（1）.额定电压：电气设备的最大允许工作电压不应低于安装电路的最大工作

(1). Rated voltage: The maximum allowable working voltage of electrical equipment should not be lower than the maximum working voltage of the installed circuit. Under normal circumstances, the maximum allowable working voltage of 220kV and below electrical equipment is 1.15Ue. Therefore, generally, the rated voltage Ue of the electrical equipment is not lower than the rated voltage Uew of the power grid at the installation site: Ue≥Uew <br>(2). Rated current: The rated current In of the selected electrical equipment should not be lower than the maximum continuous operation of the installation circuit Current Imax: Ie≥Imax. When calculating the Imax of the circuit, the continuous working current under various operating modes in the circuit should be considered: the transformer circuit considers that the output remains unchanged when the voltage is reduced by 5%, so Imax = 1.05In; the bus circuit breaker circuit can generally take the total of the transformer circuit Imax; the outlet circuit should consider the Imax at the maximum load of the outlet.

(1) Rated voltage: The maximum allowable operating voltage of electrical equipment should not be lower than the maximum operating voltage of the installation circuit. In general, the maximum allowable operating voltage for electrical equipment 220kV and below is 1.15Ue. Therefore, generally can be in accordance with the rated voltage of electrical equipment Ue not less than the installed location of the power grid rating voltage Uew:Ue-Uew <br>(2) Rated current: The rated current of the selected electrical equipment is not lower than the maximum continuous operating current of the installed circuit, Imax: Ie-Imax. The Imax of the calculation circuit should consider the continuous operating current under the various modes of operation in the circuit: the transformer circuit considers that the output remains the same when the voltage is reduced by 5%, so Imax is 1.05In; The parent circuit breaker circuit generally preferably the total Imax of the transformer circuit;

(1) . rated voltage: the maximum allowable working voltage of electrical equipment shall not be lower than the maximum working voltage of the installation circuit. Generally, the maximum allowable working voltage of 220kV and below electrical equipment is 1.15ue. Therefore, generally, the rated voltage ue of electrical equipment can not be lower than the rated voltage of the power grid at the installation site Uew:Ue ≥Uew<br>(2) . rated current: the rated current in of the selected electrical equipment shall not be lower than the maximum continuous working current of the installed circuit Imax:Ie ≥Imax。 The IMAX of the calculation circuit should consider the continuous working current under various operation modes in the circuit: the output of the transformer circuit should be kept unchanged when the voltage is reduced by 5%, so IMAX = 1.05in; the total IMAX of the transformer circuit can be taken for the bus coupler circuit breaker circuit generally; the IMAX of the maximum load of the outgoing line should be taken into account for the outgoing line circuit.<br>