Features:5A over-current protection sensor module.Uses current transformer to collect the AC signal to achieve the relay over-current signal output within 0-5A. Relay pull while over-current, relay released while not over-current. Users can use the relay COM, NC, NO three ports to control the external circuit on and off, in order to achieve over-current protection.Over-current signal setting critical point is adjustable.Specification:Type: 5A 5V Relay ModuleWorking voltage: DC5VWorking current: <20MAOperating frequency range: 20Hz-400HzOutput mode: switch signal outputMaximum detection wire diameter: 5.2mmMounting hole: hole diameter is 3mm, hole pitch is 52.5mmOperating environment: -40 - 85Current detection range: AC0.3A-5ABoard size: Approx. 38 * 44mm / 1.5 * 1.7inWeight: Approx. 27gPackage list:1 * ModuleFunctions:Current detection resolution can change the parameter of resistance parameters.Output over-current switching signal output.Over-current signal setting critical point is adjustable.Board Description:VCC: Operating voltage positive;GND :Operating voltage negative;NO: Normally open, the relay pulls before the NO and COM disconnect, short-circuit after the suction;COM: common, relay common interface;NC: Normally closed, the relay before the NC and COM short-circuit, after pull off. Using Instructions:By setting the potentiometer to set the overcurrent protection point, the clockwise adjustment can reduce the detection current.As bellows:1. Measured the wire through the current transformer , connect VCC and GND to DC5V power supply;2. Adjust the potentiometer, when you hear the sound of the relay pull (can be measured with a multimeter, to see if COM and NO was turned on, and if connected to the relay means activated), then reduce or cut off the current flowing that through the tested wire , if the relay release at this time that over-current protection point has been identified (can use multimeter to see if COM and NC was connected, if connected to the relay means been released);3. When reduce or cut off the current flowing through the wire , the relay is not released, will still need to continue to adjust the potentiometer to find the over-current protection point. .