The grounding of cable tray shall meet the following requirements when the design allows the use of tray system to form grounding trunk circuit:

1.金属电缆桥架及其支架引入或引出的金属电缆导管必须接地（PE）或接零（PEN）可靠，且必须符合下列规范:

1. The metal cable conduit leading in or out of the metal cable tray and its support must be reliably grounded (PE) or neutral (pen), and must comply with the following specifications:

(1)金属电缆桥架及其支架全长，与接地（PE）或接零（PEN）干线相连接不小于2处，使整个桥架为一个电气通路。

(1) The total length of the metal cable tray and its support shall be connected with the grounding (PE) or neutral (pen) main line at least two places, so that the whole tray is an electrical path.

(2)非镀锌电缆桥架间连接的两端跨接铜芯接地线，接地线小允许截面积不小于4mm2。

(2) The two ends of non galvanized cable tray are connected with copper core grounding wire, and the allowable cross-sectional area of grounding wire is not less than 4mm2.

(3)镀锌电缆桥架间连接板的两端可不跨接接地线，但连接板两端不少于2个有防松螺帽或防松垫圈的连接固定螺栓。

(3) The two ends of the connecting plate between the galvanized cable trays may not cross the grounding wire, but the two ends of the connecting plate shall not be less than 2 connecting fixing bolts with locking nuts or locking washers.

2.盘、梯架端部之间连接电阻不应大于0.00033Ω并应用等电位联结测试仪（导通仪）或微Ω表测试，测试应在连接点的两侧进行，对整个桥架全长的两端连接电阻不应大于0.5Ω或由设计决定，否则应增加接地点，以满足要求。接地孔应涂层，与涂层接触的螺栓有一侧的平垫应使用带爪的专用接地垫圈。

2. The connection resistance between panel and ladder end shall not be greater than 0.00033 Ω, and shall be tested by equipotential bonding tester (conductometer) or micro Ω meter. The test shall be conducted on both sides of the connection point, and the connection resistance at both ends of the whole bridge length shall not be greater than 0.5 Ω or determined by the design, otherwise, the grounding point shall be added to meet the requirements. The coating shall be removed from the grounding hole, and the special grounding washer with claw shall be used for the flat pad on one side of the bolt in contact with the coating.

3.伸缩缝或软连接处需采用编织铜线连接。沿桥架全长另敷设接地干线时，每段（包括非直线段）托盘、梯架应小有一点与接地干线可靠连接；在接地部位的连接处应装置弹簧垫圈，以免松动。

3. The expansion joint or flexible joint shall be connected with braided copper wire. When another grounding main line is laid along the full length of the bridge, the tray and ladder of each section (including non-linear section) shall be reliably connected with the grounding main line at a small point; The spring washer should be installed at the connection of the grounding part to avoid loosening.