Neutral prong on Christmas light plug

[DerbyDad03]

I bought a few sets of Philips mini Christmas lights this morning. As I was
putting them on the tree, I noticed something about the plugs and sockets.

1: The plug does not have a wide neutral prong.
2: The socket on the back of the plug will not accept a wide neutral plug
because there is no wide neutral slot.
3: The socket at the end of the string *will* accept a wide neutral plug
since it has a wide neutral slot.

I wonder why that it is. Yes, it allows me to string together lights from
other manufacturers that use a wide neutral plug, but there is no guarantee
that the neutral is actually connected to the neutral because the Philips
plug doesn't force the user to orientate the plug in any given manner.

Why not build the plug and socket at the start of the string with a wide
neutral prong and slot or build the socket at the end without one? Why mix
and match?

[cl...@snyder.on.ca]

Well, the reason for no wide neutral on the "piggyback" is so you
cannot connect a high-power load through the "piggyback" plug. Why
they put it on the end IS a good question - it should NOT be polarized
if the primary connector is not.

[Tony Hwang]

Hi,
I think newer ones seem to have polarized plug/receptacle. Some of old
strings I have are not like that. To mix them, I just snip off wider
blade little bit. For last couple years mixing them, nothing bad happened.

[hr(bob) hofmann@att.net]

I thought by law that all new electrical stuff, unless double-
insulated, had to have polarized plugs. You may have bought some
really old lights.

[DerbyDad03]

I'd be surprised to find that Target is selling "really old lights", but
it's possible. All of their Philips lights (hundred of boxes, all different
quantities and colors) had the same box design, which would mean that
everything that they had on the shelf would have to be really old to be of
the same design vintage.

http://www.target.com/p/philips-remains-lit-100ct-multicolor-mini-string-lights-green-wire/-/A-14092880#prodSlot=large_1_41&term=100
philips mini lights

http://tinyurl.com/Target-Philips-Lights

Besides, even if they were really old, you wouldn't expect to find a
polarized socket on one end would you?

Maybe I'll call Philips tomorrow and inquire.

[home...@home.com]

Or they were made in China, and that stuff dont follow the electrical
codes.

One of the old adaptors to convert a 2 prong outlet to 3 prong grounded
plugs will often fit into those plugs and then the wide prong might fit.
Otherwise, just use a grinder and make the wide prong narrower.

[harry]

If the lights are Chinese, there may well be issues with plugs. It
runs in my mind that there are places in the world with non polarised
sockets similar to yours.

In the UK we have had moulded on plugs that are deadly from China..

[harry]

On Dec 17, 5:28 am, gfretw...@aol.com wrote:
> On Sun, 16 Dec 2012 19:04:54 -0800 (PST), "hr(bob) hofm...@att.net"

> It really has nothing to do with double insulated in this case. The 2
> pin (2 wire) bulbs are not polarized (no screw shell) so there is no
> requirement to polarize the string.

And pointless anyway as they are wired in series.

[DerbyDad03]

<gfre...@aol.com> wrote:

> It really has nothing to do with double insulated in this case. The 2
> pin (2 wire) bulbs are not polarized (no screw shell) so there is no
> requirement to polarize the string.

That doesn't address the question of having a wide slot on the socket at
the end of the string but not on the socket at he plug end.

If you have other sets of lights with a polarized plug (I do) you can't
plug them into the plug end of the Philips sets, you have to plug them into
the socket end, which is not always what I want to do.

[Art Todesco]

