SAFEMASTER S Speed and frequency monitor UH 6937 Safe, sensorless drive monitoring With the speed and frequency monitor UH 6937 from the SAFEMASTER S Series, DOLD offers an efficient, economic solution for safe, sensorless drive monitoring. Monitoring the output frequency of traction converters is just one of the many different ways to use this component. In case of over- or under-frequency, or if the frequency is outside the set window, the frequency monitor shuts off safely, proving its benefit over frequency converters with integrated safety functions in any application where simplicity, flexibility, and safety are required. As an additional protective measure, the device can be adapted to an application by pressing just a few buttons. With the appropriate wiring, the device can offer the safety functions STO (safe torque off), SOS (safe operation stop), SLS (safely limited speed), SSM (safe speed monitoring) and SSR (safe speed range) in accordance with EN 61800-5-2. And it does all this up to Performance Level (PL) e or Safety Integrity Level (SIL) 3. With the help of ergonomically shaped buttons on the front, and a lit LCD display, you can quickly and easily access parameters relevant for the application, such as monitoring functions, delay times, and frequency ranges for up to four operating modes – all without a PC. Your advantages For safety applications up to cat. 4 / PL e or SIL 3, UL-listed Simple, time-saving start-up without a PC Sensorless and easy to upgrade Comprehensive diagnostic function Bypass option for frequency monitoring (Muting) Up to 4 operating modes can be activated (e.g. automatic, set-up, or service mode) Over- or under-frequency or frequency range monitoring For frequencies up to 1200 Hz and voltages up to AC 690 V

Speed and frequency monitor UH 6937 Technical features Over- or underfrequency or frequency range monitoring for single phase or three-phase alternating voltages User-friendly front display: - for comfortably setting parameters through menus - for target and actual value displays in Hz Quick response time using cycle duration measurements of input frequency Adjustable hysteresis Adjustable release delay of 0 ... 100 s Adjustable start-up bypass time of 0 ... 100 s Adjustable alarm delay of 0.1 ... 100 s Manual or auto-reset Galvanic separation of measuring input, auxiliary voltage, and output...