Rockwell Automation 8000 Series TMR System - Manual (Page 18)

OPERATOR AND MAINTENANCE MANUAL
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3. MAINTENANCE
The operator maintenance schedule for testing the SIS, sensors and actuators
should reflect the test interval used in the reliability/availability calculations.
The system should be configured to allow testing from the I/O module to the field
device.
Inputs
The purpose of the override is to allow testing of the sensor without executing a trip.
Inputs may be configured to have an override in the application logic which should
prevent the executive action but annunciate the alarm to the operator interface.
Analogue inputs should be tested over their full range.
Outputs
Output modules perform diagnostic tests as detailed in the Product descriptions.
Final element testing is usually performed by operators during scheduled plant
shutdowns.
Some systems use the 8000 Series Valve monitor module to perform frequent
partial valve tests while the plant is live. The cumulative data is analysed and
provides details of covert failures and wear, allowing planned maintenance before a
failure occurs.
Plant Maintenance
Maintenance to SIS sensors and final elements, e.g. calibration or
repair/replacement while the plant is live, will require a maintenance override
facility. Refer to paragraph 1.10.
SIS Housekeeping
The system should be kept clean at all times. Recommended 3 monthly
maintenance should include
(1) Visually inspect the following:
1) All fuses to ensure that they are intact.
2) All 8000 Series Cabinets rack and roof fan units are working satisfactorily.
3) All terminals for tightness.
4) All modules, relays and other equipment for correct and secure location in their
sockets.
5) For signs of contamination and corrosion, paying particular attention to cable
joints, cable terminations, MCBs, trunking etc.
(2) Lubricate all hinges and locks.
(3) Check that the 8000 Series Cabinets are correctly ventilated and grilles are free
from dust. In dusty environments, this check may be necessary more
frequently.