AC Voltage 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


For over protection, under protection and combined under & over protection available in AC current AC voltage & frequency versions. Millivolt trip, DC voltage trip, Reverse Power, Phase sequence & Phase balance relays also available in our extensive range of protection relays..

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Selection Guide

M200-V1USingle phase under voltage
M200-V1OSingle phase over voltage
M200-V1CSingle phase combined voltage
M200-V33U3 phase 3 wire under voltage
M200-V33O3 phase 3 wire over voltage
M200-V33C3 phase 3 wire combined voltage
M200-V34U3 phase 4 wire under voltage
M200-V34O3 phase 4 wire over voltage
M200-V34C3 phase 4 wire combined voltage

Typical Applications

The M200 AC voltage protection relay provides voltage monitoring and protection in both single and 3 phase systems. Used in applications such as mains failure, regulation of power supplies and to protect voltage sensitive equipment. Under, over and combined over/under units are available. The relay operates when the externally adjustable trip point is reached.

An external differential control is provided with adjustment 1-15%. The differential ensures that the parameter being measured returns to % set above or below (depending on whether it is an under or over unit) the trip point before the relay returns to its original state. As is common with all the M200 relays, on over units the relay energises when the input signal exceeds the trip point. On under units the relay de-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.

Technical Specifications

Rated value Un:Single phase 57.8 < 500V three phase 100<500V
Frequency:50, 60 or 400Hz
Burden<2.5VA per phase single units
Burden<3VA per phase combined units
Overload1.5 x Un continuous 2 x Un for 3 seconds
Range underAdjustable 75% to 100% Un
Range OverAdjustable 100% to 125% Un
RepeatabilityBetter than 0.5% of full span
DifferentialAdjustable 1 to 15%
Operating timeTypically 200mS
AUXILIARYAll units self powered
Single UnitsApprox 0.4kg. 55mm case
Combined UnitsApprox 0.6kg. 100mm case

Ordering Information

Product CodeInputFreqOption
M200-V34U/D230V50V5 Sec t/d
  1. On all 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-V34U/D 5 seconds (state the fixed delay period).
  2. To prevent nuisance tripping when there is a slight variation in the voltage supply the following option is available. The external differential is replaced on the following products with an externally customer adjustable time delay. On these units the time delay is adjustable from 200mS to 10 seconds and the differential is fixed at 1%.

M200-V1X: Single phase under voltage
M200-V1Y: Single phase over voltage
M200-V1W: Single phase combined voltage
M200-V33X: 3 phase 3 wire under voltage
M200-V33Y: 3 phase 3 wire over voltage
M200-V34X: 3 phase 4 wire under voltage
M200-V34Y: 3 phase 4 wire over voltage
M200-V34W: 3 phase 4 wire combined voltage

3. Calibration at temperature other than 23ÂșC

Connection Diagrams

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