1. No grounding device It includes: the cart track does not have any metal connection to the earth or the neutral line. Although it is connected, it has been welded or the grounding wire has been disconnected; there is a connection, but the grounding body is unqualified. There are also some rails placed on the metal bearing rails, and the rails have metal pillars. Therefore, it is considered that the rails pass the rails and the pillars to form a qualified grounding. In fact, this is not the case. Because there is no welding between the rail and the bearing rail, it is pressed on the bearing rail by the pressing plate, and even the paper pad is placed in it, and the bearing beam and the pillar are painted with paint.
2. There is no metal jumper at the rail joint, only the fishplate is connected at the rail joint. Due to corrosion and other reasons, this is not the case. Some of the splints are not connected at the rail joint, and the rail width is 10mm, obviously, There is no leakage protection. In other cases, the grounding wire is fixed to the rail presser bolts, and some grounding wires are welded to the retaining iron at the end of the cart rail, and the retaining iron and the rail are not welded. Not conducive to safety.
3. The grounding wire section is smaller than the standard. Generally speaking, the grounding wire* is easy to use flat steel. However, many units use round steel. In the “Procedure”, only “flat steel with a section of not less than 150 mm should be used for the connection of the grounding wire”. The section of the round steel should not be specified. It may also be 150mm. That is, the diameter of the round steel should not be less than 13.8 mm, but most units use 10 mm round steel, and the individual units even use 4 mm round steel, and the cross section is obviously too small.