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[frank kayser]

I was looking for what I thought would have been an a simple answer to a simple question.  Seems neither are simple.  On an IEC C14 panel connector, which side is hot, and which side is neutral? 

Much has changer over the years since Fender design where they were the power switch switched not the hot, but switched the neutral to turn the amp on and off. They also deployed the polarity switch and the "death cap".  I'm guessing modern circuits switch both the neutral and hot these days.  I would like to put it back as I found it.  Of course, if the wall outlet had hot and neutral reversed, how the socket is wired would be moot.
 
Some of the confusion is that the C14 is a multi-purpose, international connector, each with varying color codes, use for both 120v and 240v applications.
Some confusion comes from "language", not so much German, Spanish, or regional languages, but the use of words like plug and socket.

Part of the problem is one of definition I've had personally.  Male vs female connectors.  For example, one can see the outer, smaller shell plugging into another larger connector shell could be characterized as male to female connection.  Now I know it is not.  It is about the pins, not the shell.  Pins are male.

In case of NEMA, they use plug and receptacle - that logically translates to male and female parts of the connection.

Just as I was writing this, I came across this: IEC 60320 Reference Information.
https://shop.worldcordsets.com/shop/reference-materials/iec-60320-reference-chart

This adds some official clarity of terms - from the  reference "Each Plug, Connector, Inlet is unique and can only be mated with a component with comparable voltage and amperage ratings. One consistent distinction between the names of each, is the male is an even number and the female is an odd number.

"Unfortunately, they use three terms, not two, in the bolded section above.  The document does explain the use of odd and even numbers. (second bold section), but fails to link Plug to Male, and Inlet to female - for good reason.  We can agree that exposed pins, blades, etc are never energized, except when in a safe female device.  Otherwise, death is not far away.

IEC C13 is at times a female cord-end device that supplies power to computers, amps, mixers, etc.  Most would refer to this device as a plug.  Contrast that to a NEMA 5-15p for example - one "plug" is male, built "P" into its name, and one device, many of us also call a plug, is female.  NEMA calls the other 5-15r end a receptacle, where the we would assume panel-mount C14 an inlet, receptacle, or socket.  And what is a connector? A C13/C14 pair?

This male-female, plug/inlet connector receptacle and socket language makes finding information on the web, shall we say, interesting. One answer to a the question started along the lines of the "socket, being female...".  Furthermore just about every explanation includes a picture - one being a C13 head on, and one being a C14 head on.  Hello, they both look the same from that angle!  Of course since they all look the same, one of the drawings or explanations had to be right - like a stopped analog clock being right twice a day.

Of course, a 120v circuit most likely has 120v hot, and 0v on the neutral, while 230v would have 115v on the hot, and 115v on the neutral.  To further confuse the matter, the small Honda gennies put 60v on hot, and 60v on neutral.

My conclusion regarding the C13/C14 wiring, it appears there is not a "right" answer.  It appears it does not matter which side is wired hot. 

However I did get a clue on how *some* cords are wired from a picture of a C13 end that was marked "H" and ground.  Still a bit concerned, I plugged in an "IEC cable"  and with a neon tester, found which side was hot.  I wired the plug accordingly.


However, this entire exercise was a circular waste of time.  Thought I'd share.
frank

[Mike Caldwell]

As you look at a IEC inlet with the with the middle pin at the top left to right
is.... hot/line  - ground - neutral.

[Geoff Doane]

My conclusion regarding the C13/C14 wiring, it appears there is not a "right" answer.  It appears it does not matter which side is wired hot. 

I would agree that "properly" (safely) designed equipment should not matter which side is hot, but I did a quick survey of four IEC female cordsets that were sitting around my shop, and not plugged into anything at the moment.  All four of them had the sockets marked L, N and [the electronic symbol for ground], in the order that Mike described them, so it looks like the answer to your question (was there a question?) is readily available.

GTD

[Kevin Graf]

If the AC power line has a Hot & Neutral, then the switch & fuse must be on the Hot line.
If both the Hot & Neutral are switched, it must be a interlinked double switch.
If both the Hot & Neutral have a circuit breaker, it must be a interlinked double circuit breaker.
Two independent fuses are not permitted.

