Honeywell FS-TSAI-1620M Safe Analog Input Field Termination Assembly

The Honeywell FS-TSAI-1620M is a 16-channel safe analog input Field Termination Assembly (FTA) for the Honeywell FSC (Fail Safe Controller) system. It interfaces field-mounted transmitters with the SAI-1620m Safe High-Density Analog Input Module, accepting 0-20 mA and 4-20 mA current-loop signals and conditioning them for analog input processing. The assembly supports safety-related and non-safety-related signal applications.

Functional Description

The FS-TSAI-1620M provides the field wiring and signal-conditioning interface between analog transmitters and the controller's analog input hardware. Its input circuitry converts field current signals into proportional voltage signals for processing by the SAI-1620m.

The assembly provides 16 analog input channels, arranged in two groups of eight with a common 0 V reference within each group. This arrangement should be considered when checking field wiring, transmitter power distribution and grounding requirements.

Signal Interface and Configuration

• Accepts 0-20 mA and 4-20 mA analog current signals.
• Provides 16 field input channels.
• Interfaces with the Honeywell SAI-1620m safe analog input module.
• Supports external power monitoring.
• Provides field connections for analog signals, power and cable shields.
• Supports field circuits from Class I, Division 2 hazardous locations, subject to the applicable installation limits.

Signal Conversion and Transmitter Supply

The FTA converts the incoming current signal into a 0-4 V DC output for the SAI-1620m module, with a specified conversion accuracy of 0.10%. This allows the field termination assembly to handle current-loop interfacing while the associated input module performs the safety input processing.

For passive transmitters, the FTA provides an external supply path with a 270 ohm output resistance (±5%). The external supply requirement is 30 V DC, with a nominal FTA current requirement of 3 mA excluding input loop loads.

Protection and Field Wiring

Each channel has dedicated screw-terminal connections and a grounding terminal for analog cable shielding. The assembly uses 315 mA slow-acting fuses to protect the field circuits. Its terminal arrangement supports wiring up to 2.5 mm2 (AWG 14), with a specified 7 mm stripping length and 0.5 Nm tightening torque.

The FS construction is non-conformal-coated. It should not be confused with the FC construction, which uses conformal coating. This distinction is relevant when identifying replacement hardware for an existing cabinet.

Technical Specifications

Field Installation Guidelines

• Mount the assembly on a compatible TS32 or TS35 x 7.5 DIN EN rail.
• Connect the external 30 V DC supply and 0 V reference according to the designated terminal connections.
• Check the two groups of eight channels when allocating field signals and common references.
• Use the specified wire diameter, stripping length and terminal tightening torque.
• Verify fuse ratings and field-circuit electrical limits before connecting transmitters.
• Confirm the system interconnection cable and SAI-1620m interface before commissioning.

Frequently Asked Questions

Q: Which input module is compatible with the FS-TSAI-1620M?

A: The designated input module is the Honeywell SAI-1620m Safe High-Density Analog Input Module. The FTA converts field current signals into 0-4 V DC signals for this module.

Q: Can the FS-TSAI-1620M accept both 0-20 mA and 4-20 mA signals?

A: Yes. It supports both current-loop ranges, with a specified input current range of 0-25 mA. The field signal configuration must match the transmitter and Safety Manager application settings.

Q: Is FS-TSAI-1620M interchangeable with FC-TSAI-1620M?

A: Both belong to the TSAI-1620m FTA family and share the documented basic electrical specifications. However, FS-type modules are non-conformal-coated, whereas FC-type modules are conformal-coated. Confirm the required construction and installed hardware revision before replacement.