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Posted By: Tex christmas ligths - 11/14/07 10:52 AM
What should be the average number of connections of a 100 bulb ordinary christmas lights in one convenience outlet?

how about rope lights? how long should it be in one circuit?
Posted By: SteveFehr Re: christmas ligths - 11/14/07 12:29 PM
What wattage are the bulbs? Are you using 120V 15A receptacles? You should never plug more than 1500W worth of anything into a single outlet, but you should be able to safely plug 1500W worth into a single outlet without creating a fire hazard. If they're 100W lights, that's 15 strings. Bear in mind what else is on that string, since loading up a receptacle like that means you can have very little else on any other receptacle fed from that breaker.

Watch your extension cords, too- those cheap thin ones can't take the load of that many lights! Nor can most christmas light timers. You'll have to check the label on your lights, too, for the limit on daisy-chaining them; IIRC, the lights we have include 5A fuses and can handle 6 in-line, but it will vary from light to light.

That said, I metered a string of 100 cheap lights last year and found they only drew about 0.3A a string, which surprised me greatly as I was expecting closer to 1A/string. I'll have to test it again this year when we drag the lights out again.
Posted By: electure Re: christmas ligths - 11/14/07 01:16 PM
Quote
Are you using 120V 15A receptacles? You should never plug more than 1500W worth of anything into a single outlet, but you should be able to safely plug 1500W worth into a single outlet without creating a fire hazard.
.

Huh?

Why 1500 Watts? Why not 1800, why not 1440 Watts?
Is this figure just pulled out of thin air?

(BTW, Tex is listed in his profile as an Electrical Engineer.)



Posted By: HotLine1 Re: christmas ligths - 11/14/07 01:17 PM
Rope light lengths are 'read the mfg. label'. The cheap one are limited to 4 or 5 lengths.
Posted By: Zapped Re: christmas ligths - 11/14/07 02:44 PM
My company does some holiday lighting at some HOAs, and Steve's right, we calculate at 0.3Amps per strand, and the inline fuses vary by manufacturer. You'll find 3A and 5A, and maybe even a few other values. This will define your strand multiplier and overall length.

If you're unsure what your draw-per-strand amperage is, hook 2 or more up, slap on an ammeter, and devide the total amperage by the number of strands to get an average (Amps/# of strands=amps per strand).

Again, as Steve stated, careful with your extension cords and multi-oulet splitters. This is usually where it gets ugly. I don't actually do the holiday lighting installs, but I get to go out and fix it when those guys screw up. I've seen quite a few melted cord-caps.

And please, use GFCI protection. Kids tend to be curious about anything that makes pretty colors.

Good Luck!
Posted By: gfretwell Re: christmas ligths - 11/14/07 03:14 PM
My wife just had a fire inspector tell her they couldn't use any extension cords
shocked
Posted By: Alan Belson Re: christmas ligths - 11/14/07 04:49 PM
Just keep adding stuff till you got more lights than bulbs.
Posted By: SteveFehr Re: christmas ligths - 11/14/07 06:05 PM
electure,

Upon further reflection, I was slipping into talking-to-a-layman mode and using a rule-of-thumb estimate; 15A is not 1500W. You're right: 1440W if they're on for longer than 3 hours, 1800W if they're only on briefly.
Posted By: SP4RX Re: christmas ligths - 11/15/07 04:52 AM
...yeah, but who leaves their christmas lights on briefly?


Shawn.
Posted By: SteveFehr Re: christmas ligths - 11/15/07 05:50 PM
After that shocker of an electric bill a few years ago, I do! It's amazing how much $2 strings of lights can cost if you just plug 'em in and leave 'em on for a month or two...

I invested in a few timers after that.
Posted By: Bolt3 Re: christmas ligths - 11/16/07 06:25 PM
Originally Posted by SP4RX
...yeah, but who leaves their christmas lights on briefly?


Shawn.


My neighbors keep them on all year long cool
Posted By: SteveFehr Re: christmas ligths - 12/05/07 12:42 PM
I put the meter to our lights last night. 5.1A on the tree (11' tree), and another 1.8A on the railing (about 26 linear feet of railing). I tried to get my wife to tell me how many strings she used... her answer? "all of them" lol. Apparently she lost count. I reckon it's about 20 or so.


Will cost roughly $27 to light 18 hours a day for a month.
Posted By: Theelectrikid Re: christmas ligths - 12/05/07 09:23 PM
Originally Posted by Bolt3
My neighbors keep them on all year long cool


People two houses up have them on 24/7/365.

Ian A.
Posted By: drum Re: christmas ligths - 12/05/07 11:37 PM
I put an amp clamp on a couple lines the other night and realized I went a little crazy with the lights this year. The one tree is drawing 12amps by itself.
Posted By: leland Re: christmas ligths - 12/06/07 01:03 AM
Last year just my shrubs, 7.5A
This year about 2A. Coz I can't get the rest of these %%%%%% Strings to light! ARRRRRRRRRGGGGGGGGGGGGGG!!
Posted By: winnie Re: christmas ligths - 12/06/07 01:53 AM
At my old house, we used lights around our porch roof year round. Always felt really welcoming when I would come home at night, but strings would burn out quite frequently.

I bought a bunch of LED strings at the local after Christmas clearance; 75% off and they had lasted at least 2 years (still burning when I moved out).

-Jon
Posted By: TOOL_5150 Re: christmas ligths - 12/06/07 02:33 AM
I lightly toasted a 20A twist lock cord last year. This was one of the 2 cords that ran to the front yard.

[Linked Image from xaetrex.net]


~Matt
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