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Author Topic: Right or Wrong? New building has receptacles with Hot and Neutral reversed.  (Read 2545 times)

Mike Sokol

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #10 on: September 11, 2017, 08:10:06 am »

I was in disbelief. Therefore , I did verify the Extech CT80 tester at home after the show and 30 seconds ago on my current show. It works as it should. Also, on the show that day I use 12ga SJ cables with an outlet tester that's integrated into the Edison connector. They usually glow green when all is good and red when something is wrong. On this day the green and red LED's were on simultaneously on all 4 of them regardless of where I plugged them in. I have never seen that.

I would also get a meter on it just to triple check. Here's what I send to my RV groups on how to measure a standard 120-volt outlet.

John Roberts {JR}

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #11 on: September 11, 2017, 10:44:59 am »

I would also get a meter on it just to triple check. Here's what I send to my RV groups on how to measure a standard 120-volt outlet.


While I have abandoned my outlet tester I explain why simple AC voltage measurements can be tricked. The rare but hazardous RPBG will measure exactly the same as a properly wired outlet using a simple AC meter.   http://www.johnhroberts.com/OD1.htm

The less hazardous, but still incorrect line-neutral reverse can be effectively metered with a simple AC meter since ground to neutral will not measure 0V.

I have shared this before a crude but simple way to identify if outlet pins are energized is to use a cheap Neon lamp probe.

Holding one lead of the neon lamp probe in your bare hand, touch the other lead to the outlet pins. Any hot pins will cause the neon lamp to glow dimly. Current "should" be limited to well below dangerous levels, but don't do this while standing in your bathtub full of water.

I do a similar trick with a VOM but am reluctant to share details since you can get shocked using the wrong mode.

JR

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Nathan Riddle

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #12 on: September 11, 2017, 10:52:41 am »

I do a similar trick with a VOM but am reluctant to share details since you can get shocked using the wrong mode.

JR

Or cheap VOM with low internal resistance ;)
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Ed Hall

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #13 on: September 11, 2017, 02:26:51 pm »


I do a similar trick with a VOM but am reluctant to share details since you can get shocked using the wrong mode.

JR

What about a NCVT? Wouldn't that give the same results, and be the correct tool for the job?
« Last Edit: September 11, 2017, 08:38:58 pm by Ed Hall »
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Mike Sokol

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #14 on: September 11, 2017, 07:19:44 pm »

What about a NCVT? Wouldn't that give the same results, and be the correct tool for the job?

Here's how to use a NCVT to test for swapped Hot and Neutral wiring as well as a RPBG. https://www.youtube.com/watch?v=XfAPkJVYUpY

John Roberts {JR}

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #15 on: September 11, 2017, 07:39:06 pm »

What about a NCVT? Wouldn't that give the same results, and be the correct tool for the job?
The cheap NCVT I own will sound in the same time zone as an outlet. Perhaps a more expensive one will have lower sensitivity.

But yes if a grounded metal chassis, triggers an NCVT alarm approach with caution. 

JR
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Ed Hall

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #16 on: September 11, 2017, 08:53:40 pm »

The cheap NCVT I own will sound in the same time zone as an outlet. Perhaps a more expensive one will have lower sensitivity.

But yes if a grounded metal chassis, triggers an NCVT alarm approach with caution. 

JR

This is the one I have Fluke 1AC II A1 and I have to insert the tip into the receptacle slot to sense the voltage. I've only had it alert once while approaching the receptacle and the Line had broken insulation and was energizing the metal box behind the wall board.
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Mike Sokol

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #17 on: September 11, 2017, 09:08:04 pm »

This is the one I have Fluke 1AC II A1 and I have to insert the tip into the receptacle slot to sense the voltage. I've only had it alert once while approaching the receptacle and the Line had broken insulation and was energizing the metal box behind the wall board.

That's also the one I use in all my videos and seminars, and it works perfectly all the time. They only cost around $25 or so, and like any Fluke it should last forever.

John Roberts {JR}

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #18 on: September 12, 2017, 10:36:00 am »

That's also the one I use in all my videos and seminars, and it works perfectly all the time. They only cost around $25 or so, and like any Fluke it should last forever.
Mine cost a small fraction of $25 and will detect live wiring behind walls... :o  Perhaps useful would be a sensitivity switch or adjustment.

Professionals should probably buy something other than the cheapest NCVT.   8)

JR

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Jeff Bankston

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Re: Right or Wrong? New building has receptacles with Hot and Neutral reversed.
« Reply #19 on: September 19, 2017, 03:48:44 am »

I use to see a lot that when I worked as a commercial electrician. There are a lot of guys working as electricians that are not qualified to even put on a receptacle cover plate. I was sent to help a foreman on the tail end of a job. I saw a few receptacles that were crooked and decided to check them with my tester after I straightened them. My plug tester lit up weird and iirc my meter read about 200 volts on the hot and neutral. I went to the new breaker panel and the neutral was pumping out about 118 volts. I turned off the transformer disconnect and pulled the cover and the XO was not grounded. There was a ground rod next to the xformer and the ground wire was lugged to the case but there was no jumper to the XO lug. The foreman told me the owner sent out his best electrician to wire it up and that he did not need to check it. Well his best electrician didnt have a clue and the foreman should have never been made a foreman cause he didnt know how to wire a xformer. I saw a lot of crap like this. Also the electrical certification is BS. All a guy has to do is take the class and learn the answers and pass the test and they get their journeyman card and they dont know crap. Every guy that I interviewed that had a card could name most of the basic electrical tools on my 100 question "fill in the blank" test. I dont do multiple choice where a complete idiot could win the lottery.
« Last Edit: September 19, 2017, 03:50:55 am by Jeff Bankston »
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