3.0.1　The electrical equipment shall be classified into critical electrical equipment and general electrical equipment based on the following requirements:

1　Critical electrical equipment:including the electrical equipment that is rated in voltage levels of 110kV and 220kV or used to supply power to the first grade loads in enterprises and the electrical equipment that is required to secure power supply in case of earthquake.

2　General electrical equipment:including the equipment other than those specified in Item 1.

3.0.2　Visual examination shall be performed for aseismatic appraisal of electrical equipment，and the following requirements shall be complied with:

1　The equipment itself shall be free of any damage，and the porcelain insulators shall be free of any crack.

2　The electrical connections shall be reliable，the bolting shall be in good conditions，and the nuts shall not be loose.

3　The connections between the equipment and foundation/the support structure shall be firm.

4　The welds shall be free of any crack，and the metal parts shall be free of any severe corrosion.

5　The equipment supporting structures and attachments shall be free of any deformation or damage.

3.0.3　The seismic effect may be characterized by the following ground motion parameters for area where the electrical equipment is installed:

1　The design basic acceleration of earthquake ground motion or aseismatic precautionary intensity.

2　The characteristic period of ground motion.

3.0.4　The correlation between design basic acceleration of earthquake ground motion and aseismatic precautionary intensity is shown in Table 3.0.4.

3.0.5　Aseismatic calculation shall be provided for the power transformers，vertically installed threephase reactors and arrestors，circuit breakers and porcelain bushings for one of the following cases:

1　The area where the design basic acceleration of earthquake ground motion is 0.20 g and above.

2　The areas where the design basic acceleration of earthquake ground motion is 0.10 g and 0.15 g and the voltage level is 110kV and 220kV.

3　The area where the design basic acceleration of earthquake ground motion is 0.15 g and the height of floor or support on which the electrical equipment is installed is higher than 2.0m.

3.0.6　Aseismatic calculation may not be provided for the following electrical equipment；however，aseismatic appraisal shall be provided for the fixing methods and the construction of the electrical equipment，and corresponding aseismatic measures shall be taken.

1　The capacitor groups（cabinets），battery banks（cabinets），switchgear cabinets，converter cabinets，control（relay）panels，DC panels，emergency power supply units，gas insulated switchgears and other electrical equipment.

2　The racks used to install the electrical equipment.

3　The electrical equipment other than those specified in Article 3.0.5 of this standard.

3.0.7　The earthquake action of the critical electrical equipment shall be calculated by one level higher than the design basic acceleration of earthquake ground motion for the area where the equipment is installed，and the seismic measure shall be provided one level higher than the aseismatic precautionary intensity specified for this area.If the aseismatic precautionary intensity is 9 degree，the design basic acceleration of earthquake ground motion used to calculate the earthquake action may not be further increased，the aseismatic measures may be properly strengthened.

3.0.8　If the electrical equipment fails to meet the aseismatic appraisal requirements，aseismatic measures shall be taken or shock-absorbing measures shall be taken in accordance with Appendix A of this standard.

3.0.9　Unless otherwise specified in this standard，the design allowable stress used in aseismatic calculation for electrical equipment shall be selected in accordance with the following requirements:

1　The design allowable stress for elastic materials may be 1.4 times the allowable stress of the materials at design temperature，but it shall not be larger than 0.9 time the yield strength of the materials at design temperature.

2　The design allowable stress for brittle materials may be 1.2 times the design tensile strength of the materials or 0.6 time the breaking stress of the materials at design temperature.

3.0.10　Various electrical equipment shall be reliably fixed onto the foundation，bases or racks，and the equipment anchor bolts or welding strength shall meet the aseismatic precaution requirements.

3.0.11　In the areas where the design basic acceleration of earthquake ground motion is 0.20 g and above，the power distribution equipment installed at high positions or on multi-layers should be relocated on lower positions or aseismatic measures should be taken，and the tubular bus should be suspension installed.

3.0.12　Flexible conductors should be used to connect the electrical equipment lead wires and equipment，and proper length margin shall be provided for the flexible conductors.If rigid bus is used for connection，flexible fitting shall be provided for transition. bx9AAXYqrVUC2nsCtrNMI06R95KjT8RCOXWqHBdujRcC5fHUIvqIZnBuJ2YWrptF