Application Scenarios
In an offshore oil and gas platform, the fire and gas safety system must trigger audible alarms, close ventilation dampers, and release clean agent suppression upon detecting flame or combustible gas. The System 57 controller processes the detection logic, but the actual switching of high-current field devices requires dedicated relay outputs. When a Four Channel Control Card detects a fire condition, the connected 05704-A-0123 energizes its configurable relays—eight single-pole change-over and four single-pole single-throw—to simultaneously activate the alarm horn, signal the damper actuator, and notify the platform’s emergency shutdown system. Without this expansion card, the control card’s built-in relay capacity would be exhausted after wiring only a few critical outputs, forcing engineers to add external interposing relays that consume cabinet space and introduce additional failure points. The 05704-A-0123 solves this by providing a compact, rack-mounted expansion that keeps all safety switching within the certified System 57 enclosure.
Parameter
| Parameter | Value/Description |
|---|---|
| Product Model | 05704-A-0123 |
| Manufacturer | Honeywell |
| Product Category | Expansion Relay Card (Fire & Gas Safety System) |
| Compatible System | Honeywell System 57 (5704F Four Channel Control Card / Hex Relay Interface Card) |
| Relay Outputs | 12 additional relays (8 SPCO + 4 SPST) |
| Total System Capacity | Up to 16 relays when paired with host interface card |
| Relay Configuration | Configurable as fire, fault, or inhibit alarms; individual or master outputs |
| Operating Voltage | 18–32 VDC (via System 57 rack backplane) |
| Power Consumption | 1.7 W typical per interface assembly |
| Rack Space | Occupies two slots when connected to Hex Relay Interface Card |
| Field Terminals | Screw terminals, accepts up to 2.5 mm² (14 AWG) |
| Dimensions | 11.8 cm × 13.1 cm × 2.4 cm |
| Weight | 0.22 kg |
Technical Principles and Innovative Values
- Configurable Relay Assignment for Flexible Safety Logic: Unlike fixed-function relay cards, the 05704-A-0123 allows each of its 12 relays to be individually configured as a fire alarm, fault alarm, or inhibit output. This configurability means a single card type can serve multiple applications across a plant—one installation might use all 12 relays for fire zone annunciation, while another assigns half to fault signaling and half to suppression release. This reduces spare-parts inventory and simplifies engineering documentation.
- Seamless Rack Integration Without External Wiring Complexity: The card connects directly to the Hex Relay Interface Card via the System 57 backplane, drawing power and communicating through the rack’s internal bus. Field wiring lands only on the front-panel screw terminals, and the modular construction supports hot-swap replacement without disturbing adjacent channels’ field wiring. This design eliminates the need for a separate power supply, external communication cabling, or additional DIN-rail mounted relay banks.
- Certified Safety System Compatibility: As a component of the System 57 platform, the 05704-A-0123 inherits the certifications of the host system, including CE and EN54-2 compliance for fire detection and alarm systems. This means the expansion relays do not compromise the safety integrity of the overall fire and gas loop—a critical distinction from using general-purpose industrial relays in a safety-critical application.
