How to identify Phase-Neutral in 2 pin power cord?

[Thad E Ginathom]

Folks, READ the question. He wants to know how to identify which pin in a two pin POWER CORD is meant for phase.

)my added bold.

Neither is.

if it mattered the manufacturer would have fitted a three-pin plug.

 

[prankey]

Normally the right pin on the Appliances is Phase. I don't think any Audio device will have any other arrangement. So just trace the pins and your can tag them accordingly.

 

[Amitkg]

Normally the right pin on the Appliances is Phase. I don't think any Audio device will have any other arrangement. So just trace the pins and your can tag them accordingly.

But the question is when you have 2 pin plug without any '+' or '-' marking and when left profile and right profile of that 2pin plug look exactly same, how will you identify the pin meant for phase(+) ?

Sent from my MI MAX using Tapatalk

 

[sunder]

But the question is when you have 2 pin plug without any '+' or '-' marking and when left profile and right profile of that 2pin plug look exactly same, how will you identify the pin meant for phase(+) ?

Sent from my MI MAX using Tapatalk

Rarely some manufacturers provide the 2 pin power cable with 'white' line printed along the 'phase' side. If it's not an important thing then why they provide such type of wire to indicate the phase side? Thanks.

 

[sunder]

By my mistake, posted my reply as twice and deleted the repeated post. Thanks.

 

[hdmaniac]

If the correct contact of phase - neutral pins are critical to the system's functionality or quality, I am sure the manufacturer would have clearly indicated so or in simplest terms, given a three pin plug with a dummy ground pin even if the equipment does not need ground. The two pin with no clear distinction just means its designed to work as expected in either ways IMHO.

Cheers!

 

[pushkarDighe]

Hi All,
Bit off track but if you are getting that slight tingling sensation when you touch metal part of your AV then it can mean that there is some "more or leak" voltage in the -ve or neutral line.
I have this issue crop up in my house. The wiring is concealed so tracing where exactly the fault lies is not possible as of now. Called electrician but since his tester could not sense the voltage it was "NO problem" for him.
Since I was not convinced and feared my expensive equipment this is what I did.
First I had all the AV equipment connected with each other using metal wires (no optical only wires), Even for network used UTP cable instead of Wifi. Then on one of the equipment (my BD player in this case) I loosened one casing screw, cleaned (used a very fine sand paper) the paint from the area around the screw and connected a standard wire to the screw. The other end of the wire was fixed to the ground pin of a 3 plug and that was plugged to my Belkin spike guard.
The tingling was "gone". Did not notice any change to picture or audio but felt assured that now my equipment is safe.
Maybe the present day electronic equipment are well designed and built that they do not need grounding and 2 pin power plug is sufficient. Still I feel they should have 3 pin at least for heavy equipments like amps.

Thanks
pushkarDighe

 

[philipreji]

Last week I had got a tingling sensation from a USB flash drive (with metallic case) when I inserted it to the USB port on my computer at home. When I checked yesterday with a multimeter, to my horror I found that there is 70 Volts between the Neutral and Ground pins on the wall socket. Now all electronic devices are shut down at home (except Laptop) and I am waiting for our electrician for an inspection and solution to the problem. I suggest all FMs please check your wiring at home, this is not child's play for sure. Half of the so called "Electricians" neglect Earthing as they have no clue what it is meant for.

Regarding two-pin power plugs on electronic equipment: this is standard practice nowadays, and protection to the user from electric shock is ensured by a "double insulation" technology.

cheers,
Reji

 

[Thad E Ginathom]

I checked yesterday with a multimeter, to my horror I found that there is 70 Volts between the Neutral and Ground pins on the wall socket.

I don't know how much the numbers actually mean, but I had the same kind of difference in one house. Probably not of any consequence, but I just don't like that tingle. I earthed everything to a metal pipe which went to ground. Had to do that for the turntable anyway, to get rid of the hum.

Two-pin-wired stuff, I suspect, is usually either plastic-cased or double-insulted (IIRC, a square in a square is the EU symbol for that) so one should never get current from the case. Whether a thing sounds good or not is one thing, but the safety aspects should have been taken care of in the design, or it shouldn't be legal to sell.

 

[prankey]

But the question is when you have 2 pin plug without any '+' or '-' marking and when left profile and right profile of that 2pin plug look exactly same, how will you identify the pin meant for phase(+) ?

