Page 455 - Offshore Electrical Engineering Manual

442 CHAPTER 2 Preparation and Use of Performance Standards

INSTALLATION: PERFORMANCE STANDARD: EMERGENCY SHUTDOWN SYSTEM (cont.)

Functions Element Assurance
Reliability & availability Reference
The ESD system is a Category 1 safety system which provides protection of personnel and the installation, as Installation Safety Case
defined in the maintenance management strategy. Test and maintenance procedures have been prioritised
accordingly to provide a high integrity ESD system and are contained within the maintenance management SIL Assessment Report
system. The nominal ESD system availability is 99.997%.
Contracts with Health Care providers specify reliability targets which are continuously under review.
Component Test & Frequency Assurance
Shutdown Field Devices 2/n voting is fed into the ESD system for initiation. The ESD system does Verified through inspection
not rely upon cascade effects to produce shutdowns of related process and testing.
systems. Reference ESD
Maintenance Routines
ESD The ESD system is fail safe and line monitored. The ESD system is Verified through inspection
designed to fail to safety on fault detection in any single channel section of and testing.
a shutdown path. Reference ESD
Maintenance Routines.
Level 3 - six monthly; Other levels - yearly
Cabling and Power A hardwired matrix displays the status of system inputs, outputs, override Verified through inspection
and reset status and the health of the system. and testing.
Reference ESD
The system monitors the status of power supplies and shutdown paths and Maintenance Routines
alarms all faults. A single channel fault in any section of the system
produces a fail-safe response.
FIGURE 9.2.1, cont’d