Which side of an electrical outlet should be Neutral?

Technical Questions & Discussions about Computers, IT & electronics.
User avatar
rickfarang
udonmap.com
Posts: 2394
Joined: January 1, 2006, 6:01 am
Location: Udon Thani

Which side of an electrical outlet should be Neutral?

Post by rickfarang » February 2, 2011, 5:30 pm

Everywhere I look, the if you look at a three pronged outlet with the ground connection pointing down,the slot on the left is Neutral. Everywhere. Everywhere except for some outlets I bought from Global recently. On them the slot on the left is marked "L" and the slot on the right is marked "R". And both slots are the same size.

My house was wired such that the slot to the left of the ground connection is Neutral.

Since this involves safety, and I don't believe one should dismiss off such matters without understanding them, I ask whether anybody can explain the apparent swap on the new outlets.

An image depicting the connector with Neutral on the left can be seen at the URL below;
http://img14.imageshack.us/i/1111wim.jpg/

Thank you in advance.



User avatar
Bandung_Dero
udonmap.com
Posts: 3614
Joined: July 10, 2005, 8:53 am
Location: Ban Dung or Perth W.A.

Re: Which side of an electrical outlet should be Neutral?

Post by Bandung_Dero » February 2, 2011, 8:18 pm

Looking at the socket Active (Line) should be on the left Neutral on the right and Earth below. That applies to most of SE Asia including Aust and NZ. BUT in saying that Thailands power system is so fu#ked up anything could apply.

I installed double poled circuit breakers in my home because at the time Neutral was floating at 50 VAC above ground. We do not have a MEN system here (Multiple Earth Neutral). I placed my Actives (line) on the left so at least I would not be confused, all my GPO's have a strong Earth and RCD protection.

http://www.accesscomms.com.au/reference/powerplug.htm

User avatar
rickfarang
udonmap.com
Posts: 2394
Joined: January 1, 2006, 6:01 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by rickfarang » February 2, 2011, 10:08 pm

Its only more puzzling now. Is Australia different from much of the world? Maybe I some Australian outlets. See: Puzzling :)

User avatar
Alchai
udonmap.com
Posts: 257
Joined: January 26, 2009, 8:06 pm
Location: In the boat

Re: Which side of an electrical outlet should be Neutral?

Post by Alchai » February 3, 2011, 1:31 am

rickfarang wrote:Everywhere I look, the if you look at a three pronged outlet with the ground connection pointing down,the slot on the left is Neutral. Everywhere. Everywhere except for some outlets I bought from Global recently. On them the slot on the left is marked "L" and the slot on the right is marked "R". And both slots are the same size.

My house was wired such that the slot to the left of the ground connection is Neutral.

Since this involves safety, and I don't believe one should dismiss off such matters without understanding them, I ask whether anybody can explain the apparent swap on the new outlets.

An image depicting the connector with Neutral on the left can be seen at the URL below;
http://img14.imageshack.us/i/1111wim.jpg/

Thank you in advance.
As you are dealing with AC (alternated current) here it is not important how live and neutral are connected. However, you must not connect earth to any of these!

User avatar
Bandung_Dero
udonmap.com
Posts: 3614
Joined: July 10, 2005, 8:53 am
Location: Ban Dung or Perth W.A.

Re: Which side of an electrical outlet should be Neutral?

Post by Bandung_Dero » February 3, 2011, 5:07 am

It's basically a nightmare see this site, covers most of the world.

http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » February 3, 2011, 7:40 am

Alchai

The location of neutral and positive are important when using a light bulb or appliance etc. See below:

PolarizationPolarized plugs and sockets are those designed to connect only in one orientation, so the live and neutral conductors of the outlet are connected (respectively) to the live and neutral poles of the appliance. Polarization is maintained by the shape, size, or position of plug pins and socket holes to ensure that a plug fits only one way into a socket. The switch of the appliance is then put in the live wire. If the neutral wire were interrupted instead, the device would be deactivated but its internal wiring would still be live. This is a shock hazard; if the energized parts are touched, current travels to earth through the body. Devices that especially present this hazard include toasters and other appliances with exposed heating elements, which with reversed polarity can remain live even when they are cool to the touch. Screw-in light bulbs with reversed polarity may have exposed portions of the socket still energized even though the lamp is switched off. Transposition of the live and neutral wires in the wiring to sockets defeats the safety purpose of polarized sockets and plugs; a circuit tester can be used to detect swapped wires.

