What gauge wire for LED lighting?

[hon30critter]

This is a question for those who know electricity.

I need to buy wire to connect my LED 12 volt layout lighting with the power supplies. Each connection will handle a maximum of 1.6 amps @ 12 volts over a maximum distance of 20 ft. The lighting strips will have a max. of 300 LEDs which are all 3528s. (1.6 amps is what the specs say).

Will 18 ga solid copper wire handle the load properly or do I need something heavier?

Thanks

Dave

[5150WS6]

Personally I think 18 is way overkill.  For only an amp and a half you could run something closer to 26 and still be good.  Check out the gauge/amp table here for more.

http://www.powerstream.com/Wire_Size.htm

It actually says you could get away with 27 but you could always do 26 just to be on the safe side. 

Mike

[richg1998]

No needed.

[mlehman]

richg1998

Our club uses #22 for similar amps. We had a lot of surplus wire om hand.

Rich

 

And that's the thing. Even if the calculation holds up, 26 may easily cost as much or more than plain ol' 22 gauge. And it never hurts to err on the side of a little extra capacity. It'll also be a bit more snag resistant and easier to run being thicker.

[Mark R.]

I've run what seems like miles of ex-telephone wire (cause it was free) under my layout for LED signals and structures. I believe telephone wire is 24 gauge.

Mark.

[peahrens]

I use 22awg black/red stranded auto rip cord, from All Electronics (or Mouser, I forget). Can be ordered to the length you like, was 11 cents per foot IIRC.

[hon30critter]

Mike (5150WS6)

Thanks for the wire chart. I saved it in my 'favourites'.

Mike L, Rich, and Mark R:

Thanks for your quick responses.

 

To everyone, even though 18 ga. is way heavier than I need, I'm going to go with it because I can get it cheap ($51.00 Cdn. for 225 ft - 2 conductor with outer shield).

The 18 ga will also allow me to use crimped ring connectors in the power supplies.

Dave

[5150WS6]

Another way to get cheap wire is old CAT cables that you use for computers or network stuff.  They have 5 or 6 wires in them that work pretty good for hobby stuff.  And out of a 15' CAT cable you can get a LOT of wire.  We always have extra at work that have had the plug or something smashed. 

[hon30critter]

Hi Paul:

I'll have a look at what you suggested before I spend my money. I'm sure I will be able to find it here in Canada. Paying the exchange rate right now is dumb.

Thanks

Dave

[Mark R.]

I'm sorry .... I believe I mis-read your opening post ....

When you say layout lighting, are you referring to the lighting you are using to light your layout / room ? - or the LED lighting for your structures / signals ?

IF you are referring your to room lighting, I take back my post above - that refers to the LED lighting for structures, signals, etc.. For LED light strips used to illuminate your layout / room - I too would go with no lighter than 18 gauge.

Mark.

[hon30critter]

Hi Mark:

Sorry, I could have worded my post better. We are talking about these guys which will be mounted on the ceiling for overall layout lighting:

http://www.ebay.ca/itm/200926217258?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Each strip will be about 16 ft long and will have 300 x 3528 white or blue LEDs. According to the specs. they draw 1.6 amps @ 12 volts max.

Structure and vehicle lighting will be a separate issue.

I thought some of the wire recommendations were a little on the light side.

Dave

[mfm37]

Personally, I would run 18 ga lamp cord or 2 conductor thermostat wire. probably a little heavier then needed but easier to run and keep the job neat.

Martin Myers

[hon30critter]

Hi Martin:

The 18 ga. wire I am looking at is virtually the same as thermostat wire but it has an additional insulation sheath on the outside. The price difference is marginal and I like the idea of the solid wire being easier to keep straight vs the lamp cord. There will be quite a few wires coming off the 'power wall' and I want to keep things neat and tidy. The power wall will have 3 x 12 volt - 18 amp power supplies with 9 circuits each, although not all the circuits in each power supply will be in use.

Thanks for your input.

Dave

[gmpullman]

hon30critter

There will be quite a few wires coming off the 'power wall' and I want to keep things neat and tidy.

Dave,

There's quite a few places on my layout where I have used wire duct or raceway to run multiple wires and keep everything neat (well, at least that was my original goal) 

Here are some examples but you can search for others:

http://www.electriduct.com/Cable-Raceways.html

The stuff I used has snap on covers and some had notches already cut in and other was solid. Sometimes a commercial electrical contractor may have scraps of this stuff they may give you a deal on.

Some of the big-box stores sell stuff for concealing wire on walls for TVs and such that may work, too, but may be too small for the number of wires we model RR types need.

Ed

[hon30critter]

Hey Ed!

I was just looking at exactly what you are talking about.

I have mapped out my plan for the wall where the power supplies will be mounted. It will be on the outside of the layout room walls. There is enough space to allow me to simply staple the wires to the plywood backing sheet.

