The Pilz S3UM 24VDC UM 400/440VAC H40 (part number 837271) is a high-quality monitoring relay designed to provide safe and reliable supervision of three-phase electrical systems. As part of Pilz’s trusted S-series of monitoring devices, this relay offers a robust solution for detecting voltage irregularities and ensuring the continued safety and efficiency of industrial equipment.

Operating on a 24 V DC supply, the device is fully compatible with standard control system voltages used across modern automation environments. With a power consumption of only 1.5 W, it offers energy-efficient operation, making it a cost-effective choice for systems where multiple monitoring relays are deployed. This efficiency not only reduces energy usage but also helps extend the life of associated components by minimising electrical load.

The S3UM 24VDC UM 400/440VAC H40 is specifically engineered to monitor system voltages in the 400–440 V AC range. This makes it suitable for use in a wide variety of industrial applications, including three-phase power distribution, motor control centres, and heavy machinery. By continuously monitoring voltage levels, the device can detect under- or over-voltage conditions and trigger protective responses, helping to prevent equipment damage, downtime, and safety hazards.

The device is manufactured in compliance with EN 60947-4-1, a key international standard for low-voltage switchgear and control gear. This ensures the S3UM meets stringent requirements for reliability, safety, and durability, making it a trusted component in safety-critical electrical installations. Its suitability for utilisation category AC/DC1 further underlines its versatility and reliability in a range of operating conditions.

Built for industrial resilience, the monitoring relay can withstand the electrical and environmental stresses typical of automation environments. Its robust construction ensures consistent performance even under fluctuating loads, vibration, and temperature variations. This durability translates to longer service life and reduced maintenance, making it a dependable part of any safety or monitoring system.

In practical applications, the S3UM 24VDC UM 400/440VAC H40 is used to supervise three-phase motors, power supply systems, and production equipment. By ensuring voltage remains within the specified range, it supports both machine protection and operator safety. The device is particularly valuable in industries such as automotive, process control, packaging, and energy distribution, where reliable monitoring is critical to maintaining system uptime and avoiding costly disruptions.

In summary, the Pilz S3UM 24VDC UM 400/440VAC H40 (837271) is a robust and efficient monitoring relay that combines precise voltage supervision with compliance to international standards. With its 24 V DC operation, low 1.5 W consumption, wide monitoring range, and durable design, it provides engineers and operators with a reliable solution for ensuring safe and efficient operation of three-phase electrical systems.