Low-voltage switchgear shall set up a good protection circuit, namely, cupboard door, cabinet put oneself in another's position, drawer, etc can all metal parts of current-carrying loop, and to make the protection circuit is continuous.
Low-voltage complete switch equipment should be mutual effectively through direct connection, or through mutual effectively completed by protection conductor connection in order to ensure the continuity of the protection circuit.To determine the sectional area of protection conductor, should consider to cooperate with protection device action, within the scope of the protection device operating current and time, will not damage to protect the continuity of a conductor or destroy it, its specific requirements are as follows:
1) as a part of equipment from the shell, the equipment should not be cut off the rest of the protection circuit.
2) if the withdrawable parts are equipped with a metal support surface, and they put pressure on support surface is large enough to argue that the bearing surface to ensure the continuity of protection circuit, from the connection to the separation position, withdrawable parts of the protection circuit should keep its effectiveness.
3) in the cover plate, door, shutter and similar parts above, if there is no electrical equipment installation, usually of metal screws and metal hinge is considered enough to ensure the continuity of electricity.If equipped with a voltage value more than limit on its appliance, should adopt protection conductor connect these components and protection circuit, the protection of the cross-sectional area of the conductor depends on its electrical power leads a maximum of cross-sectional area.Designed for this purpose the equivalent electrical connection (such as sliding contact, anti-corrosion hinge) is considered to be meet the requirements.
4) equipment in the protection circuit design of all components should be enough to them to inherit the equipment installation site may meet the maximum thermal stress and electric stress.
GCS draw-out switch cabinet is packaged, and shipped on electrical components installed in galvanized frame, frame with modulus hole galvanized frame connection, a lasting conductive ability.Install the framework and cabinet put oneself in another's skeleton for galvanized parts, so has the very good grounding protection performance.
For the activities of the high and low voltage switchgear components, such as cupboard door, instrument, the drawer structure components and high voltage switch cabinet of the car, etc., must set up to protect circuit device in a row, and protection of grounding bus bar connection, ensure the continuity of the protection circuit.
