MH 9837

The frequency relays MK 9837N and MH 9837 are used for frequency monitoring of AC voltages. They are used for monitoring the output frequenc of frequency converters (/050) or for monitoring the rotor frequency of slip ring motors. Further areas of application are the monitoring of drives in crane systems, as well as the frequency monitoring of the supply voltage in rail vehicles.

• According to IEC/EN 60255-1
• Detection of over- or underfrequency of alternating voltage (adjustable function) (detection of over- and underfrequency see datasheet MK 9837N/5_0)
• Fast reaction time by measuring duration of cycle of input frequency
• Universal measuring input for AC-voltages of 15 ... 280 V as well as 30 ... 550 V
• As option with measuring input for inverters
• 4 ranges adjustable response value 1,5 ... 200 Hz or 5 ... 600 Hz
• Adjustable hysteresis
• Adjustable start up time delay 0 ... 50 s at function underfrequency
• Adjustable monitoring time for missing input signal at function overfrequency
• Response delay programmable via terminals 0 ... 100 s
• Alarm storing or auto-reset programmable via terminals
• Galvanic separation between measuring input, auxiliary voltage and output contacts
• MH 9837 available with wide input range for auxiliary supply (AC/DC 24 ... 60 V or AC/DC 110 ... 230 V)
• 2 changeover contacts, closed circuit operation
• Open circuit operation on request
• LED indication for auxiliary voltage, measuring voltage and alarm status
• MH 9837.12/008: With galvanic separated analogue output (current/voltage) and 11 step LED chain for the actual frequency
• Device available with 2 response values and seperately controlled outputrelays for under- and overfrequency see MK 9837N/500
• 2 possible compact designs:
  MK 9837N: Width 22,5 mm
  MH 9837: Width 45 mm