Rockwell Automation T8442 Trusted TMR Speed Monitor - Manual

Trusted TM
PD-T8442
Issue 8 Apr 10 PD-T8442 1
Trusted
TM
TMR Speed Monitor
Introduction
The Trusted TM T8442 TMR Speed Monitor monitors the shaft speed and acceleration of rotating
machinery. It provides machine protection for over-speed and over-acceleration shutdown functions.
Typical machinery applications include steam and gas turbines driving pumps, compressors and
generators. A T8442 Speed Monitor Module within a Trusted
TM System provides the capability to
perform turbine speed control independent of the machinery protection functions.
System response times are often critical for these types of application. To minimise processing delays
the T8442 operates as a self contained fault tolerant control sub-system within the Trusted
TM system
environment.
Each T8442 has three monitoring and control groups. Each group provides the speed monitoring and
shutdown control facilities required for one rotating machine. Up to three turbine trains can be handled
by a single T8442. A single rotating machine group comprises of three separate Triple Modular
Redundant (TMR) speed input channels and two separate quad redundant, fault tolerant output drive
structures. Turbines having more than three speed pickups can be accommodated by combining
monitoring and control groups.
The speed input channels are designed to interface directly with a Trusted TM T8846 Speed Input Field
Termination Assembly (SIFTA). A single T8846 provides signal conditioning and field cable termination
facilities for the nine TMR speed input channels required for three rotating machine groups. Both
active and passive speed probes can be accommodated by the T8846. Active probes can be powered
from the field cable termination.
The shutdown control outputs are designed to interface directly with three Trusted TM T8891 Speed
Output Field Termination Assemblies (SOFTA). A single T8891 contains the two quad redundant, fault
tolerant, volt free contact structures required for a single rotating machine group.
The inter-connections between the module and the field termination assemblies are provided by a
Trusted
TM TC-801 cable assembly.
Features
• Three rotating machine groups.
• Three Triple Module Redundant (TMR) speed inputs per rotating machine group.
• Active or passive probe speed inputs
• Two quad redundant, fault tolerant, volt-free shutdown control output structures per rotating
machine group.
• Galvanic isolation between field Inputs/Outputs.
• On-board Sequence of Events (SOE) reporting with 1ms resolution.
• Hot standby module configurations using companion slot.
• Hardware Implemented Fault Tolerance (HIFT).
• Front panel status LEDs indicate module health, operating mode and rotating machine
group Input/Output status. Comprehensive automatic diagnostics and self-test.
• T 7 V Certified IEC61508 SIL 3