Det-Tronics PIRECL Infrared Hydrocarbon Gas Detector PointWatch Eclipse SAFETY MANUAL - Manual (Page 2)

5.1 95-8630 2
DESiGN
The PIRECL is an infrared hydrocarbon gas detector
that is classified as Type B smart device according
to IEC61508. It provides an isolated 4-wire 4-20 mA
output that is proportional to hydrocarbon vapor
concentrations from 0-100% lower flammable limit
(LFL). The PIRECL contains extensive self-diagnostics
and is programmed to send the current output to a
specified failure state (3.6 mA or less) upon internal
detection of a failure. Optional Alarm and Fault relay
contact outputs are available in addition to the analog
signal output, and can be programmed in the field
by the user. The Safety Certification for the PIRECL
includes both the standard version with analog output
only and the version with analog output and optional
relay outputs.
Safety-Certification of the PIRECL includes:
• the High Alarm, Low Alarm, and Fault relay outputs
• the 4-20 mA output.
RS-485 Modbus signal output is not part of the SIL
certification.
Det-Tronics FlexVu ® UD20 Universal Display Unit has
been evaluated as a loop-powered device approved for
use in-line with a Safety-Certified PIRECL. Failure rates
for the PIRECL when connected to a UD20 are listed in
the Failure Rates table at the end of this manual.
Non-interfering interfaces
Safety-Certification of the PIRECL includes the following
non-interfering interfaces:
• LEDs
• Magnetic switches
• HART Communication
The HART communication protocol is non-interfering
and is to be used for diagnostics within the SIL 2
safety loop in the Safety operation mode. Diagnostics
are defined as read only information. Local HART
communication with the PIRECL via the onboard
intrinsically-safe communication port using a handheld
HART field communicator, or AMS program connected
to the 4-20 mA output, is acceptable. Proper
analog signal loop resistance must be installed as
documented in the instruction manual to enable local
HART communication. The end user must perform
calibration after any configuration changes.
VALiD iNPUT rANGE
PIRECL fault and alarm annunciation is provided on the
4-20 mA signal output loop by signaling to a specific
mA current output level. The user SIF must monitor
the 4-20 mA output for fault and alarm conditions
and take appropriate action according to the specific
requirements of the SIF. The receiving device must be
programmed to indicate a fault condition when current
levels reach under-current of 3.6 mA or less or over-
current of 21 mA or more.
NOTE
The PIRECL analog signal output is not safety-
rated during detector warm-up, configuration
mode, calibration mode, and during signal output
loop testing. Alternative means should be used
at the job site to ensure facility safety during
these activities.
DiAGNoSTiC rESPoNSE TiME
The PIRECL will perform all critical diagnostic functions
within one hour, worst case diagnostic detection time.
CErTiFiCATioN
The PIRECL Safety-Certified version is certified SIL 2
Capable by exida ® to IEC61508 for single input use in
low demand, SIL 2 Safety Instrumented Systems.
SAFETY-CErTiFiED ProDUCT iDENTiFiCATioN
Safety Certification of all PIRECL models meeting SIL
2 safety standards is clearly identified on the product
label.