Doubt regarding checking AC with tester

[savvej]

I have a extension board and it has a 3 pin socket and a switch associated with it.

Its connections are as shown in diagram attached :


Now when I switch "on" the switch,the led/lamp (am not sure) inside glows inside it.
Now when I take the tester and put it in the L hole--it lights up as expected.
But when I put it in the neutral plug ,the tester does'nt light up.
Now according to the diagram which I have shown,I should be getting voltage on neutral too because it is connected via led and resistor to the neutral.And thus tester should have lit ...why is it not happening so?

Note that this case is different from just having a plug and a switch with no lamp associated with it..

PS. added photo of tester(just in case if you call it differently)

 

[debe]

Your tester is working fine, if it lit up on the Neutral I would be worried.

 

[savvej]

There is some problem...Forget about this circuit.
Just consider a lamp connected across a ac supply as follows:

Initially ~ ----/\/\/\/\---- _/ __ ~
After switch is closed ~-----/\/\/\/\---__.__ ~

Now whether I touch left end or right end ,both are live .and tester should show high at both ends ?should'nt it?

 

[Nigel Goodwin]

There is some problem...Forget about this circuit.
Just consider a lamp connected across a ac supply as follows:

Initially ~ ----/\/\/\/\---- _/ __ ~
After switch is closed ~-----/\/\/\/\---__.__ ~

Now whether I touch left end or right end ,both are live .and tester should show high at both ends ?should'nt it?

It depends entirely on which connection is live and which is neutral.

If live goes to the switch (as it should), then it will read on both sides of the switch (and one side of the bulb) when it's turned ON, and only on one side of the switch when it's turned OFF.

 

[savvej]

okay.consider right to live and left to neutral(wrt the figure shown by me above).
But ac is bidirectional(as in changing its direction continuously(once switch is closed)- from left to right and right to left),so whether I touch left or right I should have potential wrt earth at both these points.So tester should work at both points ,should'nt it?

I think that in the diagram which I have put at the start is faulty.
Maybe the other end of the lamp(in the switch) is connected to ground and not neutral.

 

[Nigel Goodwin]

okay.consider right to live and left to neutral(wrt the figure shown by me above).
But ac is bidirectional(as in changing its direction continuously(once switch is closed)- from left to right and right to left),so whether I touch left or right I should have potential wrt earth at both these points.So tester should work at both points ,should'nt it?

No, only the live will affect that crude tester - neutral is connected to earth (which is what makes the tester work).

 

[MrAl]

Hello,

From what i know about those kinds of testers (i use two wire testers only) they do not show an active line unless the breaker is turned 'on' (even when the tester is held outside of the Romex cable but close to the outside jacket), and the breaker usually only breaks the 'hot' wire, not the 'neutral' wire. That means they can not pick up a signal from the neutral wire, only from the hot wire if it is turned on at the breaker box.
Of course this means you would not get a reading on the neutral line even if the breaker was turned 'on'.

Also, just because you have something connected between the hot and neutral that doesnt make the neutral 'hot', it's still neutral, so you still wont get a reading even with a 100 watt bulb connected in the circuit.

You might want to mention what exactly you want to test for...what you are trying to find out here.

 

[savvej]

I got it.Actually I had some misconceptions which got cleared from :
https://scottiestech.info/2009/05/1...neutral-and-earth-ground-in-ac-installations/

Thanks to all for helping.

 

[kiriakos-gr]

Speaking about AC testers, check this out ... with phase direction indicator.

https://www.eevblog.com/forum/index.php?topic=4323.0