Power Automation Sweden AB

Cylindervägen 8
13152 Nacka Strand

Safe, sensorless drive monitoring

Speed and frequency monitor UH 6937

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.

Advantages and customer benefits

  • 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