I've read all these replies, but I really think I have an answer. I too
have always wondered, but for me I've wondered why are these things
polarized. I think I have an answer. On older light strings, with a
non polar plug, they usually have 2 fuses in the plug so if the plug it
put into the socket in either way, the hot will have a fuse. In
essence, because the lights in the strings are wired in series, the 2
fuses are also in series. But the safety aspect is that if something
shorts to earth ground in the beginning of the string, it should take
out the fuse that's on the hot side, whichever way it is plugged in.
BTW, the second reason for the fusing itself is that in each bulb there
is a shunt which 'activates' when the bulb's filament burns out (opens),
thus keeping the circuit complete and keeping the remaining lamps lit
(if the shunt actually works!). If multiple bulbs in the string burn
out, you can get to a runaway situation where more and more current
flow, burning out more and more lamps until all that is left is shunts.
The fuse(s) protect against the large currents causing bad things to
happen with the bulbs and/or wiring. But, of course, for this case only
one fuse is needed. So, to save on putting in the 2nd very cheap fuse,
they only put one fuse on the hot side and use polar plug to guarantee
it. BTW, some older strings had 2 special bulbs, which were called
'fuse bulbs' which apparently didn't have shunts and usually had some
green paint on the bulb. They usually had a different base, so a
regular lamp could not be plugged in these special sockets. But these
seem to have disappeared through the years. So now, we seem to be
stuck with this polar stuff. A small file or a moto tool works wonders,
but I always make sure they are plugged in the 'right' way .... yeah sure :)

[Bill]

In article <1310476926377401614.235313teamarrows-
ezne...@nntp.aioe.org>, teama...@eznet.net says...

Things made in China frequently have "little problems" like this. Either
because they can't read U.L electrical standards which are in English,
or because they just don't care.

Report the product to the US Consumer Product Safety Commission. They
already have tons of recalls on Chinese made electrical products which
are counterfeit or unsafe. This will add to the list...

Here is an example of WHY plugs are polarized - makes changing a regular
light bulb safer...
http://www.familyhandyman.com/DIY-Projects/Electrical/Electrical-
Repair/wiring-a-plug-replacing-a-plug-and-rewiring-electronics/View-All

[Mark Lloyd]

On 12/17/2012 08:06 AM, Art Todesco wrote:

[snip]

BTW, some older strings had 2 special bulbs, which were called
> 'fuse bulbs' which apparently didn't have shunts and usually had some
> green paint on the bulb. They usually had a different base, so a
> regular lamp could not be plugged in these special sockets. But these
> seem to have disappeared through the years.

I don't remember any with green paint. I do remember 'flasher' bulbs
with red paint. IIRC, those didn't have shunts.

[snip]

--
8 days until the winter celebration (Tue Dec 25, 2012 12:00:00 AM for 1
day).

Mark Lloyd
http://notstupid.us

"The Church preaches love, but in its heyday tortured and burned people.
The injunction is symbolized by Orwell's "Ministry of Love", which is
the torture and liquidation bureau." -- Richard A. Posner

[cl...@snyder.on.ca]

On Sun, 16 Dec 2012 19:04:54 -0800 (PST), "hr(bob) hof...@att.net"
<hrho...@att.net> wrote:

A string of lights has no "chassis" or anything to reference to
neutral, so no polarization is required.

[cl...@snyder.on.ca]

On Mon, 17 Dec 2012 09:06:36 -0500, Art Todesco <acto...@yahoo.com>
wrote:

Never seen a fuse in the plug of an "american style" plug - ot ANY
115 volt plug, for that matter.

[Pat]

> Never seen a fuse in the plug of an "american style" plug - ot ANY
>115 volt plug, for that matter.

Then you haven't purchased cheap Christmas lights recently. They all
have them and usually include spares in with the spare bulbs. They
are tubes of glass with metal on the ends - just like fuses you may be
used to but much smaller. I don't have any here, but from memory,
they are about 1/2 inches long. I have never had to use one, though.

[DerbyDad03]

On Dec 17, 12:21 pm, cl...@snyder.on.ca wrote:
> On Mon, 17 Dec 2012 09:06:36 -0500, Art Todesco <actode...@yahoo.com>

> 115 volt plug, for that matter.- Hide quoted text -
>
> - Show quoted text -

Christmas lights strings have had fuses built onto the plug for many
years. There is a small slide out panel in the plug that reveals the
fuses.

