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 unnecessary power failure. The breaker is applicable for power stations, factories, mines (for 690V) and modern high-buildings, especially for the distribution system of intelligentized building.

SIGMA ACBs are produced as fixed and drawable type from 630A up to 4000A according to the TS EN 60947-2 and CE standards. There is auxiliary Contact 2NO+ 2NC on each sigma ACB.

Air circuit breakers could be coupled with wide range of accessories: aux. and signal Contacts, all kind of releases, mechanical interlocks, shunt trips and motor operator.

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 temperature 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 temperature change.