05701-A-0302 | Honeywell | Single Channel Control Card Catalytic

Description

The Honeywell 05701-A-0302 is a microprocessor-based gas monitoring interface card engineered specifically to control and process signals from catalytic bridge sensors within the System 57 framework. This single-channel control card interfaces directly with field-mounted combustible gas sensors, providing the essential excitation voltage and bridge conditioning circuitry needed to evaluate hazardous gas concentrations. Operable as an autonomous safety element inside industrial racks, the device continuously performs comprehensive self-testing loops to monitor internal operation, configuration integrity, and active sensor loop continuity.

The module incorporates a specialized four-part liquid crystal display on its front face to provide a local indication of flammable gas levels via an analogue bar segment representation alongside explicit numeric and diagnostic text strings. The processed sensor signals are evaluated against adjustable threshold points to trigger alarm states across the common sub-rack backplane, interfacing seamlessly with centralized alarm loops, industrial automation systems, and discrete safety shutdown mechanisms.

Features

• Features an integrated four-part liquid crystal display comprising a 25-segment analogue bar indicator, a 4-character digital concentration window, a 4-character message block, and operational status icons.
• Equipped with dedicated front-panel indicators including LEDs for A1, A2, A3 gas alarms, alongside system Fault and channel Inhibit indicators.
• Provides a front-facing Alarm Reset/Card Select push-button allowing operations personnel to reset latched alarm flags or toggle local programming configurations.
• Supports high-precision safety threshold engineering with Alarm Setting Point Resolution fully adjustable in discrete 1% fsd steps.
• Features low-drift signal conversion circuitry providing an Electronic Drift stability threshold restricted to less than plus or minus 2% over a 6-month continuous runtime.

Applications

• Fixed combustible gas monitoring networks in onshore petrochemical refineries and offshore production platforms.
• Specialized gas detection panels in heavy machinery spaces, marine engine rooms, and industrial boiler utilities.
• Marshaling cabinets requiring individual loop separation for catalytic bead sensors protecting critical manufacturing plant perimeters.

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Sub-Rack Installation: Slide the module into its designated slot inside the System 57 19-inch sub-rack frame, verifying that both the upper and lower mechanical guide rails are fully engaged before pressing the card home.
• Shielding and Interface Paths: Route all field sensor connections through the matching interface block or relay termination card using multi-conductor shielded cables up to 2.5mm2 cross-sectional area.
• Grounding for Catalytic Bridges: Terminate the external cable shielding sheath directly to the system earth grounding stud on the termination block assembly to isolate precision bridge signals from localized EMI/RFI noise.
• Single-Point Earth Termination: If the field-mounted sensor enclosure is connected to structural metalwork, ensure the shielding path is tied only at the controller rack frame to avoid creating hazardous ground loop pathways.
• Thermal Management: Maintain an unobstructed airflow path across the top and bottom ventilation openings of the sub-rack housing to preserve structural component life under full catalytic drive loads.

FAQ

• What is the difference between the 05701-A-0301 and this 05701-A-0302 model?

  The 05701-A-0302 comes factory-configured with an internal sensor drive module optimized to run and excite passive 3-wire catalytic bead sensors directly, whereas the 05701-A-0301 is tailored for active 4-20mA current loop transmitters.

• How are the local alarm thresholds calibrated or altered on this device?

  The trip values and full-scale calibration parameters are managed through an onboard microprocessor and written into an internal non-volatile memory block, which requires an external Engineering Card or compatible diagnostic software configuration kit to adjust.

• Is it necessary to power down the entire control rack to replace a single card?

  No, individual channels function as completely isolated control loops, permitting maintenance personnel to insert or remove a single module while neighboring slots remain fully operational.

• How should unused channels inside a multi-slot rack assembly be configured?

  Unused slots do not require empty cards; however, if a card is installed but not tied to a live sensor loop, the specific channel must be set to the permanently inhibited state via software or hardware bridges to avoid generating constant field fault states.