XNX-UTAV-RNCB1 Honeywell Universal Gas Transmitter MPD Catalytic Bead

Overview

The XNX-UTAV-RNCB1 Honeywell Universal Transmitter delivers continuous, high-precision monitoring for 0–100% LEL combustible hydrocarbon gases. Engineered with a lightweight, marine-grade painted LM25 aluminum enclosure, this unit comes pre-configured with an MPD catalytic bead sensor cartridge (CB1). It provides dual-output safety architecture combining standard 4-20mA signal transmission with integrated HART communication alongside three fully programmable SPCO output relays for direct local interlock control.

Configuration Architecture Breakdown

• Honeywell XNX Series Platform
  • Approval Rating [U]: UL / CSA Certified (Class I, Division 1, Groups B, C, D)
  • Thread Entry [T]: 4 x 3/4" NPT Conduit Entries
  • Housing Construction [A]: Painted LM25 Marine-Grade Aluminum (5 lbs / 2.3 kg)
  • Input Personality [V]: Millivolt (mV) Bridge Interface for MPD / 705 Sensors
  • Hardware Option [R]: 3 x Internal Relays Installed (2 Alarm, 1 Fault)
  • Local Interface [N]: No External Port Installed (Standard Enclosure)
  • Integrated Sensor [CB1]: MPD Catalytic Bead Cartridge (0–100% LEL Combustible)

Technical Specifications & Operational Limits

Compatible Hardware & Field Application Scenarios

• Compatible Sensor Assemblies:
  • MPD Series Cartridges (Catalytic Bead and Infrared options)
  • Model 705 & 705HT High-Temperature Catalytic Bead Sensors
  • Sensepoint & Sensepoint HT Heavy-Duty Field Transducers
• Target Industrial Deployments:
  • Class I, Division 1 hazardous areas requiring North American UL/CSA compliance standards.
  • Gas compressor stations, pipeline metering skids, and valve manifold rooms.
  • Industrial boiler rooms, thermal oxidizers, and fuel storage facilities.

Diagnostic & Self-Monitoring Capabilities

The XNX-UTAV-RNCB1 Honeywell transmitter incorporates continuous self-diagnostics that sample micro-controller execution, bridge baseline drift, supply voltage stability, and sensor element continuity. If a catalytic bead poison event or open-circuit failure occurs, the unit immediately drives the analog loop down to dedicated fault currents (≤2.0mA) and triggers the dedicated internal Fault Relay, enabling automated control room alerts before safety thresholds break down.

Model Selection Comparison & Engineering Recommendation

Selecting the correct communication architecture and regulatory approval profile ensures hassle-free field commissioning. Below is an engineering comparison between the XNX-UTAV-RNCB1 and the alternative XNX-AMSV-MNIF1 transmitter configuration:

Engineering Advice: Choose the XNX-UTAV-RNCB1 for installations in North American jurisdictions requiring UL/CSA listings, 3/4" NPT conduit runs, direct relay trips for local horns, and broad-spectrum catalytic bead detection. Conversely, select the XNX-AMSV-MNIF1 when deploying in ATEX/IECEx regions using metric M25 glands, multidrop Modbus RS-485 serial networks, or where long-term sensor immunity to catalytic poisons requires infrared optical sensing technology.

Global PLC Spare HUB's Insight

During a field retrofit at a North American natural gas compression plant, our engineers faced tight space constraints inside existing 3/4" NPT conduit channels. The compact 5 lb LM25 aluminum frame of the XNX-UTAV-RNCB1 Honeywell allowed easy single-technician mounting. By utilizing the internal relay option to switch local warning beacons directly on the skid, the team eliminated the need for extra junction boxes and interposing relays, reducing overall commissioning time by over 30% while retaining full 4-20mA HART reporting to the main SCADA system.

Warranty, Logistics & Ordering Terms

• Product Condition: 100% Brand New and Original Factory Supply
• Warranty Coverage: Standard 12-Month Quality Guarantee from dispatch date
• Order Processing Time: Fast dispatch within 24 to 48 hours post-payment verification
• Express Global Shipping: Courier shipping via trusted partners including FedEx, UPS, and DHL Express

Engineering Selection & Operational FAQ

What is the principal difference between 3/4" NPT entries and M25 entry configurations?

The 3/4" NPT threads on this model comply with North American rigid conduit standards, whereas M25 metric entries suit European cable gland practices. Always match entry threads to local electrical code specifications to maintain NEMA 4X integrity.

Can the CB1 catalytic bead sensor detect combustible gases other than methane?

Yes. The MPD catalytic bead element responds rapidly to a broad array of hydrocarbon gases and flammable vapors, including propane, butane, and hydrogen, calibrated to 0–100% LEL.

What happens if high exposure to silicones or sulfur occurs at the sensing site?

Silicones and heavy sulfides can poison catalytic bead elements over time, reducing sensitivity. In environments with known catalytic poisons, consider switching to an optical infrared sensor platform like the IF1 cartridge series.

How do technicians interact with the display in hazardous locations?

Field calibration and menu navigation are performed using a magnetic wand held against the glass window, allowing non-intrusive setup without opening the explosion-proof housing or issuing a hot-work permit.

Are the internal relay contacts rated for direct AC power switching?

Yes. The form "C" SPCO relay contacts carry ratings up to 250 VAC at 5A or 24 VDC at 5A under resistive loads, suitable for driving local strobes, horns, or small isolation solenoids.

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