Newsletter 高速鐵路簡訊 . 交通部高速鐵路工程局
機場捷運月臺門系統結構絕緣改善措施探討 Insulation Improvement Measures for TIAA MRT Platform Screen Door Systems
月臺門絕緣改善施工情形

改善月臺門結構絕緣之目的,在增加月臺門結構與車站建築間之絕緣電阻值,進而促使月臺門與電聯車具有相同之電位,以免月臺門與電聯車之電壓差過大,造成旅客或站務人員感電,且月臺門組若有接地絕緣失效情形,鋼軌上之負電流恐有燒壞月臺門控制單元電路板之虞。因機場捷運之月臺門組與鋼軌係採浮動式接地方式,依規範其與車站建築間之絕緣電阻應為0.3MΩ/250Vdc以上。
經現場查驗及測試結果,部分月臺門結構絕緣有不足情形,本局捷運工程處已要求承商進行絕緣改善,相關缺失原因包括月臺門支柱底座下方之絕緣墊塊因受力不均破損而影響絕緣及支柱底座下方增設底板造成絕緣間距過小等設計因素;以及安裝施工時因支柱固定螺栓過長而碰觸門組外框、金屬墊圈裝設不當而碰觸底座、切割螺栓後未立即清除鐵屑及底座凹槽面未修飾並抹平而影響絕緣等施工因素。此外月臺門廠商應透過界面協調會,事先與土建標釐清界面需求,例如圍籬若沙袋破損,其砂漿流入月臺門底座凹槽,亦將破壞絕緣。
部分車站上述缺失改善後,絕緣值雖仍受天候變化(起霧、下雨)影響,惟因門組面板採陽極處理,且月臺門側2.5米範圍內的月臺鋪有絕緣膜,將不致影響人員安全。

The purpose of improving the insulation of platform screen doors (PSD) is to increase the insulation resistance between PSDs and station building structure which will indirectly causes PSD and EMU having same potential. In this case where voltage difference between PSDs and EMUs are avoided, electric shocks that may be experienced by passengers and station staffs can be prevented. If PSDs unfortunately encounter grounding failure, the negative return current in the rail may burn the control unit circuit board of the PSD. Since the PSD s and rail tracks adopted floating grounding, the insulation resistance between PSD and station structure is regulated to exceed 0.3MΩ/250Vdc.
Upon on-site inspection and test results, insufficient insulation areas were discovered and the MRT Engineering Office of BOHSR demanded the contractor to show correction and improvement. Reasons of insufficient insulation include design factors such as damages of the insulation gasket caused by uneven pressure and the additional base plate causing the insulation gap being too narrow; Construction factors such as extended stationary bolts of piers causing direct contact with the door frame, improper installation of metal washers resulting in direct contact with the base, iron scraps of segmented bolts were not properly removed, and uneven surfaces were not corrected and smoothed. In addition, the PSD contractor should hold CIP meetings with civil engineering tender contractors in advance for verification to prevent disturbing issues such as torn up sandbags causing Cement Asphalt Mortar to fill up the platform door base grooves and disrupts insulation.
After correcting the above deficiencies, insulation still fluctuation on account of weather change (fog, rain, etc.) at some stations. Fortunately, the door panels are anodized and an insulation film is applied under the platform surface within 2.5m range nearby PSD so that there would be no casualties if this happens.

  • 分享: