Dold Frequency Monitoring Relay, DPDT, 15 → 280V ac, DIN Rail / 1812791

Detection of over- or under frequency of alternating voltage (adjustable function) 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 Adjustable hysteresis Adjustable monitoring time for missing input signal at function over frequency 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 separately controlled output relays for under- and over frequency see MK 9837N/500