Hi everyone, this is [Chengyang Electrical Circuit]] YouTube only channel ~ I am a common electrician in Qingdao, Shandong Province, working for 18 years Maintenance and installation of factories, equipment, homes, various circuits Share electricity knowledge, maintenance process, various circuit maintenance examples video If you like my video, you can subscribe to it ~ https://www.youtube.com/channel/UCcxNeq5YgvdQkcKqDPvRDMg?sub_confirmation=1