[Daniel Levi]

Double pole fusing was common in the early days of electricity in Britain, of course it can cause the issue of the neutral side fuse failing but not the live side fuse, creating the dangerous situation where you think a circuit/appliance is dead and thus safe and it isn't.

As for wiring an IEC C14 connector on a Volex power lead I have here that is marked with the polarity on the face of the female (C13) connector it states that with the earth contact at the top, neutral is to the left and live/hot is to the right.
So looking from the back of a C14 (male) connector the wiring would be the same (Neutral left, live right, with the earth facing up). 

[frank kayser]

Thanks, guys.  That's the conclusion I came to, but it befuddled me that information, and that information consistently, was so difficult to extract from the internet.
Not so much a question but a series of observations as I made the journey.  So be it.

[Jonathan Johnson]

In my opinon, any device that uses an IEC C13/C14 power connection, especially if it's a multivoltage power supply and equipped with a line switch, should have a double-pole switch that opens both lines simultaneously.

The reason is that in North America, if the device is connected to a 208V or 240V power supply, then both sides are "hot" relative to ground. Opening only one line could still leave components energized.

If it's not equipped with a switch (or a "death"/stinger cap), which one is neutral and which one is line/live/hot should be irrelevant.

[Jeff Bankston]

The larger blade/slot is always suppose to be the ground. The next larger blade/slot is always suppose to be the neutral. The smallest blade(s)/slots(s) are suppose to be the hot. This is so its foolproof or suppose to be and the ground connection has the largest connection followed by the neutral. The hot is never suppose to be on the largest connection. On all the connectors I had ever wired the ground blade/slot screw is always green color. The neutral silver. The hot gold. Always check how a device is wired if in doubt. I am a retired commercial journey/foreman electrician.

[Steve M Smith]

The larger blade/slot is always suppose to be the ground. The next larger blade/slot is always suppose to be the neutral. The smallest blade(s)/slots(s) are suppose to be the hot.

Live and neutral are the same size for IEC.







Steve.

[John Roberts {JR}]

I was looking for what I thought would have been an a simple answer to a simple question.  Seems neither are simple.  On an IEC C14 panel connector, which side is hot, and which side is neutral? 

Much has changer over the years since Fender design where they were the power switch switched not the hot, but switched the neutral to turn the amp on and off. They also deployed the polarity switch and the "death cap".  I'm guessing modern circuits switch both the neutral and hot these days.  I would like to put it back as I found it.  Of course, if the wall outlet had hot and neutral reversed, how the socket is wired would be moot.
 
Some of the confusion is that the C14 is a multi-purpose, international connector, each with varying color codes, use for both 120v and 240v applications.
Some confusion comes from "language", not so much German, Spanish, or regional languages, but the use of words like plug and socket.

Part of the problem is one of definition I've had personally.  Male vs female connectors.  For example, one can see the outer, smaller shell plugging into another larger connector shell could be characterized as male to female connection.  Now I know it is not.  It is about the pins, not the shell.  Pins are male.

In case of NEMA, they use plug and receptacle - that logically translates to male and female parts of the connection.

Just as I was writing this, I came across this: IEC 60320 Reference Information.
https://shop.worldcordsets.com/shop/reference-materials/iec-60320-reference-chart

This adds some official clarity of terms - from the  reference "Each Plug, Connector, Inlet is unique and can only be mated with a component with comparable voltage and amperage ratings. One consistent distinction between the names of each, is the male is an even number and the female is an odd number.

"Unfortunately, they use three terms, not two, in the bolded section above.  The document does explain the use of odd and even numbers. (second bold section), but fails to link Plug to Male, and Inlet to female - for good reason.  We can agree that exposed pins, blades, etc are never energized, except when in a safe female device.  Otherwise, death is not far away.

IEC C13 is at times a female cord-end device that supplies power to computers, amps, mixers, etc.  Most would refer to this device as a plug.  Contrast that to a NEMA 5-15p for example - one "plug" is male, built "P" into its name, and one device, many of us also call a plug, is female.  NEMA calls the other 5-15r end a receptacle, where the we would assume panel-mount C14 an inlet, receptacle, or socket.  And what is a connector? A C13/C14 pair?

