電銲機自動電擊防止裝置使用現況調查

The Survey and Recommendations of Electric Shock Preventing Devices for AC Arc Welding Machines

本文檢討國內電銲機自動電擊防止裝置的使用現況與問題，並針對國產品在品質上可改良之處及使用上應注意的地方提出建議。本文首先討論交流電銲機之安全問題，介紹自動電擊防止裝置之基本原理及參數的意義，並實地訪談數個曾使用自動電擊防止裝置的單位，及測量5台國產及2 台日製自動電擊防止裝置之性能。由訪談及實測結果顯示，大部分的國產自動電擊防止裝置參數設定值皆能符合國家標準，而造成使用者很不方便使用的主要原因包括廠商製造品質不佳、品管不良、防水性差、及內藏型周溫過高等因素使得故障率偏高，另外使用者使用習慣不佳，使得自動電擊防止裝置之視出電阻大於起動電阻，或選擇不適合之起動電阻值皆會造成點弧不易，造成勞工普遍不願意使用。自動電擊防止裝置的保護原理是正確的，應繼續鼓勵各界使用，但為使這種裝置方便且有效使用，本文針對製造商、使用單位、及勞工三方面提出建議以供各界參考。

This paper examines the present status and the problems of using the electric shock preventing devices for arc-welding machines in our country, and proposes the suggestions about where the product quality can be improved, and where the user should take notice. The safety problems of arcwelding machines are discussed at first, and then the basic principle and parameter definitions of electric shock preventing devices. The task force has discussed with welders in several working places for problem discovery, and measured 5 indigenous and 2 Japanese made market-available electric shock preventing devices for characteristic parameters. From the meetings, it is shown that most of the parameters of indigenous devices are compliant with the national standard. The main reason bothering the users is the high malfunction rate, which is due to poor product quality, quality control, and moisture bearing ability. Also, from the measurements and operating exepriences, it is observed that the arc is hard to be started when the secondary side resistance of electric shock preventing devices is higher than its starting resistance, or when there is no appropriate selection of starting resistance value. In general, high secondary side resistance of electric shock preventing devices is caused by bad installation and operation habit of the welding machine user. Difficult arc starting caused the users unwilling to use the electric shock preventing devices. Hence, the conclusion is that the protection principle of electric shock preventing devices is correct, and the promotion of using electric shock preventing devices should be continued. Finally, some suggestions for the manufacturers, user’s management departments, and labors are proposed in order to make the use of the electric shock preventing devices more easily and effectively.