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Withstand voltage of communications equipment


(1) Withstand voltage between the line and the ground

The withstand voltage between the communications line of a piece of communications equipment and the ground is generally designed to be DC500V – 1 min., and that between the AC power supply terminal and the ground AC1500V – 1 min. Examples of the results of withstand voltage tests conducted using impulse generators on equipment designed and manufactured to these withstand voltage specifications show that actual impulse withstand voltage is around 2 to 3kV on the communication line side, and around 5 to 6kV on the AC power supply side. The withstand voltage in recent electronic equipment has become weaker due to the use of IC, etc.

(2) Withstand voltage between lines

The withstand voltage between lines in communication line terminals differs greatly depending on the type of equipment. The impulse withstand voltage in the coils and contacts used in conventional telephones and relays is around 2 to 3 kV, but in equipment that uses electronic devices such as transistors and IC, the withstand voltage is often anywhere between 10 to 100V.

(3) Withstand voltage between circuits, or between I/O

As with the withstand voltage between lines, there are impulse withstand voltages of between 2 to 3kV, where the equipment is insulated by an insulation transformer, etc., and the DC withstand voltage can rise above 500V, and those of between 10 and 100V, where there is direct connection to the circuits.

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