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I've got a "Meterk GFCI Electric Socket Tester" that can detect "live neutral reverse" and "hot/neu reverse" cases.

Meterk E2752

What could be the difference between these cases? Isn't "live" a synonym of "hot"?

Thanks.

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  • \$\begingroup\$ Switched neutral rather than hot? \$\endgroup\$ Dec 20 '18 at 22:32
  • \$\begingroup\$ live is a synonym of hot \$\endgroup\$
    – Chu
    Dec 20 '18 at 23:11
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    \$\begingroup\$ Steph_P92 - Hi, For readers to see the specific tester you are referring to, it would help if you edit your question and add a link to your tester's product page on the manufacturer's website. I found this E2752 GFCI tester branded "Meterk" and wondered if this was your one (or at least similar)? It has the same two display options which you mention. Thanks. \$\endgroup\$
    – SamGibson
    Dec 21 '18 at 0:44
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You can reverse engineer the meanings of the lights -- red means "hot is grounded (instead of live)", first green means "current flows between hot and neutral in either direction", second green means "current flows between hot and ground in either direction".

Most similar testers don't bother provide a key for the unlikely situation where all three lights are lit. It would happen when both neutral and ground are hot, and hot is grounded. "LIVE NEUTRAL REVERSE" doesn't seem like a great description of this but I'm not sure what would be. It would never happen unless the whole house is EXTREMELY badly miswired, or something has gone implausibly wrong with the wiring of the outlet.

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  • \$\begingroup\$ If people did not make those mistakes, then there would be no reason to test for them... \$\endgroup\$
    – Solar Mike
    Dec 21 '18 at 10:14
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    \$\begingroup\$ Can you clarify what "current flows into" means when the current is ac? Are you really trying to say something about the relative voltage of the hot line with respect to ground or neutral? \$\endgroup\$ Dec 21 '18 at 14:07
  • \$\begingroup\$ Hmmm @ElliotAlderson you're right. Except relative voltage doesn't help either -- it's alternating, same as the current. I have made my answer more accurate but also slightly more vague. I'm now curious to see a schematic of one of these things. \$\endgroup\$ Dec 21 '18 at 23:39
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"Live" or "Hot" were used for a long time to refer to line voltage conductors, ex. "That's yer hot wire and that's yer neutral" in colloquial terms. This is inadequately specific so it's being phased out. The new convention is that "Live" and "hot" refer to any conductor that is energised to a voltage significantly different from ground, including things that are not wires, so now we might say "Back off! The frame is hot!" or "Yep! Circuit 21 is live at the panel!" it is no longer proper to say "Pull the hot wire." to refer to a wire that is not currently energised. A conductor at line voltage that is turned on can be referred to as live or hot, but so could a conductor that is energised to a non-standard voltage. A bit of a squares and rectangles problem.

"Line" means a conductor that should be at system voltage when energised, which could be 120, 240, 347 or whatever volts to ground.

"Neutral" is still used much more widely than "Hot", but is nonetheless being phased out in favor of "identified conductor" because of the fact that "neutral" might imply "safe" to the uninformed. The more current is travelling on a neutral between the measurement point and source, and the more resistance and impedance that current travels through, the more voltage there will be from ground at the measurement point and the more danger. Also note that not all identified conductors are white. They chose the phrasing "identified conductor" to point out that it is the conductor that is marked differently, so if you have a flat black 2 wire extension cord wire, feel the outside of it and note that one of the wires has a ridge in the plastic along the length. Sometimes a black wire with an axial line is also used. This should be used as the identified conductor when relevant. Note that the definition of an identified conductor or neutral is the conductor in a system that carries the unbalanced current. It is connected to ground at the source, but should be treated as live unless every circuit it feeds is de-energised.

"Ground" has had it's definition improved as well. Previously anything that was connected to the earth was referred to as ground. The new convention is that only something that is directly connected to the earth is "ground" or "grounded", so this means that the grounding electrode/rod/plate/grid, and the green or bare copper wire attached to it, up to the first point of termination is "ground", and everything past that point is "bond". Grounding connects things to the earth, bonding branches out to continue the connection. Bonding wires are also green or bare copper.

At any rate my tester is a Sperry but likely has the same indications as yours. They are as follows:

Lights are Red, Yellow, Yellow from left to right

X=On, O=Off

OXO - Open ground - Ground is disconnected between plug and panel

OOX - Open neutral - Neutral is disconnected between plug and panel

OOO - Open hot - Line wire is disconnected between plug and panel. No power to light the indicators so there may be another problem present.

XOX - Hot/ground reversed - Line and ground wires are terminated on eachother's screws

XXO - Hot/Neutral reversed - Line and neutral connections are switched with eachother. Because ground is not involved the problem may be in another box. Insidious because devices will still work and average people will not know anything is wrong. Plugging in the wrong device may produce a short to ground.

OXX - Correct

There should be these six outputs and no others. Does your device have a seventh output or is it perhaps mislabeled? You can verify your plug tester's function by wiring a receptacle to an extension cord to a receptacle in each way.

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    \$\begingroup\$ Hi, "Does your device have a seventh output" Yes (or at least I found a GFCI tester of the same make as the OP, which has that 7th display output option). See the link in my comment under the question. As you list, many (most?) such testers have those 6 display options. However, following this question, I searched and found just a couple of testers which also have the 7th display option. \$\endgroup\$
    – SamGibson
    Dec 21 '18 at 1:45
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    \$\begingroup\$ @SamGibson Thanks. I hadn't seen a picture of his device yet and it didn't occur to me that it would show the 7th option and still be so horribly labelled. "Live neutral and ground" would be adequate, "all wrong" would even be adequate. Glenn covered that in his answer but I felt like writing so I added some information that will be helpful at OP's skill level. \$\endgroup\$
    – K H
    Dec 21 '18 at 2:15
  • \$\begingroup\$ How about marking it "Everything is ruined forever" or "Run for the hills"? \$\endgroup\$ Dec 21 '18 at 8:36
  • \$\begingroup\$ Hi, thanks for all your answer. I added a link in my first post. I've 7 outputs in my tester. \$\endgroup\$
    – Steph_P92
    Dec 21 '18 at 10:56
  • \$\begingroup\$ Hi! As suggested, I've tested different wiring with extension cord. I found by chance the case when "live neutral reverse" is displayed ! :) It is when: - Live wire is connected to Neutral terminal of the socket - nothing is connected to Live terminal of the socket - ground wire is connected to ground terminal of the socket :o) \$\endgroup\$
    – Steph_P92
    Dec 21 '18 at 21:18
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As suggested, I've tested different wiring with extension cord.

I found by chance one case when "live neutral reverse" is displayed ! :) It is when: - Live wire is connected to Neutral terminal of the socket - nothing is connected to Live terminal of the socket - ground wire is connected to ground terminal of the socket :o) In fact, it's "open neutral" on a socket where Live wire is connected on Neutral terminal. (perhaps there are other cases giving this same result)

"Hot/neu(tral) reverse" is when - Live wire is connected to Neutral terminal of the socket - Neutral wire is connected to Live terminal of the socket - ground wire is connected to ground terminal of the socket

Hope it can help other users !

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