santo gantry crane

2013年7月31日星期三

Crane electrical equipment enclosure must be grounded What are the requirements?

  1 single girder  gantry crane  leakage protection of electrical equipment protected by enclosure must be grounded its ground generally have the following requirements:

     (A) the protection of electrical equipment should be implemented separately grounded metal enclosure.

     (2) single girder  hoist gantry crane  electrical equipment are protected grounded metal enclosure, preferably with power neutral ground apart.

     (2) When unable to meet the above requirements and must adopt a common ground approach, they shall comply with the following requirements:

     (1) using electromagnetic leakage protection, the protection of electrical equipment enclosure can be connected to the protective earth (PE line) or the protection of the zero line (PFN line). In this case, may be checked for automatic switch, single girder  overhead gantry crane  but must be checked leakage protection (zero sequence transformer) dynamic stability and thermal stability.

     (2) the use of electronic leakage protection, the protection of electrical equipment and protective metal casing can also be connected to earth. In this case, in addition to checking the zero sequence transformer dynamic stability and thermal stability, should also check the single phase earth leakage protection when the auxiliary power supply voltage is within the allowable voltage range to leakage protection guarantee reliable operation.

     (3) Ground resistance should be able to ensure reliable operation of leakage protection.

     (4) When the distribution system leakage protection using hierarchical protection, in order to make the single girder gantry crane levels of protection selective action, at all levels of the breaking time should not be the same. At this point, if the protective earth at all levels can not be separated, then the deal breaking time readjusting to meet the requirements of the protection classification.

没有评论:

发表评论