This article discusses many common misunderstandings about the function of the neutral wire and its relation to power problems. The subjects of dedicated lines, phase reversal, isolation transformers, ...
When clients call you because operating problems on pieces of their 120V equipment cause them to suspect their facility's power supply, you have to decide where to start your investigation. Don't ...
There's something oddly comforting about the idea of fixing things yourself. You save money, learn something new, and get that little rush of satisfaction when it all works. That is, until it doesn't.