Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 05701-A-0302 |
| Manufacturer | Honeywell |
| Product Type | Single Channel Control Card |
| Host System | Honeywell System 57 |
| Compatible Models | 5701, 5704, 5704F |
| Input Voltage | 9–32 VDC |
| Input Current | 50 mA |
| Output Voltage | 0–5 VDC |
| Output Current | 25 mA |
| Alarm Levels | A1, A2, A3 + fault detection |
| Connection | System 57 rack backplane |
| Installation Environment | Indoor, non-hazardous area |
| Dimensions | 6.3 × 4.3 × 1.7 inches |
| Signal Isolation | Input / output / power isolated |
Product Introduction
The Honeywell 05701-A-0302 is a single-channel control card designed for the Honeywell System 57 gas and fire detection platform. It provides complete control for one detection channel — handling sensor excitation, signal conditioning, alarm threshold evaluation, and fault monitoring — all within a single card-slot footprint in the System 57 rack.This card matters in facilities where individual detector channels must operate independently with dedicated alarm logic. The A1/A2/A3 multi-level alarm structure lets operators set graduated warning and action thresholds per channel, while the built-in fault detection flags sensor open-circuit or short-circuit conditions before they become safety gaps. Field teams typically encounter this card in legacy gas detection panels at chemical plants, refineries, and utility facilities where System 57 was the standard architecture. (The 50 mA input draw keeps thermal load low even in densely populated racks — a detail that matters when you’re running 20+ cards in a single chassis.)
Installation & Configuration Guide
Phase 1: Preparation (10 min)
- De-energize the System 57 rack and apply lockout/tagout
- Identify the target slot position from the system channel map
- Photograph the existing card’s orientation and any jumper settings before removal
- Confirm replacement part number matches 05701-A-0302 exactly (check silkscreen label)
- Prepare ESD wrist strap — card electronics are sensitive to static discharge
Phase 2: Removal (5–10 min)
- Release the retaining mechanism on the faulty card (screw or lever, depending on rack version)
- Pull the card straight out from the backplane — do not angle or force it
- Inspect the backplane connector for bent pins, corrosion, or debris
- Place removed card in anti-static bag if retaining as spare
Phase 3: Installation (10 min)
- Align the 05701-A-0302 card with the designated slot guides
- Seat the card firmly into the backplane connector — verify full engagement with no visible gap
- Secure the retaining mechanism
- Reconnect field wiring to the detector input terminals per the channel assignment diagram
- Verify jumper/DIP settings match the original card configuration
Phase 4: Power-On & Test (10 min)
- Restore rack power
- Observe the card status LED — steady indication confirms normal operation
- Run the System 57 built-in diagnostic to verify channel communication
- Apply a known test gas concentration (or simulate with a calibrated source) to confirm alarm trip at A1/A2/A3 thresholds
- Verify fault detection responds to simulated sensor open/short conditions
Troubleshooting Quick Reference
| Symptom | Probable Cause | First Check |
|---|---|---|
| Card does not power on | Backplane contact failure or supply out of range | Measure 9–32 VDC at backplane slot; reseat card |
| No alarm response to gas | Sensor wiring fault or wrong channel assignment | Check field wiring continuity; verify channel map |
| Intermittent fault alarms | Loose backplane connection or EMI | Reseat card; check for nearby noise sources |
| LCD shows incorrect reading | Calibration drift or sensor mismatch | Recalibrate per System 57 procedure; verify detector type |
| Card recognized but outputs zero | Jumper misconfiguration | Compare jumper positions to original card photo |
| Communication error on rack bus | Backplane pin damage | Inspect connector pins under magnification |
Dimensions, Mounting & Wiring Notes
- Dimensions: 6.3 × 4.3 × 1.7 inches (H × W × D)
- Mounting: Card-edge insertion into System 57 rack backplane; retained by slot-level fastener
- Terminal Notes: Field detector wiring connects to card-edge terminals — input and output circuits are electrically isolated from each other and from the power rail
- Wiring Caution: Do not exceed 32 VDC on the input supply. Verify detector loop wiring matches the card’s expected signal type (catalytic bead, electrochemical, or infrared — depending on detector model paired with this card)
- Environment: Rated for indoor, non-hazardous area installation only. Do not install in classified hazardous zones without appropriate system-level certification
FAQ
Is the 05701-A-0302 a direct drop-in replacement for older System 57 cards?
It is, provided the host rack is a System 57 platform (5701, 5704, or 5704F) and the slot position matches the channel assignment. Check the revision suffix on your existing card — if it differs, confirm compatibility before ordering.I have a 5704F rack. Will this card work?
Yes. The 05701-A-0302 is listed as compatible with 5701, 5704, and 5704F platforms. The backplane connector and signaling are consistent across those models.What gas detector types does this card support?
It supports detectors configured for catalytic bead input as standard. Compatibility with electrochemical or infrared detectors depends on the detector model and its signal output characteristics — verify against the detector’s datasheet and the System 57 configuration manual.Can I use this card in a hazardous area?
No. The card itself is rated for indoor, non-hazardous area installation. The detector探头 (probe) may be rated for hazardous zones, but the card must remain inside the safe-area control panel.How do I recalibrate after installing a new card?
Use the System 57 configuration software or the card’s local interface to set alarm thresholds (A1, A2, A3) and perform a span calibration with a certified test gas concentration. The exact procedure depends on your System 57 software version — refer to the system commissioning manual.What’s the typical failure mode for this card?
Backplane connector corrosion from humidity exposure is the most common field failure. The second most frequent issue is power supply degradation causing intermittent resets. Both are preventable with proper panel sealing and regulated supply voltage.Is this part still manufactured by Honeywell?
No. The 05701-A-0302 is discontinued. Available units come from surplus inventory or refurbished stock. Confirm condition and test documentation with your supplier before purchasing.