However, once things go through the wall into the layout room I want to keep them as organized as possible. That's where I was considering the square conduit with the slots in the sides and a removable cap, like this:

http://www.digikey.ca/product-detail/en/3240189/277-5412-ND/2525017

I want to try to keep as much of the wiring as possible right behind the fascia. The track power buss will be mounted separately for obvious reasons, but I'm hoping to keep all the connections for things like the structure and vehicle lighting as close to the aisle as I can. I'm still trying to figure out exactly where the wires need to run.

Thanks.

Dave

[Mark R.]

Dave - Do you actually have those strips in hand ? Curious as to how bright they are. I tried a strip like that and it was no where near bright enough for MY room.

That strip you linked to has the 3528 size LEDs which produce about 7 lumens per LED with a total of 300 leds per 5M. 

I found the 5050 size leds that produce about 12 lumens per led and had 600 leds per 5M lit my benchwork to the point I might seriously consider using them. Each led is almost twice as bright, with twice as many of them !

I also got to try a 5M strip that had a double row of the 5050 size that totalled 1200 leds per 5m .... those were REALLY nice, but kind of pricey as well. Still mulling over that one.

Mark.

[hon30critter]

Hi Mark:

I have the strips on order. I haven't received them yet.

I am very curious to see how much light they produce. I bought 5 of them but if they don't work I'm not out much money. The were a little over $5.00 each with free shipping.

Worst case scenario as I see it is that I will have to buy the brighter LED strips and another power supply. That will still be way less than a decent new locomotive with sound.

Dave

[hon30critter]

Hi Mark:

After you asked the question regarding how bright the 3528 3000K warm white LEDs were I got to wondering if they would indeed be bright enough so I did a little more research. I have determined that they would not be quite bright enough so I have ordered 10 x 5 meter strips of 5630 Natural white LED strips with 60 LEDs per meter.

http://www.ebay.ca/itm/221604259638?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The 'white' is brighter at about 4000 - 4500K vs 3000K for the warm white strips, and the larger LEDs will obviously put out a lot more light. I also have dimmers on order so I can control them as I wish.

I had to order two more power supplies but that was no big deal. I found a really good supplier in California - Mega Watt Power Supplies: 

http://www.12voltpowersupplies.us/

John was really nice to deal with. Of course I haven't had the opportunity to work with the power supplies yet, but at least i know they were made in North America and are not Chinese clones. I hope they are less likely to let the smoke out! That reminds me that I need to put smoke detectors in the train room and in the garage where the train room will be.

Dave

 

[hon30critter]

Now that I have increased the amperage for the 5 meter LED strips from 1.6 amps to 5 amps at 12 volts, what gauge wire should I use to connect them?

Mike 5159WS6 gave me a link to the American Wire Gauge chart but I am confused by whether my wiring would be classified as "chassis wiring" or "power transmission". The two categories have hugely different amperage capabilities. Here's the chart:

http://www.powerstream.com/Wire_Size.htm

Sorry to be so limited in my understanding of electricity.

Dave

[rrinker]

 Use the calculator at the bottom. Maximum amp capacity of the wire is the last thing to worry about. Voltage drop is the concern with long runs. It's all proportional - a wire size that has less voltage drop will also have a greater maximum current capacity. Running wires along the fascia to power LED strips is not chassis wiring. The difference has to do witht he ability to dissipate heat. Inside a closed up box, there's much less air movement compared to a wire in the open air.

 The calculator at the bottom of the page will show the voltage drop for various sizes of wire based on the input voltage and the length. You'll probably want #12 wire to run to an LED strip that draws 5 amps and even heavier wiring, or else locate the power supply closer to the strip, for runs much over 20 feet (one way). That keeps the voltage drop to under half a volt.

 Unlike doing the same calculation for a DCC bus, where you might have the POTENTIAL to put a 5 amp load on the line, these LED strips WILL draw 5 amps, so using 5 amps in the voltage drop calculator makes sense here.

                     --Randy

[hon30critter]

Thanks Randy

I have another question: When I am calculating the length of the run do I include the length of the LED strips themselves or just the hook up wire?

Dave

[hon30critter]

Another question:

Since I will be running 5 amp leads off of the power supply, should I have circuit breakers in each line, and if so, can you recommend which breakers I should be using?

Thanks

Dave

[rrinker]

 Something like this would work:

http://www.ebay.com/itm/5-Amp-Panel-Mount-Push-Button-Circuit-Breaker-for-Boats-Push-to-Reset-Design-/120995129372

They're 12V DC breakers for boats. There are automotive ones too. Some are in the form factor of the blade fuses for cars, which means you would also need some sort of fuse holder or block - there are high current 12V distribution blocks with fuse holders meant for adding lots of heavy duty 12V accessories to a car or truck, you could use one of those panels to break the big power supply into multiple 5 amp circuits.

