Terminals often occur in the course of a wide variety of issues. If the Terminal black, one of these possibilities is not necessarily burnt black, or Black oxide. What about is how to verify burned black? Our method is cleaning his fingers, if it is erased, just like ash, which is to be formed by oxidation of black material, sandpaper or files to wear off. Czech electrical terminal experts remind you, one thing to note here is: when charged can be sure not to rub with your fingers!

Then another possibility is burnt black, in addition to fire and Gong qigong masters, there is only one possible, is the wiring Terminal to overheat at high temperature. Cause of high temperature, there are two possibilities: loose Terminal contact resistance greatly, thus overheating; Terminal is not loose, but the loop for some unknown reasons the current heating, such as the supply voltage is too high, or load short circuit.