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. 金屬電纜橋架及其支架引入或引出的金屬電纜導管必須接地（PE）或接零（PEN）可靠，且必須符合下列規范:

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) 金屬電纜橋架及其支架全長，與接地（PE）或接零（PEN）干線相連接不小于2處，使整個橋架為一個電氣通路。

(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) 非鍍鋅電纜橋架間連接的兩端跨接銅芯接地線，接地線更小允許截面積不小于4mm2。

(2) The two ends connected between non galvanized cable trays shall be bridged with copper core grounding wire, and the minimum allowable cross-sectional area of grounding wire shall not be less than 4mm2.

(3) 鍍鋅電纜橋架間連接板的兩端可不跨接接地線，但連接板兩端不少于2個有防松螺帽或防松墊圈的連接固定螺栓。

(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. 盤、梯架端部之間連接電阻不應大于0.00033Ω并應用等電位聯結測試儀（導通儀）或微Ω表測試，測試應在連接點的兩側進行，對整個橋架全長的兩端連接電阻不應大于0.5Ω或由設計決定，否則應增加接地點，以滿足要求。接地孔應涂層，與涂層接觸的螺栓有一側的平墊應使用帶爪的專用接地墊圈。

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. 伸縮縫或軟連接處需采用編織銅線連接。沿橋架全長另敷設接地干線時，每段（包括非直線段）托盤、梯架應小有一點與接地干線可靠連接；在接地部位的連接處應裝置彈簧墊圈，以免松動。

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; spring washer shall be installed at the connection of the grounding part to avoid loosening.