This male-female, plug/inlet connector receptacle and socket language makes finding information on the web, shall we say, interesting. One answer to a the question started along the lines of the "socket, being female...".  Furthermore just about every explanation includes a picture - one being a C13 head on, and one being a C14 head on.  Hello, they both look the same from that angle!  Of course since they all look the same, one of the drawings or explanations had to be right - like a stopped analog clock being right twice a day.

Of course, a 120v circuit most likely has 120v hot, and 0v on the neutral, while 230v would have 115v on the hot, and 115v on the neutral.  To further confuse the matter, the small Honda gennies put 60v on hot, and 60v on neutral.

I am not the wiring terminology expert but I think I have seen 240 hot legs called L1 and L2, neutral is historically bonded to ground at the panel. Old school 240V wiring may have even included a neutral and a ground. IIRC when I installed my wall oven it had two hots and a neutral terminal tied to chassis ground. I tried to hire an electrician to wire in a proper 4 wire power drop, but he never answered my phone calls, so I ended up wiring in my oven myself. (don't tell anybody).

 

My conclusion regarding the C13/C14 wiring, it appears there is not a "right" answer.  It appears it does not matter which side is wired hot. 

However I did get a clue on how *some* cords are wired from a picture of a C13 end that was marked "H" and ground.  Still a bit concerned, I plugged in an "IEC cable"  and with a neon tester, found which side was hot.  I wired the plug accordingly.


However, this entire exercise was a circular waste of time.  Thought I'd share.
frank

From my experience with UL specs they tend to treat hot and neutral as if both are energized. They are both current carrying conductors.

JR

[Steve M Smith]

I am not the wiring terminology expert but I think I have seen 240 hot legs called L1 and L2, neutral is historically bonded to ground at the panel. Old school 240V wiring may have even included a neutral and a ground.

Is that because your 240v supply is cente tapped neutral to give two 120v supplies? In the UK, the 230v supply is one of three phases in a star formation with a central neutral which is bonded to ground.


Domestic properties get one of the three phases, industrial properties get all three.




Steve.

[Daniel Levi]

Is that because your 240v supply is cente tapped neutral to give two 120v supplies? In the UK, the 230v supply is one of three phases in a star formation with a central neutral which is bonded to ground.


Domestic properties get one of the three phases, industrial properties get all three.




Steve.

I believe, despite not being American, that this is in fact the case with 240V being 2x120V one being 180° out of phase compared to the other one, plus unlike our British sockets which are always polarised on the plug/socket side some American 2 prong plugs aren't (similar to Schuko/Italian 3 prong and two prong plugs on the continent.
Note that they can also have 208V on the same outlets in places like apartment blocks and business where the 208V supply is derived from a 3 phase supply and devices are designed to accept either voltage.

Makes our electrical supply seem simple even with our ring final circuits, esp. given the amount of different plugs/sockets they have over there, esp. in the higher power variants. (noting that we have only one common type of domestic outlet with all industrial outlets generally being of the same series of industrial connectors)

[Stephen Swaffer]

I believe, despite not being American, that this is in fact the case with 240V being 2x120V one being 180° out of phase compared to the other one, plus unlike our British sockets which are always polarised on the plug/socket side some American 2 prong plugs aren't (similar to Schuko/Italian 3 prong and two prong plugs on the continent.
Note that they can also have 208V on the same outlets in places like apartment blocks and business where the 208V supply is derived from a 3 phase supply and devices are designed to accept either voltage.

Makes our electrical supply seem simple even with our ring final circuits, esp. given the amount of different plugs/sockets they have over there, esp. in the higher power variants. (noting that we have only one common type of domestic outlet with all industrial outlets generally being of the same series of industrial connectors)

This is correct.  Our system does allow a lower voltage to ground-which on the surface would seems to be a little safer.  I am sure there are statistics out there to prove or disprove this-in any case, it really is a moot point given the installed base-changing would be very impractical.  New receptacles are polarized-I would guess that goes back at least 50-60 years given what I see in homes.

