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Discussion Starter · #1 ·
Hello,

I want to run 8 CCTV cameras and 8 motion LED lights from one 12V 20A power supply. My cameras are rated as 500ma and the lights are 850ma. I will have eight wires coming off the power supply. Each wire will be running one camera and one light. I am using a Y splitter to split the power to the camera and LED light.

So how many amps would be going through my Y splitter? They are rated for 2 amps. I assume the devices only draw the minimum they need, so 1.35 (500ma + 850ma) total amps are traveling through my splitter to the devices even though my power supply is 20 amps. Is that correct? Am I safe to use Y splitters rated for only 2 amps with a 20 amp power supply as long as the devices connected directly to the Y splitter are under 2 amps total?

Thanks
 

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A milliamp is 1/1000 of an amp. So 500ma is .5 amp, 850milliamp is .85 amps.

What is a "Y splitter"?

How long are your runs? You may in encounter voltage drop so your device(s) may draw slightly more amps then what is on the nameplate.

Cheers
John
 

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Discussion Starter · #3 ·
A Y splitter attaches to the end of the cable to split it so it can deliver power to two devices. See image.

Seven of the cables are 50ft and one cable is 100ft. About how much drop should I expect with those lengths? Thanks!

 

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Does your power supply have 8 separate outputs and the splitters are used at the far end to split to each camera and LED? Or are you stacking the splitters at the power supply, so that only one is connected to the power supply and that one splitter connects to two others, which in turn connect to more splitters? The concern is that the first splitter will be handling the current load for ALL the cameras and LEDs.

Also, a 12V power supply with a 20A output is not Class 2, and you will need to use proper wiring/protection methods according to the NEC.
 

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Discussion Starter · #6 ·
Does your power supply have 8 separate outputs and the splitters are used at the far end to split to each camera and LED? Or are you stacking the splitters at the power supply, so that only one is connected to the power supply and that one splitter connects to two others, which in turn connect to more splitters? The concern is that the first splitter will be handling the current load for ALL the cameras and LEDs.

Also, a 12V power supply with a 20A output is not Class 2, and you will need to use proper wiring/protection methods according to the NEC.
The power supply would have 8 separate outputs. See image for type I am using. I've never used this type before but it seems fairly straight forward. The splitters would be on the far end.

 

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Discussion Starter · #7 ·
If you use a standard voltage drop calculator, you would need a #12 AWG to have .85 amps at 100 feet with a 2.5% voltage drop.

If you need the 1.35 amps at 100 feet you are up to a #10 AWG wire with a 2.4% voltage drop.


Edit: your current requirements is slightly off this chart https://www.2mcctv.com/blog/2011_06_09-voltage-amperage-guide-for-your-cctv-cameras/

Cheers
John
Thanks for the info. I am not sure of the gauge and do not see it listed on the wire or the website I purchased it from. It is made for 12v CCTV so I'm sure the gauge should be appropriate for the length. However they are intended only for CCTV, I'm adding the LEDs myself and figured using a Y splitter would be much easier and cheaper than running 16 wires, one for each camera and one for each LED. Of course if it's dangerous then I can spend more on running additional wire. That's what I'm here trying to figure out. Thanks again.
 

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The power supply would have 8 separate outputs. See image for type I am using. I've never used this type before but it seems fairly straight forward. The splitters would be on the far end.
Ok, I understand.

Still have some concerns about that particular power supply.

It doesn't appear to be UL listed, or certified by any nationally recognized testing lab.

Although the outputs are fused and PTC protected, technically, it is still not considered a Class 2 power supply, since it is not specifically labeled as such.

Each output is fused at 1A according to the specs. You need 1.35A for each camera/LED pair. You're gonna blow a lot of fuses!


Reading 1-star reviews on Amazon, I would stay away from this power supply (and this company).
 

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Are you using an 8 channel power supply or an 18 channel? Your image shows an 18 channel, 20 Amp, but you keep referring to an 8 channel 20 Amp, which I don't see listed on the website.

If it's 18, then just run a second 18/2 or 16/2, depending on length, CL2 rated cable for the LED motion light. It will keep you from blowing fuses and will have redundancy, if one or the other goes bad or overcurrents, you wont lose both the camera and light.

Also keep in mind the 18ch power supply has a fan in it, which can be bothersome to some people. It runs pretty much all the time, so consider where you'll be mounting that as well.
 
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