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Small knowledge in explosion-proof certificate: The meaning of U and X is indicated after the explosion-proof certificate number

1. The symbol "U" in the explosion-proof certificate represents

A symbol used to represent Ex components. The so-called Ex component indicates that this component is only a part of the explosion-proof structural type and cannot be used alone. It can only be combined with other components or parts to become a complete explosion-proof equipment. This component is often a universal accessory for manufacturers.

Generally, "U" is added after the explosion-proof certificate number of this Ex component.

For example: “CNEx16.8999U”

2. The symbol "X" in the explosion-proof certificate represents

A symbol used to indicate special safety usage conditions or limiting conditions. For example, requirements for limiting the installation locations of equipment, selection of incoming cables, and explanation of the impact energy resistance of the casing.

Usually, an "X" is added after the explosion-proof certificate number, and the restriction conditions are explained in the remarks column. For example, the certificate of conformity for explosion-proof lamps CNEx16.6788X states in the remarks column that "this lamp is only suitable for vertical downward installation".

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