2　General Provisions

2.0.1　The layout of switchgear and selection of conductors，electrical equipment，and gantries shall meet the safety requirements during normal operation，installation and maintenance and in the event of shortcircuit and overvoltage under local ambient conditions，and shall accommodate the system capacity planned for the coming 10-15 years.

2.0.2　The phase sequence of individual circuits of switchgear should be consistent with each other.It may be in the order of phases A，B and C when facing the outgoing lines and viewing from left to right，far to near，and top to bottom.Indoor rigid conductors and outdoor busbar bridge shall be colored accordingly.To be specific，lines of phases A，B and C shall be colored yellow，green，and red respectively.Expansion works shall have a phase sequence the same as the existing switchgear.

2.0.3　For arrangement sequences of busbar in 66-110kV switchgear，the busbar at transformer side should be busbar I，and that at the line side busbar II.For switchgear in double-layer arrangement，the busbar on the lower layer should be busbar I and that on the upper layer busbar II.

2.0.4　Outdoor open type 110kV switchgear shall not be maintained when being energized.

2.0.5　For 66-110kV open type switchgear，busbar arresters and voltage transformers should share one group of disconnectors.

2.0.6　For 66-110kV open type switchgear，earthing switches should be provided at the line side of line disconnectors and at the circuit breaker side of disconnectors mounted at both sides of a circuit breaker.Gas-insulated metal-enclosed switchgear should be equipped with isolation breaks.

2.0.7　For 66-110kV open type switchgear，earthing switches shall be installed for each section of busbar.

2.0.8　For 66-110kV open type switchgear，voltage transformers should be equipped on three phases of each group of main busbars.When it is necessary to monitor and detect the presence of voltage at line side，voltage transformers should be installed on one phase at the outgoing line side.

2.0.9　For 66-110kV switchgear，all circuits installed with circuit breakers shall be equipped with current transformers.

2.0.10　Blocking devices shall be provided among disconnectors of indoor and outdoor switchgear，the corresponding circuit breakers and earthing switches.When the indoor switchgear is arranged at low level，blocking devices shall be provided to prevent accidental access to energized bay.

2.0.11　The layout of oil-filled electrical equipment in switchgear shall allow for safe and convenient observation of oil level and temperature under energized conditions，and facilitate oil sampling.