[Daniel Levi]

This is correct.  Our system does allow a lower voltage to ground-which on the surface would seems to be a little safer.  I am sure there are statistics out there to prove or disprove this-in any case, it really is a moot point given the installed base-changing would be very impractical.  New receptacles are polarized-I would guess that goes back at least 50-60 years given what I see in homes.

One little oddity in Britain is power for worksites, these generally use 110V power (using 16A yellow IEC60309 connectors) supplied by an isolation transformer that is wired to give 55V on both the live and neutral pins, this allows for extra safety as not only are you isolated from the mains but if you come into contact with a conductor then it's only 55V between you and ground (assuming you don't come between both conductors).

The only other plugs in common use are 15A round pin plugs for stage lighting (used primarily due to the lack of a fuse, as a fuse failing up high is a PITA), the smaller 5A and 2A variants for portable/desk lighting either where it is centrally switched or to prevent normal devices being used in said sockets (hotels and university accommodation being common users).

There are also special plugs with T shaped earths for special medical equipment and such like plus Walsall Gauge plugs that were used primarily by users who wanted to stop unauthorised appliances being used, the BBC for example were one such user ad so were London Underground for 110V supplies.

See more here: https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets:_British_and_related_types

[John Roberts {JR}]

Is that because your 240v supply is cente tapped neutral to give two 120v supplies?

typically residential power drops in the US are a center tapped transformer winding, from step down transformer mounted on the power pole.

Indeed the center tap is bonded to neutral and earth ground, at the service panel. The two opposite polarity (same phase) ends of the centre tapped transformer winding feed banks of 120V branches. If these loads are not well balanced for current draw, significant current can flow in the neutral/center tap. If a wiring fault opens that neutral/center tap bond, the voltage will sag on the heavily loaded side, and voltage will rise on the lightly loaded side still adding up to the 240V total across the winding.   

In the UK, the 230v supply is one of three phases in a star formation with a central neutral which is bonded to ground.

in the US the high voltage distribution uses three phases, while residential power drops generally pull from only a single phase of those three. Heavy commercial users draw power from all three phases.

Domestic properties get one of the three phases, industrial properties get all three.




Steve.

Yup same here...  Just to be pedantic the two polarities of residential 120V power are the same one phase....

JR

PS: Balanced power +/- 60V AC is sometimes used in studios to reduce electrostatic fields. The worker safety issue, should help, but I'll take RCD/GFCI any day.

[Jeff Bankston]

Live and neutral are the same size for IEC.







Steve.

Yes I know but the end that plugs into the wall will only go one way with the ground pin in place. You can continuity the ends and find which blade is the one that goes into the small slot and that will be the hot on the other end providing that the wall outlet is wired correctly. Some outlest are installed with the ground pin down and some with the ground pin up and some sideways. It probably doesnt matter on the equipment end unless someone wanted the equipment wired a certain way. It will not matter if its a 220V piece of equipment.

[Jonathan Johnson]

The larger blade/slot is always suppose to be the ground. The next larger blade/slot is always suppose to be the neutral. The smallest blade(s)/slots(s) are suppose to be the hot. This is so its foolproof or suppose to be and the ground connection has the largest connection followed by the neutral. The hot is never suppose to be on the largest connection. On all the connectors I had ever wired the ground blade/slot screw is always green color. The neutral silver. The hot gold. Always check how a device is wired if in doubt. I am a retired commercial journey/foreman electrician.

Jeff, I know that (in the US at least) the screws are supposed to denote the wire function. But, ever since I found a brand new receptacle with the silver screw on the narrow slot and the brass screw on the wide slot (someone at the factory screwed up), I've never trusted the screw colors. I always look at the face of the receptacle (or the prongs of the plug) and wire according to position.

[Steve M Smith]

I always look at the face of the receptacle (or the prongs of the plug) and wire according to position.

It's just something else to learn, like which is pin one when soldering an XLR.




Steve.

[Brian Jojade]

On Edison plugs, it's easier to determine hot neutral and ground because the pins are different sizes or shapes.  The round plug is ground, the bigger pin is neutral and the smallest is hot.

The C14 uses 3 pins the same size, so now you have to go on memory.

But, handily, the pins are in the exact same position as they would be on an Edison plug. So grab the Edison plug for reference and you can figure it out from there.

[ProSoundWeb Community]