Frequency Relay IL 9837 The frequency relay IL 9837, SL 9837 can be used to monitor the frequency of AC voltage systems, rotor frequency of slip ring motors, control/monitoring of motors on cranes, monitoring the output frequency of inverters (IL9837.11/500). Features . According to IEC/EN 60255-1 . Overfrequency or underfrequency monitoring of AC voltages . Adjustable response value fmin. or fmax 5 ... 200 Hz or 15 ... 600 Hz . Adjustable hysteresis . Large voltage range of the measuring input (nominal voltage AC 24 ... 440 V) . De-energized on trip . LED indication for auxiliary voltage, measuring voltage and contact position . 1 changeover contact . As option for frequency inverters with a range of 1 … 300 Hz . 2 changeover contacts available on request . As option adjustable start-up delay available . Energized on trip function available on request . Devices available in 2 enclosure versions: IL 9837: depth 58 mm, with terminals at the bottom for installation systems and industrial distribution systems according to DIN 43880 SL 9837: depth 98 mm, with terminals at the top for cabinets with mounting plate and cable duct . 35 mm width Technical specifications Width: 35mm Operate delay: Yes Enclosure design: Distribution board 1- / 3-phase: 1 Standard measuring range: 5 - 200 Hz Measuring range max.: 300 Hz Output contacts: 1 C/O contact Auxiliary voltage required: Yes Type: IL 9837 Manufacturer: E. Dold & Söhne GmbH & Co. KG Type: IL9837.11 5-200HZ UH AC230V Art. No.: 0056555