Work principle and performance:

  Work voltage 150V-300V, 50Hz.

  Within the range of voltage 165V-260V the relay is opened and the red lamp is on.

  When voltage is lower than 160V or higher than 260V, the relay is closed and red light flashes.

  The delaying time of the relay is 2 seconds

Strength of appliance：

  Apply 1500VAC voltage between the live part and shell with leaking current of 5mA for 1 minute, it has no breakdown.

Work principle:

  There is two switches and terminal 1, 2, 3 above the double controller .Of it, terminal 1 and 3 are often closed and terminal 1 and 2 are often opened. When the water level in the vessel rises, the floater will float upward, so terminal 1 and 3 are opened and terminal 1 and 2 are closed. When the water level drops under the standard water level, terminal 1 and 3 are closed and terminal 1 and 2 are opened and the electrical appliance can work normally.