Description

The Invensys Triconex 3805E is an enhanced analog output module designed for use within the Tricon Triple Modular Redundancy (TMR) safety system. This module provides 8 high-reliability output points with 12-bit resolution, specifically engineered to drive final control elements such as valves and actuators via a standard 4-20 mA current loop. Its TMR architecture ensures continuous process operation even in the event of a single component failure, making it a critical asset in safety-instrumented systems (SIS) within refineries, offshore oil platforms, and power generation facilities.

Features

• TMR Architecture: Utilizes triple modular redundancy with hardware voting to ensure high availability and fault tolerance.
• Rapid Switching: Executes a transition to functional legs in less than 10 ms upon detection of a leg failure.
• DC-Coupled Design: Eliminates the need for bulky output transformers while simplifying field wiring.
• Over-range Protection: Integrated protection rated at +42.5 VDC to mitigate damage from field-side voltage spikes.
• High Resolution: 12-bit output resolution for precise control of field devices.

Applications

The 3805E is intended for high-availability safety-critical environments, including:

• Emergency Shutdown Systems (ESD)
• Burner Management Systems (BMS)
• Critical Process Control loops in petrochemical and nuclear industries
• Turbine control and monitoring

Technical Specifications

Installation Guidelines

• ESD Precautions: Always use a grounded wrist strap when handling the module to prevent electrostatic discharge damage to internal components.
• Power Down: Ensure the Tricon chassis power is disconnected or the slot is powered down before inserting or removing the module.
• Seating: Ensure the module is fully seated and the locking levers are engaged to guarantee proper backplane connection.
• Wiring: Use shielded twisted-pair cabling for 4-20 mA loops to minimize EMI/RFI interference. Ensure proper grounding of cable shields at the field side or chassis ground as per site safety standards.
• Environment: Maintain adequate airflow within the cabinet to ensure the module operates within its specified temperature range (0 to 60 deg C).

FAQ

What is the primary function of the 3805E module?

The 3805E is an analog output module that provides 8 channels of 4-20 mA signals to drive field devices like actuators, specifically designed for the Triconex TMR safety system.

Does this module require external power?

The module is powered via the Tricon chassis backplane; however, the field loop power for the 4-20 mA outputs is typically provided by an external source connected through the field termination assembly.