The Honeywell 51204166-125 is a digital output fault-safe (FTA) relay module designed for industrial control systems, particularly those based on Honeywell’s Universal Control Network (UCN) architecture, such as TDC 3000 and Experion PKS. It serves as a critical interface for converting digital control signals from the DCS controller into discrete outputs to drive field devices like solenoid valves, motor starters, or alarm indicators. The FTA (Fail-Typically-Active) design ensures that the relay defaults to a safe state (e.g., de-energized) in the event of a module failure, making it suitable for safety-critical applications in industries like oil & gas, chemical processing, and power generation.
Relay Performance:
- 16 Form C (SPDT) relay channels with independent control, supporting both dry and wet contact applications.
- High switching capacity: 10 A @ 24 VDC (contact rating) and 16 A relay rating, capable of handling high-power loads in industrial environments.
- Fast response time: Less than 10 ms release time for rapid actuation in time-sensitive control loops.
Safety & Reliability:
- Fault-safe design (FTA): Ensures outputs fail to a predefined safe state (e.g., open circuit) during module malfunctions, complying with IEC 61508 SIL 2 requirements
- IP65 environmental protection: Dust-tight and water-resistant housing for operation in harsh conditions (e.g., outdoor or dusty environments).
- 2.5 kV galvanic isolation: Protects against electrical noise and transient voltage spikes from high-voltage equipment.
Compatibility:
- UCN network integration: Communicates with Honeywell controllers (e.g., C200, C300) via UCN at 1 Mbps for seamless integration into existing DCS setups
- Legacy system support: Compatible with TDC 3000 and Experion PKS systems, with migration pathways available for phased upgrades to modern platforms like ABB 800xA
Configuration & Diagnostics:
- Configurable via Honeywell Engineering Workstation: Supports channel-level parameterization (e.g., voltage thresholds, fail-safe mode) and real-time status monitoring.
- LED indicators: Provide visual feedback for power, fault status, and channel activity.
| Parameter | Description |
|---|
| Relay Type | 16-channel Form C (SPDT) digital output relay |
| Input Signal | 24 VDC ±10% (coil voltage) |
| Output Rating | 10 A @ 24 VDC (contact); 16 A (relay) |
| Voltage Range | 0–125 VDC (output load) |
| Response Time | <10 ms (release time) |
| Temperature Range | -40°C to +85°C (operation); -40°C to +100°C (storage) |
| Communication | UCN (1 Mbps); RS-232 diagnostic port |
| Certifications | CE, UL, CSA, IEC 61508 SIL 2, ATEX (Ex II 2G Ex d IIC T6) |
| Physical Dimensions | 120 mm × 80 mm × 30 mm (rack-mounted) |
| Weight | 0.4 kg (0.88 lbs) |
Modular Architecture:
- Rack-mounted in Honeywell UCN I/O chassis, supporting up to 8 modules per rack for scalable I/O expansion.
- Hot-swappable: Allows module replacement without system shutdown, minimizing maintenance downtime.
Redundancy & Fault Tolerance:
- Optional dual power supplies for fail-safe operation in mission-critical applications.
- Built-in self-test (BIST) with diagnostic alerts for open circuits, short circuits, or relay wear.
Industrial Compliance:
- Designed for shock (50 G peak) and vibration (2.5 G RMS) resistance, compliant with IEC 60068-2 standards.
- Extended temperature range (-40°C to +85°C) for extreme industrial environments.
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