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SuperNet9
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join:2002-10-08
Schaumburg, IL
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3 edits

Christmas lights power questions..

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I am going to use 8 boxes of 50 string led lights, hooked up to a Socket Adapter (see attached pic).. Is that OK?

Or what I have now is , 4 boxes of 100 string mini lights hooked up to a Socket Adapter (see attached pic).. Is that OK?

Another question, I want to hook up 2 Median size snow men, that have a light bulb that is 7w.. Can I hook them up to the safely to the LED/ or mini lights end (see attach pic) that will go to the same Socket Adapter?
I have to trim the snow men power plug because the metal plug is a tiny bit wider than the hole on the Xmas light plug.

What's the max watts I can hook up to the Socket Adapter? I'm guessing 100watt since its going to a light bulb socket?

Also, If yes, I had to trim the power plug to fit into the LED socket.. Is that OK? ( see attached pic)
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robbin
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join:2000-09-21
Leander, TX
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2 recommendations

You should not be making modifications to any plugs.

bemis

join:2008-07-18
Reading, MA
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2 recommendations

reply to SuperNet9
said by SuperNet9:

I have to trim the snow men power plug because the metal plug is a tiny bit wider than the hole on the Xmas light plug.
...
Also, If yes, I had to trim the power plug to fit into the LED socket.. Is that OK? ( see attached pic)

Do you mean you trimmed off the polarization part of the plug? That isn't OK. That bit you trimmed off is what is supposed to guarantee you have the hot and neutral sides of the device correctly connected, you shouldn't trim plugs.


alkizmo

join:2007-06-25
Pierrefonds, QC
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reply to SuperNet9
The socket can probably handle more than 100W.
The 100W limitation is for a light bulb, where there would be a lot of heat generated at the socket.

However that socket could be on 18AWG wire, so don't go too high.
It's about 25W per 50 mini-lights. So with 400 mini-lights, you're looking at 200W. Not so bad for now.

From what I can tell, your mini lights are incandescent. That's why their cord sockets are large/small for polarized power.

However you can't reverse neutral and hot for the LED snowmen.
You risk breaking your LED if you snip prongs to fit in the extension cord from the minilights and reverse hot/neutral.

I'd run a second wire from the light bulb socket with proper hot/neutral for the snow men.


SparkChaser
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said by alkizmo:

However you can't reverse neutral and hot for the LED snowmen.
You risk breaking your LED if you snip prongs to fit in the extension cord from the minilights and reverse hot/neutral.

Why?


shdesigns
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said by SparkChaser:

said by alkizmo:

However you can't reverse neutral and hot for the LED snowmen.
You risk breaking your LED if you snip prongs to fit in the extension cord from the minilights and reverse hot/neutral.

Why?

+2
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alkizmo

join:2007-06-25
Pierrefonds, QC
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reply to shdesigns

Re: Christmas lights power questions..

Well I just know that on the DC side, LEDs can't be reversed in polarity.
»en.wikipedia.org/wiki/Electrical···Polarity

I don't know whether or not the AC/DC ballast can switch the polarity as needed.


tschmidt
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said by alkizmo:

Well I just know that on the DC side, LEDs can't be reversed in polarity.

You are correct LEDs use DC but there is a diode in the string. As far as I know most cheap LED strings only use a half-wave rectifier which is why flicker can be annoying, they are only on half of each 60 Hz cycle.

The problem modifying the plug as bemis See Profile posted is polarization, which is a safety issue. Polarized plugs/receptacles determine which wire is hot and which one neutral. Not a big deal with LED light strings but I would not modify the plug.

/tom

Bob4
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reply to alkizmo
The problem is if the polarized plug feeds a switch and the polarity is reversed, the lamp socket will be 'hot' even when the switch is off. The same goes for a blown fuse; the circuit will continue to be hot. If the snowmen include blowers, reversing the polarity could create a dangerous condition if there is an electrical fault involving the motors.


SparkChaser
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reply to alkizmo
said by alkizmo:

Well I just know that on the DC side, LEDs can't be reversed in polarity.
»en.wikipedia.org/wiki/Electrical···Polarity

I don't know whether or not the AC/DC ballast can switch the polarity as needed.

Since it's AC, the polarity is reversed for you 60 time a sec. The LED lights have to handle that as Tom pointed out. So, to the LED lights there is no correct way (any safety features not included in that statement )

As for modifying a plug, I would not do it. If what you are plugging into is not polarized, then don't use it.
--
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SuperNet9
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reply to SuperNet9
Thanks everyone so far.

The snow men are NOT LED, it's just a normal tiny 7w bulb.
It does have a tiny fuse on the socket plug, so is it still bad that I trimmed it?

Now I also have raindeer heads that are LED, it has a normal Christmas plug at the end, can I take an extension cord and trim that and plug it into the Christmas lights since both ends are the same?

Also I have a tool that tells me what one is the HOT wire, so can't I just make sure I plug it into the hot?( part I trimmed off?)
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tschmidt
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said by SuperNet9:

The snow men are NOT LED, it's just a normal tiny 7w bulb.
It does have a tiny fuse on the socket plug, so is it still bad that I trimmed it?

Yes - the fuse is not going to do anything to eliminate the shock hazard.

A properly polarized screw based socket has neutral wired to the threads and hot to the center contact. This arraignment minimizes shock/electrocution hazard. If bulb is unscrewed while powered and something touches the threads the threads are a zero voltage relative to local ground so there is no shock hazard.