Sent from my MI MAX using Tapatalk

Like I wrote, we need to trace using hand as usually the cable is flat and we have to trace the right end of it to connect to the right (phase) on the socket (most electricians also ignore that right side should be the phase so please confirm the same for your socket.

 

[markraj]

Hi
Most of the imported 2 pin plugs consists of letters like D,N Etc. In my opinion N stands for neutral.

 

[keith_correa]

Like I wrote, we need to trace using hand as usually the cable is flat and we have to trace the right end of it to connect to the right (phase) on the socket (most electricians also ignore that right side should be the phase so please confirm the same for your socket.

The Right side when one is facing the front of the equipment in question or the Right side when one is facing the back of the equipment?

 

[jls001]

I have not tried hearing difference in plugging two pin connector in two possible ways into wall socket, but I've had disastrous effect of reversed live and neutral at wall socket for washing machine. The control board of the washing machine had blown for the third time. Luckily the local washing machine repair shop detected and knew how to repair that board. The third time it happened I was ready to buy a new machine if it happened a fourth time. The technician who came for repairing on the third occasion did something additional that the previous two didn't do - he checked the phase on the 16A wall outlet and found the live and neutral reversed. He swapped them and the machine is functioning happily now for about one year now. Funnily, I'd noticed the phase reversal long back but didn't bother to correct it as I thought it was of no consequence.

Some equipments are more sensitive to phase reversal, while others are not bothered at all.

By the same token, it is possible that some of us are sensitive to phase reversal in the power supply.

 

[jls001]

One simple way to determine which of the two pins of a captive 2-wire power cord is connected to live is to open the device and do continuity test of the two wires from inside the cabinet to the 2-pin connector that plugs into the electrical socket. Trace the wires inside the cabinet to the connections in the power supply section to determine which one is ground and which one is live. Mark live at the 2-pin end and ensure that it goes to right lower socket hole of 3-pin outlet. Of course this assumes that the 3-pin socket is correctly wired.

 

[Thad E Ginathom]

Like I wrote, we need to trace using hand as usually the cable is flat and we have to trace the right end of it to connect to the right (phase) on the socket (most electricians also ignore that right side should be the phase so please confirm the same for your socket.

Perhaps people should check all their sockets then. It is very important that they are wired correctly. Otherwise, a piece of equipment with its own switch at "off" will not be functioning (also known as not "on" ) but will be live.

An hour or two with a mains-tester screwdriver could save lives. (or cost them --- if people don't know where to stick it!)

 

[prankey]

The Right side when one is facing the front of the equipment in question or the Right side when one is facing the back of the equipment?

Facing back

 

[prankey]

Perhaps people should check all their sockets then. It is very important that they are wired correctly. Otherwise, a piece of equipment with its own switch at "off" will not be functioning (also known as not "on" ) but will be live.

An hour or two with a mains-tester screwdriver could save lives. (or cost them --- if people don't know where to stick it!)

Absolutely buddy. Some switches control Neutral supply and hence socket and connected equipment will still have Live supply even when cut off! Dangerous!!

 

[philipreji]

My electrician found that there was no earth connection at all in two rooms in our flat. He spent half a day to open all power sockets and lay earth wire through the concealed pipes. Now things are fine.

The easiest way to ensure earthing is to use a test lamp. If the lamp lights when connected between the phase and earth pins of a socket, then earthing is fine for that socket. It is a good idea to do this test periodically for sockets on which gadgets like Mixie, grinder, electric iron etc (which have exposed metal parts) are connected. Safety first!

cheers,
Reji

 

[Sean de Silva]

handy devices worth having to check if AC power sockets are wired correctly.

Mx Ac Line Fault Detector - Mx 1177 : Amazon.in: Industrial & Scientific

Mx Ac Line Fault Detector - Mx 1177 : Amazon.in: Industrial & Scientific

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amiciSmart RCD Electric Socket, Automatic Neutral Live Earth Wire Wall Plug Breakage Leakage Tester : Amazon.in: Home Improvement

amiciSmart RCD Electric Socket, Automatic Neutral Live Earth Wire Wall Plug Breakage Leakage Tester : Amazon.in: Home Improvement

www.amazon.in