Unpolarized plugs and sockets are those which can connect either way around, so live and neutral wires are connected arbitrarily. Unpolarized plug/socket systems such as the Europlug rely on device construction requirements to avoid the shock hazards created by interchange of live and neutral connections

User avatar
FrazeeDK
udonmap.com
Posts: 4909
Joined: February 13, 2006, 2:02 am
Location: Udon Thani Thailand

Re: Which side of an electrical outlet should be Neutral?

Post by FrazeeDK » February 3, 2011, 7:17 pm

3 prong polarization testers are available.. You plug it into a standard 3 prong outlet and the lights on it show you if the socket is wired "backwards".. After having our place built I found over half the sockets "backwards" and had an electrician correct them.. A few years later I wondered if having light outlets, fans, or AC units wired "backwards" would effect performance of bulb life.. When I replaced quickly burned out incadescent bulbs with more modern screw in fluorescents, my burn-out rate when done significantly...

User avatar
Alchai
udonmap.com
Posts: 257
Joined: January 26, 2009, 8:06 pm
Location: In the boat

Re: Which side of an electrical outlet should be Neutral?

Post by Alchai » February 4, 2011, 6:01 pm

fdimike wrote:Alchai

The location of neutral and positive are important when using a light bulb or appliance etc. See below:

PolarizationPolarized plugs and sockets are those designed to connect only in one orientation, so the live and neutral conductors of the outlet are connected (respectively) to the live and neutral poles of the appliance. Polarization is maintained by the shape, size, or position of plug pins and socket holes to ensure that a plug fits only one way into a socket. The switch of the appliance is then put in the live wire. If the neutral wire were interrupted instead, the device would be deactivated but its internal wiring would still be live. This is a shock hazard; if the energized parts are touched, current travels to earth through the body. Devices that especially present this hazard include toasters and other appliances with exposed heating elements, which with reversed polarity can remain live even when they are cool to the touch. Screw-in light bulbs with reversed polarity may have exposed portions of the socket still energized even though the lamp is switched off. Transposition of the live and neutral wires in the wiring to sockets defeats the safety purpose of polarized sockets and plugs; a circuit tester can be used to detect swapped wires.

Unpolarized plugs and sockets are those which can connect either way around, so live and neutral wires are connected arbitrarily. Unpolarized plug/socket systems such as the Europlug rely on device construction requirements to avoid the shock hazards created by interchange of live and neutral connections
fdimike
This text is a copy/paste from Wikipedia. Maybe I have been livig with the idea that all electrical circuits and systems work the same worldwide. As you can see I am only familiar with unpolarized plugs and sockets (Eurosystem). If there is another system used in Thailand I have been unaware of that.

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » February 4, 2011, 7:08 pm

I realize it came out of Wikipedia. I simply wanted to point out the reason for polarized electrical systems and this explanation was easy to understand. The electrical code in the US mandates polarized plugs on all appliances, lamps etc for safety reasons just as it mandates a grounded (earthed) electrical plug on all major appliances, computers etc. I would think adding this level of safety would be a good thing here in Thailand considering the poor state of the elctrical system. Safety is just not a part of the Thai vocabulary.

User avatar
Alchai
udonmap.com
Posts: 257
Joined: January 26, 2009, 8:06 pm
Location: In the boat

Re: Which side of an electrical outlet should be Neutral?

Post by Alchai » February 4, 2011, 8:37 pm

So if I want to plug in an electrical appliance, say a lamp, how do I know which way to plug it in to ensure live commects to live and neutral to neutral being a 2 pin plug?

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » February 4, 2011, 8:55 pm

If the plug is polarzed it will have 1 blade wider than the other. Assuming the electrical outlet is wired correctly all will be ok as the plug will only go in one way. If both blades of the plug are the same then you can look at the wire. If it is typical 2 part lamp wire then one of the parts will have some printing on it concerning the wire rating. The part with the writing is normally the neutral wire. However, here in Thailand normal may not apply! A better way is to use a volt ohm meter to test continuity.

User avatar
tamada
udonmap.com
Posts: 17213
Joined: February 21, 2007, 4:03 am
Location: Down two...then left

Re: Which side of an electrical outlet should be Neutral?

Post by tamada » February 8, 2011, 11:11 am

All this talk of polarised plugs and sockets and polarity testing outlets... in Thailand.... LOL

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » February 8, 2011, 11:46 am

Tamada

All this talk as you say is valuable safety related information. You can choose to either implement it or ignore it. I personally value my life enough to spend the few minutes it takes to make sure the electricty in my home is operating correctly.

mortiboy
udonmap.com
Posts: 3104
Joined: April 25, 2008, 8:59 pm
Location: Guildford/Udon

Re: Which side of an electrical outlet should be Neutral?

