Dold Introduces New Rotation Direction Feature to UH 6937 Frequency Monitor
Dold has introduced safety-rated directional control and regulatory compliance to the UH 6937 speed and frequency monitor, making it an ideal solution for applications where safety is critical.
Dold, a company known for its extensive catalog of safety and automation solutions, has recently announced their latest improvement to their lineup of products, the frequency monitor UH 6937. The innovative solution from Dold is equipped with features that offer contactless speed monitoring for motors, with the new improvement being the introduction of a safety-rated direction of rotation detection.
Dold’s sensorless UH 6937 monitors the speed and frequencies of motors, and is now equipped with a safe direction of rotation monitoring feature. Image used courtesy of Dold
Dold’s UH 6937 Frequency Monitor
The frequency monitor device by Dold is designed to detect the frequency of the AC supply and the speed of the rotation of motors. Motors with 3-phase alternating currents (AC) can have their rotary directions easily observed through the motor's respective phase sequence with the innovative solution.
The safety feature works so that when the movement of the motor is not in the desired direction, it switches output contacts so the motor can be brought to a swift, controlled stop. Equipped with terminal blocks that can be plugged, screw terminals, and pluggable cage clamp wire, the installation and setup of the device is simple and fast. Found in the SAFEMASTER S series, the UH 6937 speed sensor have variants with maximum response value ranging between 600 Hz to 1200 Hz, with some variants equipped with an analog output and different modes of frequencies.
The product series also allows for simple integration into existing drive systems as there is no need for a PC, saving installation time.
User-Friendly Features of the UH 6937 Speed Sensor
Equipped with a comfortable on-screen configuration menu guide, the UH 6937 frequency monitor’s front-side display offers features for easy operation. Parameters like the direction of rotation and frequency can have both the actual and setpoint values displayed on the interface.
The monitor also has an adjustable reset delay function of up to 100 s that allows for the monitoring of frequency and a start-up time delay that can be adjusted to handle tolerance during switching periods for direction monitoring. For convenience, it is also equipped with a manual and auto-reset function, two solid-state contacts for simple status monitoring, and LED indicators for output monitoring.
Dold provides various safety relay solutions for monitoring speed, direction, and motor frequency. Image used courtesy of Dold
UH 6937 Safety and Compliance
The frequency monitor UH 6937 is equipped with four modes of operation to ensure safety and can be configured differently: under-frequency, over-frequency, direction of rotation, and window limit range. When there is a critical error or violation in parameter settings, the safety monitor switches contact states to provide a controlled stop until the fault is corrected.
To ensure that the new frequency monitor finds its use in safety-critical applications, it has gained UL approvals and safety compliance certifications. While keeping the prior safety-related characteristics, PL e / Cat. 4 and SIL 3 for speed and frequency monitoring, the direction of rotation monitoring satisfies SIL 2 according to EN 61508 and EN ISO 13849-1 in PL d / Cat. 2.
Target Applications of the UH 6937
Many industries will likely benefit from this new innovative solution by Dold, as the applications span across those where monitoring the direction of rotation is essential. Industries with automated processes, machine tools, and components like compressors, wind turbines, and cranes can find the solution useful, as any unintended directional change can cause damages and downtime, which can be costly to repair.
As the demand for efficient frequency and motor RPM monitoring solutions grows, the emergence of innovative solutions like Dold’s UH 6937 will indeed infiltrate the market as it boasts benefits of safety integration, flexibility, and simplicity as compared to conventional frequency inverters.