See here...

http://www.bethlehem-lights.com/images/fuse.gif

[DerbyDad03]

On Dec 17, 9:06 am, Art Todesco <actode...@yahoo.com> wrote:
> On 12/16/2012 9:11 PM, DerbyDad03 wrote:
>
>
>
> > I bought a few sets of Philips mini Christmas lights this morning. As I was
> > putting them on the tree, I noticed something about the plugs and sockets.
>
> > 1: The plug does not have a wide neutral prong.
> > 2: The socket on the back of the plug will not accept a wide neutral plug
> > because there is no wide neutral slot.
> > 3: The socket at the end of the string *will* accept a wide neutral plug
> > since it has a wide neutral slot.
>
> > I wonder why that it is. Yes, it allows me to string together lights from
> > other manufacturers that use a wide neutral plug, but there is no guarantee
> > that the neutral is actually connected to the neutral because the Philips
> > plug doesn't force the user to orientate the plug in any given manner.
>
> > Why not build the plug and socket at the start of the string with a wide
> > neutral prong and slot or build the socket at the end without one? Why mix
> > and match?
>
> I've read all these replies, but I really think I have an answer.  I too
> have always wondered, but for me I've wondered why are these things
> polarized.  I think I have an answer.  On older light strings, with a
> non polar plug, they usually have 2 fuses in the plug so if the plug it
> put into the socket in either way, the hot will have a fuse.

When you say "older light strings", what do you mean?

I bought the lights with the non-polarized plug at Target yesterday.
How long would they have to have been in their warehouse to be what
yopu consider "older"?

(BTW...I kind of agree with what you are saying, except for the
"older" part. I don't really think that I bought "older" light
strings, but I could be wrong.)

Of course, none of what you've said seems to answer my original
question - if they don't use a polarized plug or socket at the start
of the string, why do they use a polarized socket at the end?

> In
> essence, because the lights in the strings are wired in series, the 2
> fuses are also in series.  But the safety aspect is that if something
> shorts to earth ground in the beginning of the string, it should take
> out the fuse that's on the hot side, whichever way it is plugged in.
> BTW, the second reason for the fusing itself is that in each bulb there
> is a shunt which 'activates' when the bulb's filament burns out (opens),
> thus keeping the circuit complete and keeping the remaining lamps lit
> (if the shunt actually works!).  If multiple bulbs in the string burn
> out, you can get to a runaway situation where more and more current
> flow, burning out more and more lamps until all that is left is shunts.
>   The fuse(s) protect against the large currents causing bad things to
> happen with the bulbs and/or wiring.  But, of course, for this case only
> one fuse is needed.   So, to save on putting in the 2nd very cheap fuse,
> they only put one fuse on the hot side and use polar plug to guarantee
> it.  BTW, some older strings had 2 special bulbs, which were called
> 'fuse bulbs' which apparently didn't have shunts and usually had some
> green paint on the bulb.  They usually had a different base, so a
> regular lamp could not be plugged in these special sockets.  But these
> seem to have disappeared through the years.   So now, we seem to be
> stuck with this polar stuff.  A small file or a moto tool works wonders,

> but I always make sure they are plugged in the 'right' way .... yeah sure :)- Hide quoted text -

[Art Todesco]

Actually, I've never seen that and I have lots of light strings of
various age and lengths. That's just plain wrong. I don't know how it
could have been UL approved.

[cl...@snyder.on.ca]

Where are you buying these - and when you say cheap, how cheap?

Never seen one in Ontario Canada at Canadian Tire or Home Hardware or
Walmart (have not looked very hard at Walmart - I try not to patronize
them).

[cl...@snyder.on.ca]

None on any of my Noma light strings. None on the Cheapie Canadian
Tire strings I have left around either -and none on the light strings
on the old pre-lit tree (3 years old?) we gave to my daughter this
year either.

We've gone to 12 volt LED pre-lit this year - running off a 12 volt
switch-mode power supply.. So like I said, I've never seen one "in
the flesh" - the link above is the first I've seen, so it would appear
to be far from universal. Virtually every one I've seen has a
monolythic injection moulded plug - solid plastic through and through.

[cl...@snyder.on.ca]

On Mon, 17 Dec 2012 17:26:19 -0500, Art Todesco <acto...@yahoo.com>
wrote:

Simple. They print the labels in China and put them on - what do you
mean "approved"???