Honeywell FTA-T-14 General Purpose Relay FTA

Configured for discrete switching in industrial control platforms, the Honeywell FTA-T-14 (FTA-T-14 Field Termination Assembly) provides direct physical/electrical execution of 2-wire relay output logic across PLC-based automation systems.

Hardware Specifications

PLC Control and Network Characteristics

• 4-20 mA HART loop protocol: The FTA-T-14 acts as the termination point for field devices controlled by PLC discrete outputs. It maintains electrical path integrity, ensuring that downstream relay states are cleanly transitioned without inducing noise in adjacent analog loops.
• FOUNDATION Fieldbus / Profibus PA connectivity: Integration with the control network is facilitated through the PLC backplane interface. The assembly ensures deterministic switching performance, allowing the PLC to maintain tight control over field-side actuators and solenoid valves.
• Channel-to-channel isolation: The assembly utilizes mechanical relay isolation to separate field-side load circuits from the low-voltage control backplane. This isolation is necessary to prevent high-voltage transient coupling from reaching the PLC’s processing logic.
• Cold junction compensation (CJC): While the FTA-T-14 is dedicated to discrete switching, its robust terminal design ensures that thermal gradients are minimized, preventing localized heating from impacting neighboring high-precision signal cards in the rack.

Frequently Asked Questions

Q: Can the FTA-T-14 be used for high-frequency pulse width modulation (PWM)?

A: No. As a general-purpose relay module, the FTA-T-14 uses mechanical relay contacts that are subject to physical wear and have limited switching frequency. It is intended for steady-state or low-duty-cycle switching applications; PWM applications require solid-state output assemblies.

Q: Is the relay output polarity sensitive?

A: The 2-wire configuration is generally non-polarized for AC applications; however, when switching DC loads, ensure that the polarity aligns with the relay contact ratings and internal suppression diodes if required for load protection.

Field Installation Guidelines

• Mounting: Secure the FTA-T-14 assembly to the DIN rail or backplane within the control cabinet. Ensure the unit is mounted in a vertical orientation to facilitate natural convection cooling for the relay coil drive circuits.
• Grounding: Bond the module chassis to the main cabinet ground bus using a short, low-impedance copper strap. This is mandatory to maintain signal reference levels and to provide a path for discharge of EMI captured on field wiring.
• Wiring: Terminate field wiring using the 2-wire screw terminals. Maintain a separation of at least 150 mm between these output lines and sensitive analog instrument signals to prevent inductive noise injection during relay activation or de-energization.