05701-A-0329 | Honeywell Triple DPCO (Double Pole Changeover) Relay Card

Product Overview

The Honeywell 05701-A-0329 is a Triple DPCO (Double Pole Changeover) Relay Card with integrated 4-20 mA analog output for the System 57 gas detection platform. It provides eight DPCO relays (two each for A1, A2, A3, plus Fault and Inhibit) and a proportional current loop output for external DCS/PLC integration.

Key Specifications

• Model Number: 05701-A-0329
• Series: Honeywell System 57
• Product Type: Triple DPCO Relay Card with 4-20mA Output
• Relay Configuration: 8 Total — 2× A1, 2× A2, 2× A3, 1× Fault, 1× Inhibit
• Relay Contact Type: Double Pole Change Over (DPCO)
• Analog Output: 4-20 mA Current Loop
• Output Accuracy: ±0.5% FS Typical
• Input Power: 24 VDC (via System 57 Backplane)
• Power Consumption: 1.6W
• Isolation: Galvanic isolation between channels and system logic
• Dimensions: 170 mm × 25 mm × 112 mm
• Weight: 245g (0.165 kg module; shipping weight 2.5 kg)
• Operating Temperature: -20°C to +50°C

Core Features

• Dual-functionality: relay outputs + 4-20 mA proportional signal retransmission
• Redundant DPCO switching logic with NO and NC contacts for fail-safe design
• Real-time concentration monitoring on SCADA via 4-20 mA output
• Galvanic isolation protects System 57 backplane from field-side noise
• Tiered alarm response: A1 (low-speed ventilation), A2 (high-speed exhaust), A3 (shutdown)

Applications

• Facility-wide gas safety and proportional process control
• SCADA/DCS integration for remote monitoring
• Emergency shutdown (ESD) systems
• Ventilation and damper control
• Fire and gas detection alarm management

FAQ

Q: How many relays does the 05701-A-0329 provide?
A: Eight relays total: two each for A1, A2, and A3 alarm levels, plus one Fault and one Inhibit relay.

Q: Is the 4-20 mA output compatible with third-party PLCs?
A: Yes, the standard 4-20 mA current loop ensures compatibility with Siemens, Rockwell, ABB, Yokogawa, and other industrial controllers.

Q: Does this card support hot-swapping?
A: No. Power down the System 57 rack before installation or removal to prevent backplane damage.

Installation Guide

1. Power down the System 57 rack completely.
2. Insert the relay card into the designated sub-rack slot.
3. Connect field relay wiring to the DPCO terminals.
4. Connect the 4-20 mA output to the external DCS/PLC input.
5. Configure alarm setpoints and relay operation via the engineering card.
6. Test all relay outputs and analog signal accuracy before commissioning.

Selection Tips

• Choose 05701-A-0329 when both relay outputs AND 4-20 mA retransmission are needed.
• For relay-only applications, consider 05701-A-0328 (Triple SPCO) or 05701-A-0327 (Double SPCO).
• For redundant relay outputs per alarm level, consider 05701-A-0330 (High Integrity).
• Verify load current requirements do not exceed 5A per relay contact.