Product Description

The SDV521-S33 S2 is a high-capacity safety digital output module designed for the Yokogawa ProSafe-RS Safety Instrumented System (SIS). Unlike standard high-density modules, it provides 4 isolated current-source output channels, each capable of delivering up to 2 A, making it ideal for heavy-duty field devices such as large solenoid valves and high-power signaling equipment that exceed standard 0.6 A module capacity.

Manufactured in Japan, the SDV521-S33 S2 meets SIL3 safety certification standards, featuring continuous hardware integrity checks. The S2 revision indicates an optimized hardware build with enhanced thermal stability for sustained high-current operation. The module can be configured in redundant pairs for maximum process availability.

Technical Specifications

Industrial Application

The SDV521-S33 S2 is used in heavy industrial sectors where high-current actuation is required:

• Power generation facilities

• Petrochemical and chemical refineries

It is ideal for driving high-wattage actuators and executing energize-to-trip safety functions where standard 0.6 A modules are insufficient, ensuring reliable operation in Emergency Shutdown (ESD) scenarios.

Frequently Asked Questions

Why is the minimum load current 100 mA?
The SDV521-S33 S2 is a high-power driver. A minimum load of 100 mA is required for its internal pulse-test diagnostics to accurately monitor line faults. Loads below this threshold may trigger false open-loop alarms.

Can this module be used in a redundant configuration?
Yes. In a dual-redundant setup, two SDV521-S33 S2 modules operate in parallel to ensure that, if one module fails, the connected final control elements continue to operate safely without interruption.