Air Circuit Breakers


SFA and SDA series air circuit breaker is suitable for the circuit of AC 50Hz/60Hz with rated service voltage 400V, 690V and rated service current up to 4000A. It is mainly used to distribute electric energy and protect circuits and electric equipment against over-load, under-voltage, short-circuit and single-phase earthing fault. With intelligentized and selective protection functions, the breaker can improve the reliability of power supply, and avoid unnucessary power failure. The breaker is applicable for power stations, foctories, mines (for 690V) and modernhigh-buildings, especially for the distribution system of intelligentized building.

Main Feature

According to the mounting: fixed and draw-out According to the poles: three poles, four poles According to the operation ways: motor and manuel Operation Conditions Ambient air temperature a) Maximum not exceed +40°C b) Minumum not lower than -5°C c) 24h average value not exceed +35°C

Note: Ambient air temperature is -10°C or -25°C and users should declare to manufacturer when put the order; ambient working condition is between -25°C and +40°C. User should negotiate with manufacturer. Elevation ? 2000M Atmosphere condition: relative humidity is not exceeding 50% at the maximum ambient temperature of +40°C With lower temperature, higher humidity would be permitted, but the lowest average tempature in a month not exceeding +25°C during the moistest month, and the maximum monthly average relative humidity not exceeding 90% in that month,and giving consideration to the dews on the goods surface, which would appear due to temparature change.