DL/T 402-1999 in English

Scope

These ordering technical conditions apply to three-phase circuit breakers in indoor and outdoor three-phase systems with rated voltage 3 to 500kV and frequency 50Hz and single-phase circuit breakers in single-phase systems. This standard does not apply to circuit breakers in places with fire, explosion hazard, chemical corrosion and severe vibration. Note: Requirements beyond this standard shall be negotiated between the user and the manufacturer. If the requirements of fully enclosed combined electrical appliances, sulfur hexafluoride circuit breakers, vacuum circuit breakers, factory power and generator circuit breakers exceed the requirements of this standard, they will be separately specified in the corresponding special standards.