The Pilz S1MN 240VAC 2C/O (part number 840420) is a robust monitoring relay developed for safety and automation systems where reliable supervision of resistance values and operating conditions is essential. As part of Pilz’s trusted range of monitoring devices, it ensures compliance with industrial standards while providing flexibility, precision, and safety for diverse applications.

This unit is powered by a 240 V AC supply, making it suitable for direct integration into standard industrial power networks. By supporting line voltage operation without the need for auxiliary supply adjustments, it simplifies system design and reduces installation complexity. With a low power consumption of 3.5 VA, the device is energy-efficient, enabling continuous operation with minimal energy impact.

One of the defining features of the S1MN is its ability to provide precise resistance monitoring. With a response threshold of 3.6 kΩ ±10 %, the relay can detect deviations that indicate abnormal or unsafe conditions in connected circuits. This level of sensitivity ensures operators and system designers are alerted to potential faults before they escalate into failures or hazards.

Equipped with two changeover (C/O) contacts, the S1MN offers flexible configuration options. These outputs allow the relay to be integrated into a variety of monitoring and safety circuits, supporting both signalling and switching functions. The dual contacts also provide redundancy, enhancing reliability in safety-critical applications where fault tolerance is required.

The device is designed for industrial durability and compliance, making it suitable for a wide range of automation and monitoring tasks. Whether supervising electrical circuits, detecting resistance changes in sensor systems, or ensuring safety functions remain within specified parameters, the S1MN contributes to maintaining high standards of reliability and operator protection.

Practical applications include monitoring in motor circuits, resistive load supervision, and safety systems where resistance thresholds are used as an indicator of system status. Its role is particularly valuable in environments such as process automation, machine building, and energy distribution, where maintaining safe electrical parameters is vital to productivity and safety.

Built in line with Pilz’s commitment to quality, the S1MN 240VAC 2C/O is engineered for long service life under continuous operation. Its construction ensures consistent performance despite exposure to vibration, thermal variation, and other challenges typical of industrial environments.

In summary, the Pilz S1MN 240VAC 2C/O (840420) is a versatile and dependable monitoring relay that provides precise resistance supervision and flexible switching capabilities. With its 240 V AC operation, dual C/O contacts, 3.6 kΩ response value, and low energy consumption, it offers a reliable and efficient solution for safeguarding machines, processes, and operators in a wide variety of industrial settings.