05701-A-0325 | Honeywell | DC Input Card

Honeywell 05701-A-0325 DC Input Card

The Honeywell 05701‑A‑0325, also cataloged as the 05701‑A‑0325 DC Input Card, operates as the primary power‑entry module for routing 24 VDC supply and auxiliary backup inputs through the Engineering Card and sub‑rack backplane within Honeywell fixed‑gas control assemblies.

Hardware Specifications

Channel‑to‑Channel Isolation in Honeywell Power‑Distribution Cards

Within Honeywell process‑control racks, the DC Input Card maintains deterministic separation between PSU and AUX paths using diode isolation. This prevents back‑feeding between supplies and stabilizes 24 VDC distribution across the backplane. The isolation approach aligns with Honeywell’s broader process‑control design practices, including predictable boundaries used in 4‑20 mA HART loop protocol and Fieldbus/Profibus gateway modules.

Frequently Asked Questions

Q: Can the DC Input Card power all cards in the rack? A: Yes, but installations with more than eight 5704 Catalytic Cards should power Control Cards through their Quad Relay Interface Card to avoid excessive backplane current.

Q: Are PSU and AUX inputs electrically isolated? A: Yes. Diode isolation prevents cross‑flow between the primary and auxiliary supplies.

Q: Can the card be removed without disconnecting wiring? A: Yes. The two‑part TB1 terminal block allows card removal while retaining field wiring.

Field Installation Guidelines

• Route the 24 VDC supply through TB1 and verify correct polarity before energizing.
• Maintain separation between PSU and AUX wiring to preserve diode isolation behavior.
• Ensure the fuse rating matches system requirements before commissioning.
• Keep DC wiring segregated from high‑voltage conductors to reduce interference.
• Validate backplane voltage distribution after installation using system diagnostics.