Joe, Perhaps that's been your experience. In my experience, I've never not been able to resolve a "tingle problem".
The concern I have is the person who reads:
Originally Posted by
J Miller
If your machine gives you a buzz, even with good wiring, unplug the cord, rotate the plug and plug it back in. You just polarized the system, no more buzz.
Joe
and fails to evaluate the wiring and is hurt or killed as a result.
The fact is that people tend to plug in a lot of things that they really shouldn't. Encouraging someone to always have the wiring evaluated by someone qualified will never put them in harms way. Telling them that they can just flip the cord and all will be right with the world does potentially put them in harms way because fundamentally humans are lazy and will take the easy way nearly every time.
I have NEVER had one of my FWs
(or other machines) tingle or any of the ones I've worked on after wiring problems were evaluated and corrected. I have tried the plug both ways to test. If it was a design feature, all would do it. If they don't all do it, the ones that do should be corrected.
Modern household wiring is not configured much differently (we use different materials but the basic configuration hasn't changed) than old as far as the power being delivered to a two prong device. Mostly because AC power is still AC power - a sine wave that alternates between the positive and negative 120 times a second.
The old knot and tube wiring was ungrounded but otherwise used black (hot) and white (neutral) wires. The new wiring uses black, white, and a ground (sometimes bare, sometimes green) that we don't make use of in this case. Red is rarely used in the situation we're discussing. It's usually for a split plug, a three way switch or in the case of 220v wiring - for the hot in the second phase of the 220.
Positive and Negative
wires are a DC concept.
Positive is NOT the same as Hot
Negative is NOT the same as Neutral
The Hot wire of an AC system is responsible for both the positive and negative - because again as stated AC cycles 120 times a second - it's like a push / pull system this is what creates the sine wave I mentioned above.
There are some very good analogy explanations here:
http://www.controlbooth.com/threads/...-neutral.7724/