ABB Triguard SC300E Safety Manual

Also see for Triguard SC300E: User manual

Contents

ABB Triguard SC300E Safety Manual Manual pdf 13 page image

Issue 5 - September 2006 Page 13 of 65Note that during the change-over period the outputs of a HR partnership could be frozen for upto 2 seconds.The frequency of a main to standby, auto hot repair cycle for a HR partnership is calculated by:number of HR partners + 1 * swap time (hours)This period should not exceed the admissible repair times, see Appendix 2.If the process time constraint is less than 30 seconds, or only single sensors are provided forprocess measurement, then all input modules associated with safety loops must also beconfigured with adjacent hot repair partner slots.3.3.1 InputsSafety inputs to a Safety System will be either Normally Energised Digital Inputs (De-Energiseto Trip) or Analogue Inputs.3.3.1.1 Digital InputsDe-energise to trip inputs (usually termed fail-safe) will be used for all safety digital inputs. Thenumber of safety monitoring signals required for each safety parameter will depend primarily onthe safety integrity level (safety classification) required to be achieved, the 100% proof test cyclerequired and the level of diagnostics available from the field device.All safety digital inputs will be wired to a Digital Input Termination Card. Where the safetyintegrity level requires that more than one field sensor monitoring a safety parameter, each ofthese sensors should be, where practical, wired to separate Termination Cards. The Simplexpart of the termination card (eg fuses) must be considered for reliability analysis as part of thefield loop.The Termination Card will be connected to the Triguard SC300E Input Module via a standardsystem cable which connects to the socket on the appropriate Hot Repair Adapter Card (THR)or chassis slot.Through the hot repair adapter card, where required, and the chassis backplane connector theinput signal is connected to the configured digital input slot position where a Digital Input Modulewould be located.All the chassis slots and, where required, its hot repair partner slots configured for the DigitalInput Module must also have the coding blocks fitted and configured for this type of module asspecified in the Module and Chassis Users Manuals.Where the safety integrity level requires that separate sensors are used to monitor the samesafety parameters they should be configured to separate Digital Input Modules where practical.3.3.1.2 Analogue InputsAnalogue transmitters are used to monitor safety parameters and inherently provide anincreased level of diagnostics with respect to a simple fail-safe digital input. Analogue signalsalways provide values within a set operating range. For safety related transmitters this should be4-20mA or 1-5 volts allowing for fault indication below say 3mA (0.75V) and 20mA (5V). If over-range detection is required a 0-10V input module must be used. All monitored faults from theanalogue signals must be used by the application software to produce fail-safe results (eg failedtransmitter demands a shutdown).The number of analogue transmitters used to monitor a safety parameter will be dependent onthe system integrity level (safety classification) requirement of the loop, the 100% proof testcycle of the loop and the level of diagnostics available from the transmitter.