Product Overview
The Yokogawa SAI143-H53 is a 16-channel current-input module used in Yokogawa ProSafe-RS safety instrumented systems.
It receives standard 4–20 mA signals from field transmitters and transfers the measured process values to the safety-control station. The module is commonly used for safety-critical pressure, level, flow, temperature and gas-detection measurements.
Manufacturer and Model Information
| Item | Details |
|---|---|
| Manufacturer | Yokogawa Electric Corporation |
| Product family | ProSafe-RS |
| Complete model | SAI143-H53 |
| Product type | Current/analogue input module |
| Number of channels | 16 |
| Input signal | 4–20 mA DC |
| Installation | ProSafe-RS safety-control station |
| Redundancy | Supports dual-redundant installation |
| Country of manufacture | Japan |
| Application | Safety instrumented and emergency-shutdown systems |
Technical Specifications
| Specification | Details |
|---|---|
| Input channels | 16 channels |
| Rated input range | 4–20 mA DC |
| Permissible input range | Approximately 0–25 mA |
| Input impedance when powered | Approximately 250 Ω plus internal protection-circuit voltage drop |
| Input impedance when unpowered | 500 kΩ minimum |
| Data-update period | Approximately 40 ms |
| Channel arrangement | Module-isolated input channels |
| Redundant operation | Two modules can be configured for redundancy |
| Field power | Separate field power supply required |
| Module status | Front-panel system, field and power indications |
| Mounting | Compatible ProSafe-RS node and base unit |
| Field connection | Dedicated Yokogawa terminal board or interface cable |
The SAI143-H53 suffix and system-style code must be checked against the installed ProSafe-RS node, terminal arrangement and project documentation. Official Yokogawa SAI143 specifications
Main Features
- Sixteen 4–20 mA current-input channels
- Designed for safety-critical analogue measurements
- Supports redundant module configurations
- Fast input-data updating
- Continuous module and field-signal diagnostics
- Open-circuit and abnormal-signal monitoring
- High measurement stability
- Compatible with two-wire and four-wire transmitters
- Suitable for ProSafe-RS safety applications
- Front-panel module-status indication
- Removable module construction
- Designed for continuous industrial operation
- Supports online maintenance according to approved system procedures
- Integration with Yokogawa CENTUM control systems
Typical Field Instruments
The module can receive signals from compatible:
- Pressure transmitters
- Differential-pressure transmitters
- Level transmitters
- Flow transmitters
- Temperature transmitters
- Gas-detection transmitters
- Flame-detector interfaces
- Vibration transmitters
- Density and concentration transmitters
- Valve-position transmitters
- Current-output analysers
- Other safety-related 4–20 mA instruments
Safety Functions
The SAI143-H53 can form part of safety loops including:
- High-pressure shutdown
- Low-pressure shutdown
- Tank overfill protection
- Low-level pump protection
- High-temperature shutdown
- Low-flow shutdown
- Gas-concentration trip
- Compressor protection
- Burner and boiler shutdown
- Emergency process isolation
- Fire-and-gas system interfaces
- High-integrity pressure protection
The complete safety integrity level depends on the total safety loop, including sensors, controller configuration, final elements and proof-testing procedures.
Marine and Offshore Applications
- FPSO emergency-shutdown systems
- Offshore platform safety systems
- LNG and LPG processing vessels
- Marine fire-and-gas systems
- Cargo-handling safety controls
- Fuel-gas supply systems
- Compressor and pump protection
- Boiler and burner safety systems
- Offshore production skids
- Chemical-injection packages
- Produced-water treatment systems
- Vessel-mounted process plants
- Tank-level and overfill protection
- Machinery safety monitoring
Industrial Applications
- Oil refineries
- Petrochemical facilities
- Chemical-processing plants
- Power-generation facilities
- LNG terminals
- Pipeline compressor stations
- Tank farms
- Pharmaceutical plants
- Hydrogen-production facilities
- Water-treatment installations
- Steel and metal-processing plants
Redundant Configuration
The SAI143 can be installed as a dual-redundant module arrangement:
- Both modules receive the field-input signals.
- The safety system monitors the status of both modules.
- A module fault can be detected and annunciated.
- The healthy module maintains the input function.
- Maintenance can be carried out with reduced process interruption.
The base unit, terminal boards, software configuration and system revision must support the selected redundancy arrangement.
Important Field-Wiring Note
When the SAI143 is switched off or fails, the input-current loop may become open-circuited. Therefore:
- Do not share the current loop with another receiving instrument unless Yokogawa approves the arrangement.
- Provide the correct external field power supply.
- Confirm two-wire or four-wire transmitter configuration.
- Use the correct Yokogawa terminal board and connection cable.
- Follow the certified safety-loop wiring drawings.
