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I'm looking to use 24v LEDs (https://smile.amazon.com/dp/B01LYNJTBN/?coliid=I359TOA9WZGE2V&colid=3HRP4V1TLBJ6P&psc=0&ref_=lv_ov_lig_dp_it) along my fence to help light my pool area. I understand from reading online that I'll want to connect power to the strips at both ends to avoid voltage drop. However, details on how to do that for an electrical novice are sparse, and none discuss how to wire a controller into the setup.

I would like to setup a waterproof 21 amp outdoor power supply at the foot of one corner of the fence. I would then like approximately 65' of LEDs to run from there along my fence to the West daisy chained every ~6' (run A). I would also like a 20' run from the PSU North along my privacy fence daisy chained every ~7' (run B). I planned to give each of these runs their own controller.

My guess is that I'll need to get two DC pigtails to run power from the PSU to the controllers. Then I need a very long piece of (10 awg?) wire to run from the end of run A all the way back to the PSU. What I'm unclear on is:

  • Do I connect that wire coming from the end of run A to the same terminals on the PSU that the DC pigtail is connected to or a different set of terminals?
  • Where do I connect the positive and negative of that return wire to?
  • Will the controller act as a switch and continue to properly function when I'm connecting both ends like this?
  • Will connecting run B cause any problem in this setup, assuming it's on its own set of terminals on the PSU?

My alternative is https://www.ysdpowersupply.com/product/factory-price-12v-ip20-68-waterproof-flexible-strip-2835-120d-180d-led-light-stripe/

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  • These don't look waterproof to me. I actually installed some with a transparent plastic pipe around them. Even that wasn't waterproof. They lasted just over a year. Feb 16, 2023 at 9:41
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    Something to consider: There isn't even a hint of an attempt to claim that these have a UL or other safety rating approval. While a 24v DC load is unlikely to cause any significant harm to a person, the power supply (plugged into household current) could. Since you're considering installing these by a pool where there will be wet people any failure of the electronics could be fatal. These don't even claim to meet any particular IP waterproofing standard, they just claim to be "waterproof". i.e., they're both cheap and low quality.
    – FreeMan
    Feb 16, 2023 at 12:36
  • The "alternative" lights do, at least, claim an IP rating for water/dust proof, but still no hint of a UL symbol. They're a step up, but still questionable. Also, the linked site seems to be a wholesaler (or mfgr), not retailer - they list that you can get up to 50,000 meters of light strip per month from them, and go into details about how they package it. Maybe they'll sell you a couple of 3 or 4 meter strips, maybe they'll have a minimum order of 1 kilometer...
    – FreeMan
    Feb 16, 2023 at 12:39
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    OP is likely to purchase an "off-the-boat" PSU, as well, @Agent_L...
    – FreeMan
    Feb 16, 2023 at 12:49
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    @FreeMan Then lead them into looking for a safety rated PSU instead of misleading them into wild goose chase after a rating that can never happen.
    – Agent_L
    Feb 16, 2023 at 12:51

3 Answers 3

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You don't connect strip to the psu. You connect controller to the psu (with 2 wire cable) and strip to the controller (with 4 wire cable for RGB setup).

There are no positive and negative terminals on the strip. There are R,G,B and COMMON (this name may vary) on the strip. They run all the way along the strip - basically 4 wires built into the strip. You can feed the strip from a controller at any point you wish, and tap them off to another strip at any point you wish. The controller doesn't care, as long as you don't hook up too much LEDs to one controller.

If you care about voltage drop, you can double a strip with 4 thicker wires. IMHO it isn't much but a cosmetic defect. You can run the doubling wires all the way, or just some part of it (e.g. first half). I have a 5m, 12V strip and there's no noticeable drop in light level. So at 24V it should be just as unnoticeable over 10m. You have 20m, that still doesn't sound problematic.

There are positive and negative terminals on the PSU-side of controller.

daisy chained every ~6'

Am I understanding it right that you plan to cut and reconnect your strips every 6' ? Damn, that's a lot of cutting and splicing. You're throwing away the biggest advantage of strips. If you can't leave the strips in one piece then just run your 4 wires along and tap every 6' section, this way you save half of strip splicing.

Do I connect that wire coming from the end of run A to the same terminals on the PSU that the DC pigtail is connected to or a different set of terminals?

YOU MUST NOT connect a strip directly to the PSU. Connect R to R, B to B, G to G, COMMON to COMMON.

