Image: Burnt terminals

Description: Burnt screw terminal. As you can see, workers with certificate also can make mistakes. What was the mistake? -Previous qualified specialist had connected old aluminium cable to new copper cable inside screw terminals. After washing machine worked for six months with this connection, a burning smell became evident inside the apartment. When the apartment owner called me, I hadn't seen such a method of wiring! What was the reason? -There was fresh spackling paste and paint in the stairs, but the electrician didn't want to break into the freshly filled walls to put a new cable. He left old the aluminium cable between the distribution board and junction box inside the apartment.
Title: Burnt terminals
Credit: Own work
Author: Dmitry G
Permission: I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No