Post by mortiboy » February 19, 2011, 10:47 am

Competent Electrician needed!
Friend here Udon needs a Electrician to sort out his wiring in the loft
He says wires need relaying tidy, and neatly in order. All working OK no faults just a tidy up.
At the moment says in a shamble.

User avatar
hangsaboot
udonmap.com
Posts: 443
Joined: September 11, 2009, 6:40 pm

Re: Which side of an electrical outlet should be Neutral?

Post by hangsaboot » February 19, 2011, 2:46 pm

tamada wrote:All this talk of polarised plugs and sockets and polarity testing outlets... in Thailand.... LOL

a friend of mine was recently , fatally electrocuted while taking a shower
in a hotel in the phillipenes .
the sooner we have electrical safety standards and
competent electricians the better .

many chancers end up in the cemetry . :(
thats a shock for you .

User avatar
Alchai
udonmap.com
Posts: 257
Joined: January 26, 2009, 8:06 pm
Location: In the boat

Re: Which side of an electrical outlet should be Neutral?

Post by Alchai » February 19, 2011, 4:28 pm

fdimike wrote:If the plug is polarzed it will have 1 blade wider than the other
I haver never seen a polarised plug in Thailand. Maybe someone here can explain a little better what one should do for good safety praxis in Thailand.

jimboLV
udonmap.com
Posts: 863
Joined: May 3, 2009, 12:31 pm
Location: Amnat Charoen

Re: Which side of an electrical outlet should be Neutral?

Post by jimboLV » February 19, 2011, 5:29 pm

I just bought a Samsung refrigerator , 9 cf so not a 'lil' feller'. Not only does it NOT have a grounded plug, but the two pronged plug is not even polarized! Yet the instruction manual goes on and on about how it should be grounded for safety. :? Granted the English instruction manual downloaded was from Malaysia, as the Thai refrigerators only have instructions in Thai, but it appears to be the same model. Could it be that the models sold in Thailand are double insulated, thus not needing grounding? Doubtful. We also bought a Samsung Wash machine, which does have a three pronged plug. I then checked all the appliances and extension cords in the house, and none of those without grounded plugs were polarized. So you can bet that if I'm going to work on anything electrical around the house, the power will be shut off at the main.

We just moved into our newly constructed home and all the outlets are grounded with the common (neutral) on the left. I don't know if this is standard practice since I told the electrician to do it that way and that I would be checking it. I did check and they were all wired correctly. Unlike a new home I bought in the US where I found two outlets where the ground wasn't connected and one where the polarity was wrong.

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » February 19, 2011, 7:13 pm

I have a large Hitachi refrigerator without a 3 prong or polarized plug. I solved the problem by changing the plug to a 3 prong version. A good rule of thumb in determining which wire is supposed to be hot (positive) and which is neutral is to look at the wire. If the wire is flat with two seperate lines look for some printing on the wire. The line with the printing should be the neutral line. I then added a new ground line securing it with zip ties along the way from the refrigerator to the plug. The fix works like a champ.

Washing machines are typically more dangerous then refrigerators as you are mixing electricty with water. It's really essential the washer be grounded to avoid receiving an unnecessary shock when reaching into the washer in bare feet.

Here's a great web site for all to read about electricity here in Thailand:

http://www.thailandguru.com/electricity ... iland.html

Hope this helps.

bluejets
udonmap.com
Posts: 1059
Joined: March 17, 2008, 10:05 am
Location: Australia

Re: Which side of an electrical outlet should be Neutral?

Post by bluejets » March 1, 2011, 1:13 pm

It doesn't make any difference which side is active or neutral. In Aus the only reason they have active on a selected side is because a switch is used in the active conductor and if wired ar..about then the switch is operating in the neutral which is illegal here. Obviously because they want the switch to cut supply.

fdimike
udonmap.com
Posts: 1876
Joined: July 7, 2005, 10:11 am
Location: Udon Thani

Re: Which side of an electrical outlet should be Neutral?

Post by fdimike » March 1, 2011, 1:28 pm

Apparently AU doesn't have as tough an electrical code as the US. There is a logical reason for keeping all the hot (active/positive) lines aligned. Maybe a re-read of the website might make it clearer.

Post Reply

Return to “Computers, IT & Electronics”