Operation And Maintenance - Emerson Rosemount 644 Reference Manual

Reference Manual
00809-0200-4728
Custom alarm level
(1) Transmitter Failure, hardware or software alarm in LO position.
(2) Transmitter Failure, hardware or software alarm in HI position.
(3) Low alarm must be at least 0.1 mA lower than the low saturation value.
7.5

Operation and maintenance

7.5.1 Proof test
The following proof tests are recommended. In the event that an error is found in the
safety functionality, proof test results and corrective actions taken must be documented
at Emerson.com/Rosemount/Safety.
All proof test procedures must be carried out by qualified personnel.
7.5.2 Partial proof test 1
The partial proof test 1 consists of a power cycle plus reasonability checks of the
transmitter output. Reference the FMEDA Report for percent of possible DU failures in the
device.
FMEDA report can be found at Rosemount 644 Temperature Transmitter
Required tools: Field Communicator, mA meter
Procedure
1. Bypass the safety PLC or take other appropriate action to avoid a false trip.
2. Send a HART command to the transmitter to go to high alarm current output and
3. Send a HART command to the transmitter to go to the low alarm current output
4. Use the HART communicator to view detailed device status to ensure no alarms or
5. Perform reasonability check on the sensor value(s) versus an independent estimate
6. Restore the loop to full operation.
7. Remove the bypass from the safety PLC or otherwise restore to normal operation.
Emerson.com/Rosemount
(3)
verify that the analog current reaches that value. This tests for compliance voltage
problems such as low loop power supply voltage or increased wiring resistance. This
also tests for other possible failures.
and verify that the analog current reaches that value. This tests for possible
quiescent current related failures.
warnings are present in the transmitter.
(i.e. from direct monitoring of BPCS value) to show current reading is good.
Safety Instrumented Systems (SIS) Certification
March 2021
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