My friend had wiring done on an addition a couple years ago. Every thing worked fine TVs, VCR, vacuum, whatever was plugged in until recently. One day her "shop vac" was plugged in and working then suddenly quit. The breaker didn't blow, but eventually all the plugs on the circuit have quit working. An electrician friend of hers says the wiring is reverse polarity? Does this make sense? Can something caause the polarity to switch? I'm thinking maybe the breaker went bad? The "shop vac" still works. Sorry to say I don't have alot of info at this time, but it just sounded wierd to me? Thanks, MHS MOM
You don't say your country, so I'll give you a UK slant.
Sounds like whoever did the wiring fitted extremely cheap and nasty mains sockets, rather than branded ones, on the new ring main. One by one these have stopped working with use. She perhaps was in the habit of not switching off the shop vac, or portable heater, electric iron, whatever, before plugging it in/unplugging it - and the "splash" (spark) from that has wrecked these tatty sockets.
Her "electrician friend" wasn't the one who did the installation, per chance?
The breaker may indeed be bad - if the installer like tatty sockets, he may easily love tatty breakers.
That is, unless she is like me, living well off the beaten track with a dc ring main as well as an ac one - but that is pretty rare in the uk. I do have to worry about polarity but there is no way it could reverse all by itself.
"Polarity" is normally considered to be whether one supply terminal is positive or negative to the other - which for a normal electrical supply does indeed reverse. Often. Like many times every second. It may be less often on whatever planet the friend lives. But I suspect that he may be the installer and saying any old crap to divert attention from other any old crap - the stuff he installed.
As a follow-up to the above, whatever problem you have, the issue is not "reverse-polarity" unless you are living in a country where the electric company is supplying you with DC instead of AC.
Maybe, there is some isolated island somewhere, where this may be true, I don't really know... But you can pretty much safely assume that you are dealing with AC (Alternating Current) which, strictly speaking, doesn't have a polarity... although in the US and some other countries, you can buy "polarized" plugs and outlets.
I am not so clear on your problems. But i tried to give some explaination on it. Your have said, your wiring have done as your mantion until you got the problems. it means that the wiring system is normal may be your shop vec faulty somewhere.
if you connected from sources with reverse points soppose the shop vac still run. But, when we narrow down the connection, it become wrong connections with no safety. What you need to do is; 1. Check the wiring connection on the plug top (13A) may be consists with fuses. 2. Check the capacitor running motor. It could be fault if the testing reading does't pointed damping pointer (analogue)or stable reading (digital)- normally capacitor.
check the sources wheather the supply available on that line.
If you find does't work, leave it and get new one.
To test capacitor, you may use digital multimeter or analogue multimeter. Do not test capacitor when the shop vac running. very dengerous-- need high current when starting.
In the US I think reverse polarity would usually refer to hot and neutral reversal. If they were all reversed the vac would still work. Could be an open neutral which would give a strange indication on outlet testers. Not impressed by the electrician - I don't think s/he found the cause of dead outlet(s).
Reverse polarity would not cause the problem, cannot cause the problem, and did not cause the problem. All the stuff you mention will work fine, whether the polarity is normal or reversed. It is quite possible that the polarity IS reversed. The term "Reversed polarity" as applied to 120 vac receptacles, means that the neutral wire and the hot wire are reversed. The ONLY way that can happen is by a wiring error by the installer or by someone who worked on the circuit later. Proper wiring requires that the white wire be connected to the neutral bus in the service panel, and to the silver colored screws at the receptacle, and that the black wire be connected to the circuit breaker at the service panel, and to the gold colored screws at the receptacles.
Here's the likely cause of the problem: the original installer wired the receptacles by "backstabbing" - stuffing the wire into a hole in the back of the receptacle. That is a legitimate method, but time has shown that circuits wired with that method are far more prone to the kind of failure you describe than circuits where the receptacles are wired by twisting the wire into a loop around a screw, and then tightening the screw.
If only part of the circuit is failing, the problem is located at either the last receptacle on the circuit that works, or the first one that fails, like this: ok ok ok F F F panel===[R]===[R]===[R]===[R]===[R]===[R] The defect is here >| | between the lines
If the whole circuit is failing, the defect is from the panel to the first receptacle, inclusive.
If there are multiple defects, they can be anywhere.
It would help, of course, to know the OP's country! None of that you ahve written above would apply in the uk. The OP, IIRC, also mentioned that the sockets were failing one by one..until several/all stopped working.
The poster said it's the US in a post on 8/23 at 10:01. Also said, in the original: > The breaker didn't blow, but eventually all the plugs
which leads one to think it was a one by one failure. And that may be true, but otoh I've encountered that description a number of times, where the description is wrong. What happens in those cases is that they encounter a failure in one receptacle (#1), and plug in elsewhere to receptacle #2. A day or a week or whatever passes, and they plug into a 3rd receptacle (#3), and it's dead, too. So they plug in elswhere (receptacle #4). It happens again, with the same scenario (receptacle #5 bad, and receptacle #6 good, and they describe the failure to the electrician as one by one failures, when actually all three receptacles (#'s 1, 3, 5) died at the same time, but the discovery sequence made it seem like it was one failure after another. 100% (minus a very small fraction) of the people do NOT know which receptacles "belong" to a circuit. If the pattern was known at the time of the first failure, and if there was a circuit map showing the odd #'s on one circuit and the even #'s on another, it's a lot more obvious.
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