Dold Industries Ltd

11 Hamberts Rd. Blackall Ind. Estate
South Woodham Ferrers
GB-Essex, CM3 5UW
UH 6937

Speed and frequency monitor

UH 6937


Auxiliary voltage

Terminal type

Approvals and Markings


  • 0066820
  • UH6937.02PS/61 DC24V
The speed and frequency monitor UH 6937 provides safe frequency monitoring of AC voltages. It is... more

Product description

The speed and frequency monitor UH 6937 provides safe frequency monitoring of AC voltages. It is used to monitor the output frequency of inverters or the rotor frequency of slipring motors. An other application area is the monitoring of motors in crane plants. Using the front side display the parameters can be easily and comfortably adapted to the individual application or changed when necessary.

Technical specifications

Width: 45 mm
Classification: Sensorless
Cat. / PL acc. to EN ISO 13849-1: 4/e
SIL CL acc. to IEC/EN 62061: 3
Nominal voltage: DC
Thermal current Ith max.: 8 A
1- / 2-channel: 2
Connection: Pluggable screw terminals, Pluggable cage clamp terminals, Pluggable cage clamp terminals 2-wire
Indicator contacts: 2 Semiconductor monitoring outputs
Measuring motor voltage max.: 690 V
Approvals: UL
Forcibly guided output contacts max.: 2 NO contacts
Type: UH 6937


  • For safety applications up to PL e / Cat. 4 and SIL 3
  • Simple and time saving setup without PC
  • Comfortable, menu guided configuration via frontside display
  • Reducing interruption time in production by extensive diagnostic functions
  • Easy to integrate in existing drive applications
  • For inverters up to 1200 Hz
  • Possible languages: english, german, french


  • According to
    - Performance Level (PL) e und category 4 to EN ISO 13849-1
    - SIL-Claimed Level (SIL CL) 3 to IEC/EN 62061
    - Safety Integrity Level (SIL 3) to IEC/EN 61508
    - Safety Integrity Level (SIL) 3 to IEC/EN 61511
  • Over-, underfrequency or window monitoring of single or 3-phase in AC systems
  • Integrated user friendly frontside display
    - Comfortable, menu guided configuration
    - For set point and actual value of Hz
  • Fast reaction time by measuring duration of cycle of input frequency
  • Universal measuring inputs for AC-voltages of 8 ... 280 V for single-phase monitoring as well as 16 ... 690 V for single- and 3-phase monitoring
  • Suitable for inverters
    - Variant /0_ _ : 1 ... 700 Hz
    - Variant /1_ _ : 1 ... 1200 Hz
  • Adjustable hysteresis
  • Adjustable reset delay function from 0 ... 100 s
  • Adjustable start up time delay from 0 ... 100 s
  • Adjustable alarm delay from 0.1 ... 100 s
  • Manual or auto-reset
  • galvanic separation between measuring input, auxiliary voltage and output contacts
  • 2-channel function
  • Forcibly guided output contacts
  • LED-indicators and 2 semiconductor monitoring output
  • Width 45 mm
  • With pluggable terminal blocks for easy exchange of devices
  • Variant /_ _1:
    - it is possible to set a variety of response parameters by means of a 4 bit selection facility from an overriding control unit;
    - analog output (2V to 10V) corresponding to the current speed;
    - the possibility of overriding the speed by a supervisory function (muting);
    - adjustable switchover time from 0 ... 100 s