ule (ESD Auto).
4
EB 8388-1 EN
Partial stroke test
The partial stroke test integrated into the
positioner can prevent a normally open
valve or a valve in its end position from
seizing up or getting jammed.
As the course of the partial stroke test is
plotted, the dynamic control response can
also be analyzed.
During the test, the valve is moved out of the
end position or from a start value either in
steps or in a ramp function until it reaches a
defined final value. Then, the valve is moved
back again to its initial position.
The partial stroke test is performed, for ex-
ample between 10 and 15 % of the rated
travel, starting from the end position while
the plant is running, yet without disrupting
plant operation. The start and stop values
for the partial stroke test can be configured
by the user.
The following test cancellation conditions
provide additional protection against the
valve slamming shut and moving past the fi-
nal value:
4
Valve position x
4
Drive signal y
4
Maximum test time is exceeded
4
Tolerance range exceeded
The course of the controlled variable x , ref-
erence variable w , setpoint deviation e , and
drive signal y parameters is saved in the
positioner, assigned to the operating hours
counter.
The dead time, T63 , T98 , overshooting , rise
time , and response time parameters of a
step response test are analyzed separately