 Something like this:

http://www.amazon.com/Blue-Sea-Systems-Blade-Block/dp/B000THQ0CQ/ref=pd_sim_200_3?ie=UTF8&dpID=51%2B5nXsWtYL&dpSrc=sims&preST=_AC_UL160_SR123%2C160_&refRID=0TXR93P5DSV6JV3VE8R1

For your wire length, don't add in the LED strip, just the length of wire from the power supply to the terminals on the end of the LED strip.

                --Randy

[Onewolf]

If you haven't purchased your LED strips yet I would suggest you consider 2835SMD strips.  I went through this decision process recently and the 2835 LEDs put out a lot more lumens/watt than the other LED SMD options currently.  I wanted to keep all my layout lighting LED power supplies in a central location which lead to some fairly long runs for the layout lighting LED 12V power bus.  I opted for 12GA bus wire because I have a couple runs that in theory are pulling about 10-12AMPS. 

From my post on another message thread:

---

 

I chose to go with 2835 LEDs vs 5050 vs 3528 vs 5630 because they are significantly more efficient in terms of Lumens/Watt and they have a better heat sink design so they run cooler.  I tested various 5m LED strips and found the 2835 strips use about 1.8 amps at 12V.

SMD2835 have efficiency rating of 130 versus 90 for the SMD5050: https://en.wikipedia.org/wiki/SMD_LED_Module

http://olympianled.com/led-smd-5050-vs-2835-vs-3528/

 

LED SMD 5050 VS 2835 VS 3528

So what do these numbers mean? Is one better than the other? Well, the numbers actually represent the package size.

SMD Type	Dimensions	Watt
SMD5050	5.0mm x 5.0mm	0.24
SMD 2835	2.8mm x 3.5mm	0.15
SMD3528	3.5mm x 2.8mm	0.08

SMD stands for Surface Mount Device. SMD 2835 is the newest SMD configuration and offers the best cost / performance. It is significantly smaller than the SMD5050 and has better heat dissipation.

Advantages of SMD 2835 vs 3528

• Chip direct conduction fins improve the heat dissipation performance allowing it to withstand higher current (40-60mA)
• 2-3 times larger heat sink than 3528, allowing excellent heat dissipation
• Slower light decay of LED chip life
• Oversized light-emitting surface improves the rate of light up to 90%.
• Ultra-thin structure solves the 3528’s long-standing problem.
• 2-3 times higher luminous efficiency than 3528; capable of up to 90-100 Lumens per Watt.
• The costs have been reduced by up to 20% vs the older 3528 design.

[hon30critter]

Hi Onewolf:

Unfortunately, I have just ordered 10 x 5m strips of 5630 natural white LEDs - 60 LEDs/m and two 36 amp x 12v power supplies. Everything is in shipment as we speak. I wish I had known about the 2835 strips before that.

Fortunately, there is always eBay so if I want to go with the 2835s I can always get rid of the other stuff. I already have power supplies that would be suitable for the 2835 strips.

Dave

EDIT:

Can you tell me where you got your 2835 LED strips?

[zstripe]

Dave,

A handy chart to have around......just scroll down to it......:

http://www.powerstream.com/Wire_Size.htm

12 gauge stranded, should be fine.

Take Care! 

Frank

[Mark R.]

I'm going to question this with a logic query ....

Why would it be necessary to use such a heavy gauge wire when the CIRCUIT TRACES themselves carry the full current, and they are considerbly smaller than 12 gauge wire ?

Not that I'm saying anything like 22 gauge wire would be recommended, but 12 gauge sounds a bit like overkill.

Haven't we gone over this in another thread ? ....

Mark.

[ricktrains4824]

According to handy chart referenced in above post, go no smaller than 14AWG for those 5 amps, so, based on that, 12AWG is not that far off.

With 10 strips, per other thread, I would totally recommend "overkill", if only for safety reasons. 50 amps is quite a bit of power to be messing around with. Hope those strips all get their own supply line. If they don't, even 12AWG is not enough, per referenced chart. If it is all one line, then now we are talking 3-4AWG instead.... So, I only hope those 10 are broken up.

[carl425]

zstripe

A handy chart to have around......just scroll down to it......: http://www.powerstream.com/Wire_Size.htm

Can one of you electrical guys explain this chart to me?  They want 14ga wire for 5 amps, but house wiring spec is 14ga for 15 amps and 12ga for 20 amps.  Why the difference?

Also, for the OP's question, isn't the length of the wire important?

[Mark R.]

Can someone explain how the paper-thin circuit traces can carry 5 amps the length of the 16 foot strip, yet you have to connect it with 16 feet (for example) of wire 20 times plus that size to the power supply ?

Mark.