Frequency Protection Relay

Frequency Protection Relay


DIN rail mounting protection relays for use in single and three phase systems. Available in 55mm x 112mm or 100 x 112mm DIN rail cases

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Selection Guide

M200-F1USingle or 3 phase under frequency
M200-F1OSingle or 3 phase over frequency
M200-F1CSingle or 3 phase combined under and over frequency

Typical Applications

The M200 series frequency protection relays are designed to monitor the frequency of a system and if the frequency deviates outside the customer adjustable preset limits, the relay will operate. Typically used in protecting generators against under or over speed, this is achieved as speed is proportional to frequency.

Other uses such as monitoring mains power supplies, computer supplies etc. The user is provided with adjustment of both the trip point of frequency being monitored and the differential. As is common with all the M200 relays, on over units the relay energises when the input signal exceeds the trip point. A red LED indicates the state of the relay, whilst a green LED indicates the condition of the power supply. The frequency relays monitor their own power supply so no auxiliary power is required.

Technical Specifications

Rated value Un57.8<500V ±25%
Rated frequency50/60/400Hz
Burden< 2.5VA
Overload1.5 x Un continuous 2 x Un for 3 seconds
Range 50Hz nominalAdjustable 40 to 60Hz
Range 60Hz nominalAdjustable 50 to 70Hz
Range 400HzAdjustable 360 to 440Hz
Differential 50 & 60HzAdjustable 0.3 to 3Hz
Differential 400HzAdjustable 3 to 30Hz
RepeatabilityBetter than 0.5% of full span
Operating TimeTypically 200ms
AUXILIARYAll units self powered
Single unitsApprox 0.4kg. 55mm case
Combined UnitsApprox 0.6kg. 100mm case


1On all of the above units an internally set time delay is available for any value between 1 & 10 seconds. To order use the above codes adding a D at the end of the code. e.g M200-F1U / D7 seconds (state the fixed delay period).
2AC auxiliary in range 57.7 to 480 volts
3To prevent nuisance tripping when there is a slight variation in the frequency the following option is available. The external differential is replaced with an external time delay. On these units the time delay is adjustable from 200mS to 10 second, and the differential is fixed at 1%.
M200-F1X: Single or 3 phase under frequency
M200-F1Y: Single or 3 phase over frequency
M200-F1W: Single or 3 phase combined frequency
4Calibration at temperature other than 23ºC

Connection Diagrams

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