不少電工在施工現(xiàn)場常有疑問：橋架不就是鐵的嗎？導電沒問題，還接什么地啊？明明里面都穿著帶金屬護套的電纜，還要橋架接地是不是重復了？橋架又不帶電，非得每段都搭根地線是不是多此一舉？別急，其實這是很多一線人員經(jīng)常誤解的地方，今天我們就徹底講清楚——電纜橋架，到底為啥必須接地？01行業(yè)誤區(qū)有以下三點誤區(qū)1：橋架不是電氣設備，不接地也不帶電，沒關系。

　　Many electricians often have questions on construction sites: Isn't the bridge frame made of iron There's no problem with conductivity, what else is there to connect to Is it repetitive to have cable trays grounded even though they are all wearing cables with metal sheaths inside Isn't it unnecessary to install a grounding wire on every section of the bridge since it's not electrified Don't worry, this is actually a common misconception among frontline personnel. Today, we will thoroughly explain why cable trays must be grounded There are three misconceptions in the industry: 1. Cable trays are not electrical equipment, and they are not grounded or charged. It's okay.

　　誤區(qū)2：橋架如果只是做電纜支撐結構，不當做保護導體，可以不接地。

　　Misconception 2: If the bridge is only used as a cable support structure and not as a protective conductor, it may not be grounded.

　　誤區(qū)3：電纜護套接地就夠了，橋架多此一舉。這些看似有“道理”的說法，其實在設計規(guī)范與現(xiàn)場安規(guī)里，統(tǒng)統(tǒng)站不住腳。02為什么橋架必須接地橋架是導電金屬結構，雖然本身不帶電，但在以下情況下很可能成為“危險載體”：電纜故障時的感應電壓：電纜護套損壞，故障電流可能短暫竄入橋架金屬體；意外接觸：誤操作或電纜破損導致相線與橋架接觸；感應耦合電壓：高壓電纜并排敷設時產(chǎn)生的感應電場，尤其在長距離布線中更明顯；靜電積聚：尤其在干燥環(huán)境中，橋架可積聚電荷，造成觸電感應。以上任意一點，都可能讓橋架成為一個“懸浮高電位體”，對人員構成危險。03規(guī)范依據(jù)與強制性要求在《建筑電氣工程施工質量驗收規(guī)范GB50303-2015》《電網(wǎng)安規(guī)圖冊》《民用建筑電氣設計規(guī)范JGJ16-2008》等明確指出：金屬橋架必須接地，視為電氣設備外露可導電部分。不得以橋架替代PE線，橋架接地不可用作主接地干線。每段橋架之間應可靠電氣連接，跨接線需壓接或焊接處理，防止松動失效。跨接線的小截面積應符合規(guī)范要求，通常銅芯跨接線不應小于 4mm，以確保故障電流的導流通路可靠。也就是說，不管你現(xiàn)場看起來“帶不帶電”，“危險不危險”，橋架接地不是“建議”，是強制性條文！04橋架接地常見問題盤點在工程檢查與運行中，以下問題極為常見：

　　Misconception 3: Grounding the cable sheath is enough, it's unnecessary for the cable tray. These seemingly reasonable statements are actually untenable in design standards and on-site safety regulations. Why must the cable tray be grounded The cable tray is a conductive metal structure that, although not electrically charged, may become a "dangerous carrier" in the following situations: induced voltage in the event of cable failure: cable sheath damage, fault current may briefly enter the metal body of the cable tray; Accidental contact: accidental operation or cable damage leading to contact between the phase line and the bridge frame; Inductive coupling voltage: The induced electric field generated when high-voltage cables are laid side by side, especially in long-distance wiring; Static electricity accumulation: Especially in dry environments, cable trays can accumulate charges, causing electric shock induction. Any of the above points may turn the bridge into a "suspended high potential body", posing a danger to personnel. The basis and mandatory requirements of the 03 standard are clearly stated in the "Code for Acceptance of Construction Quality of Building Electrical Engineering GB50303-2015", "State Grid Safety Regulations Atlas", "Code for Electrical Design of Civil Buildings JGJ16-2008", etc.: Metal cable trays must be grounded and considered as exposed conductive parts of electrical equipment. Cable trays shall not be used as a substitute for PE wires, and cable tray grounding shall not be used as the main grounding line. Each section of the bridge should be reliably electrically connected, and jumper wires should be crimped or welded to prevent loosening and failure. The minimum cross-sectional area of the jumper wire should meet the requirements of the specifications. Generally, the copper core jumper wire should not be less than 4mm to ensure the reliability of the fault current diversion path. That is to say, regardless of whether you appear to be "electrified" or "dangerous" on site, bridge grounding is not a "suggestion", but a mandatory provision! In the process of engineering inspection and operation, the following issues are extremely common:

　　問題風險原因橋架與橋架連接處無跨接線電氣連續(xù)性中斷，故障電流無法導走施工偷工減料或未驗收接地線僅在起始端接一次長距離橋架末端存在懸浮電位沒有分段接地意識使用鋁橋架未做防腐電纜鼻子連接接觸電阻過大，接地失效沒有使用專用接地配件把橋架當作PE線用不符合規(guī)范，存在故障電流過載風險慣性做法，圖省事特別提示：在鋁制橋架或不同材質橋架連接時，為防止電化學腐蝕導致接觸電阻增大，應使用過渡連接片或采用銅鋁過渡端子進行連接，嚴禁將銅導體直接與鋁橋架表面壓接。

　　The reason for the risk of the problem is that there is no jumper wire at the connection between the bridge and the bridge, and the electrical continuity is interrupted. The fault current cannot be conducted. Construction has been cut corners or the grounding wire has not been accepted. Only one long-distance bridge is connected at the starting end. There is a floating potential at the end of the bridge, and there is no awareness of segmented grounding. The aluminum bridge is not used for anti-corrosion cable nose connection. The contact resistance is too high, and the grounding failure does not use special grounding accessories. The bridge is used as a PE line, which does not comply with the specifications and has the risk of fault current overload inertia. The picture is convenient. Special reminder: When connecting aluminum bridge or bridge of different materials, in order to prevent electrochemical corrosion and increase the contact resistance, transition connection pieces or copper aluminum transition terminals should be used for connection. It is strictly prohibited to directly press the copper.

　　一句話：橋架接地，不是你愿不愿意，是必須做、要做對、還得做全的硬性要求。

　　One sentence: Bridge grounding is not something you are willing or unwilling to do, but a mandatory requirement that must be done, done correctly, and fully implemented.