SAI143-S53/A4S10

The Yokogawa SAI143-S53/A4S10 is a 16-channel analog input module designed to receive 4-20 mA signals from field transmitters. It provides module isolation, individual channel configuration for 2-wire or 4-wire transmitters, and an integrated transmitter power supply for 2-wire connections. The specified assembly includes a pressure clamp terminal block with a surge absorber.

Functional Description

The SAI143 converts field current signals into input data for the Yokogawa control system. Its 16 input channels support a rated range of 4 to 20 mA, with a permissible input range of 0 to 25 mA. The 40 ms data update frequency defines the interval at which updated input values are made available to the system.

Module isolation separates the input signal circuits from the system side. The specified insulation withstand voltage is 1.5 kV AC for one minute between the input signal and system.

Transmitter Interface and Configuration

Each channel can be configured individually for 2-wire or 4-wire transmitter connections. The configuration is changed using setting pins, allowing different transmitter wiring arrangements to be handled within the same module.

In 2-wire mode, the module provides transmitter loop power. The specified supply voltage is at least 16.15 V at 20 mA and up to 26.4 V at 0 mA, with an output current limit of 25 mA. The transmitter power supply can be switched ON or OFF for all 16 channels simultaneously when the channels are configured for 2-wire operation.

Input Accuracy and Electrical Characteristics

For the SAI143-S version with style code S3, the rated accuracy is ±16 uA over an input range of 0.05 to 23 mA. This accuracy specification is different from earlier style-code versions, which have a narrower specified accuracy range. Temperature drift is ±16 uA per 10 deg C.

During power-on, the input impedance consists of a 250 ohm base value plus the voltage drop contribution of the internal input protection circuit. The maximum protection-circuit voltage drop is 0.45 V. The module input impedance varies with signal current, from approximately 272.5 ohm at 20 mA to 362.5 ohm at 4 mA. During power-off, the specified input impedance is at least 500 kOhm.

Terminal Connection and Surge Protection

The /A4S10 option specifies an analog pressure clamp terminal block with an integrated surge absorber, identified by Yokogawa as STA4S-10. This configuration provides the field wiring interface for the analog input signals.

The SAI143 supports pressure clamp terminals, MIL cable connections, and dedicated signal cables as external connection methods. The supplied /A4S10 configuration specifically identifies the pressure clamp terminal block rather than a signal cable interface adapter.

Technical Specifications

Parameter	Specification
Model	SAI143-S53/A4S10
Brand	Yokogawa
Product Type	Analog Input Module
Number of Input Channels	16
Input Isolation	Module isolation
Rated Input Range	4 to 20 mA
Permissible Input Range	0 to 25 mA
Input Impedance (Power-ON)	250 ohm + input protection circuit voltage drop contribution
Input Impedance (Power-OFF)	500 kOhm minimum
Rated Accuracy	±16 uA (0.05 to 23 mA, style code S3 or later)
Data Update Frequency	40 ms
Temperature Drift	±16 uA/10 deg C
Transmitter Power Supply	16.15 V minimum at 20 mA; 26.4 V maximum at 0 mA
Transmitter Output Current Limit	25 mA
Transmitter Configuration	Individual 2-wire/4-wire channel setting
Power Supply Control	ON/OFF control for all 16 channels simultaneously in 2-wire mode
Withstand Voltage	1.5 kV AC between input signal and system for 1 minute
Maximum Current Consumption	320 mA at 5 V system; 550 mA at 24 V system
External Connection	Pressure clamp terminal block
Terminal Block Model	STA4S-10
Surge Protection	Surge absorber included in terminal block
Operating Temperature	-20 to 70 deg C
ISA Environmental Classification	ISA Standard G3
Weight	0.34 kg

横河电机

Model Configuration

The ordering code identifies the module type, hardware configuration and terminal block option:

Code	Description
SAI143	16-channel, 4-20 mA analog input module with module isolation
-S	Standard type
5	Pressure clamp terminal block or MIL cable configuration, without explosion protection
3	ISA Standard G3 and temperature specification of -20 to 70 deg C
/A4S10	Analog pressure clamp terminal block with surge absorber
STA4S-10	Associated terminal block model

The -S53 configuration is the standard non-HART version. The suffix 3 specifies the ISA G3 environmental classification and temperature range; it should not be confused with the HART communication option, which uses the -H model designation.

Installation and Signal Compatibility

The SAI143-S53 is specified for use without explosion protection. Yokogawa also states that Zener barriers cannot be connected directly to this module. Where an intrinsically safe instrumented system is required, an isolation barrier must be used.

When checking an existing installation, verify the terminal block model, field transmitter wiring configuration and required safety barrier arrangement before replacing the module. The 2-wire transmitter power supply switching function is supported only under the specified hardware and software conditions.

Frequently Asked Questions

Q: Does the SAI143-S53/A4S10 support HART communication?

A: No. The -S designation identifies the standard version. Yokogawa specifies the -H version for HART communication functionality.

Q: Can the 16 input channels use different transmitter wiring configurations?

A: Yes. Each channel can be individually configured for 2-wire or 4-wire operation using the module setting pins.

Q: What is the function of the /A4S10 option?

A: It specifies the analog pressure clamp terminal block with a surge absorber, model STA4S-10. It identifies the supplied terminal connection configuration rather than a different analog input channel specification.

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