"JC" wrote in message news:pMydnRsHZr9cMfXXnZ2dnUVZ snipped-for-privacy@giganews.com
The vast majority of the time there ARE no blueprints on existing homes. You're lucky to even find a written description of wiring sometimes. A multi-tester will not tell you where a buried, inaccessible junction box is located. In fact, there is almost no way short of expensive equipment to even locate it to within a few inches of its actual location. The symptom would not be 240Vac; in a residential NA setting it would be a loss of 120Vac 99.9% of the time. If it goes to 240, there is much more wrong than an inaccessible junction box, which itself gives no indication that it even exists, let alone where it is. It's not covering a junction box with sheetrock that's a problem: It's the inaccessibility of the junction box regardless of coverings that is the problem. IF for instance the box were accessible from the other side of the wall, ceiling, etc., then that's fine. A "hot" junction box is not going to identify itself and in the hands of a poor tech may result in an inability to even realize one exists; while the house burns down that night. But if it's exposed it's easily traced and found to be hot, by any competent tech with a current license. Read the code: It gives the reasons behind it. You're welcome to your opinions but that doesn't mean others need to follow you or should depend on you. Since you participate on this group I have to assume you're involved with electrical work and thus are not credible or reliable. Your attitude makes your comments questionable.