Where do I connect the positive and negative of that return wire to?

Return cable is 4-wire, you connect it to the controller.

Will the controller act as a switch and continue to properly function when I'm connecting both ends like this?

As long as you're connecting begin of the strip with end of the strip (4 wires). Controller feeds into that wire. You must not bypass the controller.

Will connecting run B cause any problem in this setup, assuming it's on its own set of terminals on the PSU?

As long as the PSU has enough oomph to power both strips and you don't connect anything in strip B to strip A it's ok. You don't need another set of terminals, both controllers can sip same 24V.

Remember that everything after the controller is it's domain. A domain can be straight-shaped or T-shaped or saw-shaped, or loop-shaped, can contain only strips or mix of strips and wires - but one domain must remain 100% sovereign, ruled by one controller alone. Every wire you add can't cross domains.

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  • Is that really a capital, bold YOU MUST NOT? I thought if you connected the strip to your PSU, this is valid, but it's always turned on, and not controllable unless the power passes through the controller.
    – user253751
    Feb 16, 2023 at 16:01
  • @user253751 If you do the no-controller approach then it's a different story. But if there's a controller, and you short it wrong, you'll destroy one channel. The supreme rule is to never cross domains. Crossing RGB to 24V can cost you a controller, but crossing mains to 24V costs lives.
    – Agent_L
    Feb 17, 2023 at 10:53
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I don't see a lumen anywhere in the description, no mention of power or anything of the sort. Buying random LED strips often results in disappointment. I once got some where the reds barely worked, and all the LEDs were the same, probably factory rejects.

I've been using these Miboxer/Milight controllers with success. One remote can control several of these. They're quite convenient. They also have wire terminals that will not melt at the rated current, unlike the one in your amazon link which uses 0.1" headers.

I buy LED strips at this store. They're excellent quality, and the 95 CRI is really 95 CRI.

Here's an example of 24V 10A IP65 power supply from Meanwell. It's a serious brand, IP65 is actually IP65.

Anyway.

The first thing you should think about is LED strip power dissipation. If you want a lot of lights, and you buy powerful strips, above 5W/m, then you have to mount them on aluminium profiles to cool them. Another option is to install them on an existing heat sink, like a metal railing, preferably aluminium. If they're mounted on insulating material like wood or plastic, it's best to not exceed 5W/m, otherwise they'll overheat and die quickly. So you have a choice to make.

LEDs that are made waterproof by slipping them inside a transparent plastic pipe will not be able to evacuate the heat, so power is even more limited.

Then, where will you put them? If they are in direct view below eye level, outside at night, it'll be pretty hard on the eyes. In this case an aluminium profile with a diffuser is a must. If they are above eye level and oriented down it's okay.

Now I'm recommending this controller because you can use several with the same remote and link them. That's very convenient because long runs of 24V cables will drop voltage. Since you plan on 25m of LEDs, with these you can make two independent 12.5m units. If you place the controller and power supply in the middle of each 12.5m run, splitting it in half, now you only have 6.25m of voltage drop on each side to worry about, which should be absolutely fine and not require the hassle of extra wires.

The power supply I'm recommending is IP65 but it comes with wires pre-attached and the ends stripped, and it is not possible to change the wires. This avoids a waterproof cable gland in the power supply, but it means it is designed to be mounted on a wall between two IP65 junction boxes, one for mains and one for 24V where you also put the controller. But you weren't going to use the same junction box for mains and 24V anyway, right?

It's possible to use a non-waterproof power supply and put it in a waterproof box, but these get quite hot, so I'd have serious doubts about cooling.

the controllers are not, so they'd need to be mounted

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Unless the manufacturer or seller says these can be daisy-chained/extended to the length you need, I would assume they can't be and buy a version which does say it has that feature. The power supply might not be able to handle it even if the connector is there.

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  • Eh, this is always good advice if you buy something and don't know how it works (buy the right product instead of hacking it to do what it's not designed for) but we do know how LED strips work by now.
    – user253751
    Feb 16, 2023 at 16:02
  • Not everyone does. If they ask this question, I assume they don't.
    – keshlam
    Feb 16, 2023 at 22:42
  • anyone who answers this question does know.
    – user253751
    Feb 16, 2023 at 22:45
  • Not sure I see your point, then. Answers aren't primarily for the answerers..
    – keshlam
    Feb 16, 2023 at 22:47

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