air switch, weigh recloser again, low-pressure breaker. The principle is: Exceed rated electric current, short circuit when working electric current, break pressure wait for a circumstance to fall, cut off circuit automatically.

Current, the switch of knife having brake with domestic common master switch matchs porcelain to insert insurance (already was washed out) or air switch (the small-sized breaker that takes protection of leakage of electricity) . At present the family uses the air switch of DZ series, have the following model commonly / norms: The norms such as C16, C25, C32, C40, C60, C80, C100, C120, among them C expresses to buckle electric current, take off namely electric current, for example C32 states take off electric current is 32 how, water heater of general installation 6500W should use C32, the sky that water heater of installation 7500W, 8500W wants to use C40 leaves.