<Appendix A. Safety Instrumented Systems Installation>
A-1
IM 01C50T01-02EN
Appendix A. Safety Instrumented Systems
Installation
WARNING
The contents of this appendix are cited from
exida. com safety manual on the YTA series
temperature transmitters specifically observed
for the safety transmitter purpose. When using
the YTA for Safety Instrumented Systems (SIS)
application, the instructions and procedures in
this section must be strictly followed in order to
preserve the transmitter for that safety level.
A.1 Scope and Purpose
This section provides an overview of the user
responsibilities for installation and operation of the
YTA in order to maintain the designed safety level
for Safety Instrumented Systems (SIS) applications.
Items that will be addressed are proof testing, repair
and replacement of the transmitter, reliability data,
lifetime, environmental and application limits, and
parameter settings.
A.1.1 Hardware and Software Revision
Hardware revision
Software revision
S1
R1.03.01
R1.04.01
A.2 Using the YTA for an SIS
Application
A.2.1 Safety Accuracy
The YTA has a specified safety accuracy of 10%.
This means that the internal component failures are
listed in the device failure rate if they will cause an
error of 10% or greater.
A.2.2 Diagnostic Response Time
The diagnostic test interval of YTA is less than 60
seconds and the diagnosis response time (time to
detect and notify an interval failures) is less than 2
seconds.
A.2.3 Setup
Set the ranges and units by the HART configuration
toll. After configuration, make sure that the ranges
and units are set correctly. The calibration of the
YTA must be performed after parameters are set.
A.2.4 Required Parameter Settings
The following parameters need to be set in order to
maintain the designed safety integrity. Table A.2.1
describes the setting of the hardware error burnout
and hardware write protect switch. Table A.2.2
describes the parameter setting by software.
Table A.2.1 Required setting of hardware error
burnout and hardware write protect
switch
Item
Description
Hardware error
burnout direction
switch
To specify if the output should go
to 21.6 mA or higher or 3.2 mA
or lower upon detection of an
internal failure.
Write protect switch The write function disabled.
Table A.2.2 Parameters to be set by software
Parameter
Description
PV is
Set it to sensor1 or sensor2.
The set sensor will be analog
output.
AO Sensor BO Dir
To specify if the output should
go to High (21.6 mA or higher)
or Low (3.6 mA or lower) upon
detection of an sensor failure.
Sns1(2) Damp
*1
Set to 0 seconds.
Only the Sensor Damp entered in
“PV is”.
AO Damping
*1
Set to 10 seconds.
AO Damp point
*1
Set the damping threshold to
100%.
Software write
protect
*1
Set a password with “New
password” and the writing
function disabled.
*1: There is no setting restriction in the software R1.03.01 or
earlier.
When AO is 10 seconds, the safety response time
within the safety accuracy is 25 seconds.