/tom


jack b
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reply to SuperNet9
The "part" you trimmed off is on the neutral blade. As already discussed, it's really not a good idea to defeat the polarity protection. which is a part of the UL listing.

God forbid you have a fire, or somebody gets injured or worse, and the insurance investigator discovers your "modification" to the plug... you can kiss your coverage goodbye.
--
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alkizmo

join:2007-06-25
Pierrefonds, QC
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reply to tschmidt
said by tschmidt:

are only on half of each 60 Hz cycle.

Interesting.
I was considering to install LED strips in my basement for edge lighting. Now you're talking about a flicker and I don't like that.
I'll have to think about this further


tschmidt
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said by alkizmo:

I was considering to install LED strips in my basement for edge lighting. Now you're talking about a flicker and I don't like that.

I assume (know what they say about assume) "real" LED lights use full-wave rectification. If not and flicker is a problem you can always add an external full wave bridge (FWB) to reduce flicker. This causes the LED to be on during both half-cycles rather than just one. This will increase power consumption a little but unless the design is incredibly marginal should not be a problem.

/tom

Bob4
Account deleted

join:2012-07-22
New Jersey
reply to alkizmo
They can use 4 diodes and do a full-wave rectifier, so there will be a lot less flicker.


alkizmo

join:2007-06-25
Pierrefonds, QC
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reply to tschmidt
So basically the LEDs themselves aren't a problem, it's the AC/DC converter that needs to be modified/upgraded to avoid flickering?

That's reassuring. Those 16' (5 meters) strips of LEDs are so cheap. I could light all the basement with LED and dimming capacity for less than 300$.


chamberc
Premium
join:2008-08-05
Irving, TX
reply to alkizmo
said by alkizmo:

The socket can probably handle more than 100W.
The 100W limitation is for a light bulb, where there would be a lot of heat generated at the socket.

However that socket could be on 18AWG wire, so don't go too high.
It's about 25W per 50 mini-lights. So with 400 mini-lights, you're looking at 200W. Not so bad for now.

From what I can tell, your mini lights are incandescent. That's why their cord sockets are large/small for polarized power.

However you can't reverse neutral and hot for the LED snowmen.
You risk breaking your LED if you snip prongs to fit in the extension cord from the minilights and reverse hot/neutral.

I'd run a second wire from the light bulb socket with proper hot/neutral for the snow men.

Most plug adapters are rated for 600w, or at least all mine are. That pretty much means they're safe up to about 1000w.

raythompsontn

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Oliver Springs, TN
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reply to jack b
said by jack b:

God forbid you have a fire, or somebody gets injured or worse, and the insurance investigator discovers your "modification" to the plug... you can kiss your coverage goodbye.

Insurance will not voided because of trimming the plug. That is a myth that when someone modifies wiring in their house and the wiring is not code compliant, the house burns, insurance is denied. Insurance claims are not denied because of something stupid. Insurance claims are denied when the damage is done intentionally to get an insurance claim.


Jack_in_VA
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North, VA
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+1 Absolutely correct


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to raythompsontn
Here in Quebec, it's so strict that it even becomes UNSAFE. You technically can't do more than change a light bulb if you aren't a licensed electrician. What it means is those who want to do some DIY work won't even be able to pay for an inspection, so it will go uninspected.

I think there is a difference between if a fire/damage was caused by unlicensed electrical work that is up to code vs. not up to code.

I can see an insurance company going to court against the home owner if a fire was started, for example, because an extension cord was used as wiring behind a wall.

Now if there was DIY/unlicensed wiring done, but it was up to code, and it caught fire because of a faulty breaker (but proper amperage rating), then that's another story.


tmaertin
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reply to SuperNet9
Click for full size
Clark W Griswold
i think we need to defer to the expert on Christmas lighting...
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Bob4
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join:2012-07-22
New Jersey
reply to SuperNet9
It's not the end of the world. Just make sure the one you trimmed goes into the wide slot.


bbrcat
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reply to SuperNet9
NO,NO ! Bad practice/habit to be messing with...

RogerD

join:2008-07-15
Sunnyvale, CA
reply to SuperNet9
Don't tell my insurance company, but I've gotten around the polarized plugs by using a ground adapter. Everyone I've seen has a polarized socket but not blades.


mackey
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join:2007-08-20
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reply to alkizmo
said by alkizmo:

So basically the LEDs themselves aren't a problem, it's the AC/DC converter that needs to be modified/upgraded to avoid flickering?

That's reassuring. Those 16' (5 meters) strips of LEDs are so cheap. I could light all the basement with LED and dimming capacity for less than 300$.

I've used quite a few of those LED strips, and all of them ran on either 12v or 5v DC. With DC, there is 0 flicker as they never turn "off" like they do with a half or even full (without filtering caps) wave rectifier. That is until you introduce dimming: depending on the quality of the dimmer, you may very well get flicker when dimmed (even if you can't see it a video camera definitely will).

/M


kontos
xyzzy

join:2001-10-04
West Henrietta, NY
reply to Bob4
if he had to trim it, there is no wide slot where he's trying to plig it in.


SuperNet9
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Schaumburg, IL
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reply to SuperNet9
Update: I installed my xmas lights and decided not to put on the snowman that i need to tirm the power end...

Now, whenever I turn on my TV the lights flicker(and only when it 1sts turns on), is that normal?
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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
That must be one massive old CRT TV.