Description
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | 05701-A-0329 |
| Manufacturer | Honeywell Analytics |
| System | System 57 / 5701 Control System |
| Product Type | Triple DPCO Relay Card |
| Relay Configuration | 2 × A1, 2 × A2, 2 × A3, plus Fault and Inhibit relay functions |
| Contact Type | Voltage-free changeover contacts |
| Relay Rating | 5 A @ 250 VAC / 32 VDC, non-inductive |
| Relay Operation | Selectable latching/non-latching and normally energized/de-energized |
| Card Power Consumption | Approx. 1.6 W for Triple DPCO configuration |
| Terminal Capacity | Up to 2.5 mm² / 14 AWG |
| Operating Temperature | -5 to +55°C |
| Storage Temperature | -25 to +55°C |
| Humidity | 20–99% RH, non-condensing |
| Approval | EN50270 |
| Status | Discontinued / legacy |
The Honeywell System 57 manual specifically identifies 05701-A-0329 as the Triple DPCO Relay Card. It provides connections between the sensor and control card and supplies voltage-free contact outputs for two A1, two A2, two A3 alarm levels, fault, and inhibit conditions.
Product Introduction
The Honeywell 05701-A-0329 is a Triple DPCO Relay Card used in the System 57 / 5701 gas detection control system. Its job is to take alarm, fault, and inhibit conditions from the associated control circuitry and make them available as voltage-free relay contacts for external annunciation, shutdown logic, interlocks, or plant alarm circuits. The System 57 documentation places this card in the relay/interface section of the 5701 architecture.
For maintenance work, this is a relay interface card rather than a general-purpose PLC I/O module. The distinction matters because the card’s terminal assignments and relay logic are tied to the System 57 architecture. The documented relay configuration includes A1, A2, A3, fault, and inhibit functions, while relay operation can be configured for latching/non-latching and normally energized/de-energized behavior.
05701-A-0329
Application Scenarios & Field Pitfalls
Engineering Pain Point
A common replacement mistake is treating 05701-A-0329 as a generic digital-output or relay module. It is specifically designed around the 5701 System 57 gas detection architecture. Using a card with a superficially similar relay count can result in incorrect alarm mapping or unexpected fail-state behavior.
Typical Applications
- Fixed gas detection systems using Honeywell System 57 controllers.
- Industrial process safety monitoring where A1/A2/A3 alarm levels require hardwired relay contacts.
- Plant alarm and shutdown circuits requiring isolated, voltage-free contact outputs.
- Gas monitoring installations where fault and inhibit conditions must be passed to external control or annunciation equipment.
Technical Pitfalls to Avoid
- Do not substitute it with a generic relay output card. The terminal arrangement is application-specific.
- Check relay energization philosophy. The documented card supports normally energized/de-energized and latching/non-latching configurations, so the installed system’s fail-state logic should be confirmed before replacement.
- Verify the complete part number. System 57 also uses closely related cards such as 05701-A-0327 and 05701-A-0328. The latter are different relay configurations and are not interchangeable simply because they occupy the same general card family.
Related Products
- 05701-A-0326 — System 57 Field Interface Double SPCO Relay Card; provides the field-interface version of the relay function.
- 05701-A-0327 — Double SPCO Relay Card; different relay arrangement from the Triple DPCO 05701-A-0329.
- 05701-A-0328 — Triple SPCO Relay Card; provides A1/A2/A3, fault, and inhibit functions with a different contact arrangement.
- 05701-A-0303 — High Integrity Relay Card; intended for higher-integrity relay applications with configurable relay outputs.
- 05701-A-0351 — System 57 Control Card; performs control functions rather than serving as the external relay interface.
- 05701-A-0301 — 4–20 mA Single Channel Control Card; associated with single-channel gas detection control.
- 05701-A-0302 — Catalytic Single Channel Control Card; used for catalytic sensor applications.
- 05701-A-0285 — System 57 Analog Output Module; provides analog output functionality rather than relay contacts.
- 05701-A-0361 — Engineering Card; used for System 57 engineering/configuration functions.
- 05701-A-0312 / 05701-A-0313 — System 57 Modbus interface options for RS-422/485 and RS-232 respectively.
Procurement Check
For 05701-A-0329, verify the installed System 57/5701 controller, relay configuration, terminal wiring, and energized/de-energized philosophy before installation. The documented rear-access connections identify individual A1, A2, A3, fault, and inhibit contacts, so a terminal-for-terminal comparison against the removed card is worthwhile before energizing the replacement.
