Voltage control relays are designed to protect devices with sensitive operating voltage from damage caused by mains voltage . https://youtu.be/Xoj744Soty0? Features: General Connection diagram for GK-04F network voltage for the devices which have sensitive working voltage. Using Manual and Working Principle Make the connections according to the diagram. Set the device according to the required electrical charge. if the voltages are the same as adjusted, relay led switches on and relay pulls. In this case contact, out is (NC) 1 pole. GK-04F type voltage controller relay doesn’t work if the phase sequence is incorrect. GK-01/04/04F type have related led for high and low voltage and phase cut off. Specification: GK-01/04/04F: High-Low voltage and time adjustable. GK-02: Low voltage and time adjustable. GK-03: High voltage and time adjustable. Switch off the device and release it from connections. clean the trunk of device with a swab. Don’t use any conductor or chemical that might damage the device. make sure the device works after cleaning. Package includes: 1 x VOLTAGE CONTROLLER RELAY GK-04F Phase failure Relay