1 wire size don't fit all

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Revo2Maxx
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1 wire size don't fit all

Post by Revo2Maxx »

So almost 2 years ago I helped a friend of mine install his cameras. One of them had to be just under 300 feet away and the main reason I helped him was because when he put 2 cables together that was 150 each he couldn't understand why it wouldn't work. So I packed up my last 400' of RG59 with 18awg Siamese cable and my backup power unit, went to help him install some cameras. Why this is important laying down the what worked at the time and why it don't work today... So looking back at things it was 278' of cable just under 300 and I almost ran out 300 just to make sure there was enough for future if needed but didn't.. Also ran 2 other runs because again the cameras to his cables didn't work.

Well sadly almost 2 years later I get a call and he said something must be wrong with the cable I gave him because he installed a new camera and came on for a second didn't get though the power up portion and went offline. (rather then testing out camera he said it was bad cable) So I think ok maybe when he pulled the power plug or something he damaged the power plug only thing I could think. I get there an no wonder it don't work he is trying to use 278' of cable to power a camera that draws 2 amps. When he tested it on the house at the recorder it worked because the 20' of cable I left for testing was good enough to power 2amp camera..

So First thing I do is look at the camera and the Specs say 12v 2amp and Right off I said that is the issue 2amps 278 feet away will never work on 18awg wire.. Asked him if he had hooked the old camera back up to make sure it was not the line. He was like no thought it was bad.. So while I don't think others should do this I did and used a Water seal unit however there is an outlet in his Tack room the cable runs pass the room under ground 6 feet away. So I dug up the cable 20 foot section and cut the 18awg wire to give me enough to get into the room. Using the other power he had for the unit to start with back at the DVR we moved the PDU that I took him to the Tack room.. Now the cameras power is only 35 to 40 foot away and 13.6v at that distance I showed him it was still over 12.5v at the camera and it is working as expected.

Main issue is that his new camera has 5-50mm Motorized zoom lens, heater and IR and when he first plugged it in the first test is only running the lens to home position, then test the IR and Heater and by the time it got to setting the lens the camera was taking to much current for the power to be able to flow almost 300 feet. It would have needed 12awg to go from the house to the camera and even then I am not sure it would have been able to push enough current on a 3amp fuse at it's high power setting.. Now with the PDU in the Tack room and the camera within 35 to 40 foot of the power the camera works well and he is able to control the zoom lens over UTC. After turning it on the camera power was at 13.32v and after a minute and I am guessing when the Heater kicks in because the power did drop to 12.865v and turning the IR's on 100% the power dropped to 12.54 to 12.6v.. When I got there and I connected to the camera I tested the power when he had it running from the house and the camera power was showing 9.32v for around 30 seconds and that is camera testing lens as soon as that is done the volts dropped to 7.329 and that wasn't even enough volts to transmit the video to the recorder..

Funny thing is I remember telling him 2 years ago when he was setting up his cameras that his cable couldn't power the camera at the distance because the cables use cheap small gauge wire and as far as his camera is from the house only reason that camera and cable I brought could work was because the current draw for the first camera used was only 250ma and under 350ma max and had it been over 500ma or around 500ma I am sure the camera would have been ok but it was 2 amps and that is just way to much.. Did some testing and the camera when it turns on draws 1.2amps to test lens and even in that time there is no video to the recorder it isn't until after the test that the current drops down to 967ma and it kicks on the Video then within a few seconds it ramps up to 1.65 amps After heat and IR test it goes back to just under 1 amp constant current. Yeah I am getting to old for this lol.. I will tell my friends what to buy and use let them work it out. It is to could out there for me to mess with my own Camera hardware and only helped him because that is what friends do. However really because I didn't want to spend a month or 2 wondering if something was really wrong with the wiring I installed.

By the way Snow on the ground had he not had a Back hoe for getting past the frost line I was not digging nothing for no one.. However with his tractor doing the hard work hand digging to the cable from there was cake. Cleared the snow off the ground over the dig area 10 wide from tack to camera location then using a 24in bucket to take off the top to where the Caution tape was. Sand down to the cable from there. We didn't even damage the toning cable just moved it out of the way, layed more from there to the Tack room and more caution tape after filling back in sand left the rest for him to fill back in
Try to Avoid CCA Networking Cables They are JUNK PERIOD!
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James
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Re: 1 wire size don't fit all

Post by PromptCritical »

I'm an electrical engineer, but I'm lazy and like to use the Blue Sea Systems circuit wizard.

http://circuitwizard.bluesea.com

It's a bit nicer than your average wire lookup table because it also figures in voltage drops over a distance based on load. For instance, I just ran 12V, 2A, 300 ft. If you can afford a 10% drop, you need 12 AWG, which normal tables will say is good for 30A. Surprised me a bit, even.
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Revo2Maxx
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Re: 1 wire size don't fit all

Post by Revo2Maxx »

Interesting, I am not sure how many people would know how to use a program like that or any other Circuit Wizard. Interesting that a program designed for circuits would talk about Volts over Distance of 300 feet.

Sadly I am not sure that Voltage Drop is going to do much for anyone. As from what I know while I did say 12awg was needed that is because the camera can work at 9v however even at 12 awg wire True Copper wire not this JUNK that is going around CCA. 12v 2 amps 300 feet is over 15% drop.. While the PDU was set to produce 13.6 even that at 300' in 12awg is over 13% drop but still above the camera voltage drive ability so it would work. How well or how long that is a different story..

Sadly 12awg for 120v power over 300' isn't going to work either and that is just Ohms Law.. 15amps to run 300' would need #4 wire Copper... and normally 12awg is for 20 amp and for 20amp to run 300' one should use #3. But that again is outside of the scope of the topic..

My reason for making the topic was so others that might have a Camera they are looking to run a long distance might want to consider having power closer to the cameras location (or use a low current camera) and/or have some type of guide of understanding why it might not have worked.. Sadly there are many different types of cameras and some built different then others, Some might not work under 11vdc where some might work down to 7..
Try to Avoid CCA Networking Cables They are JUNK PERIOD!
Where there is Life there is Hope
James
PromptCritical
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Joined: Mon Jan 25, 2021 1:52 pm

Re: 1 wire size don't fit all

Post by PromptCritical »

Well, the 120V over a distance isn't awful, depending on your load.

If you actually are drawing 15A, then you will get significant drop. However, two things are at play here: Actual current draw of what you're feeding, and modern power supplies. If you're just running a camera, you're looking at maybe 15W. At 120V, that's like an eighth of an amp. You will get almost no voltage drop at all. Conversely, most modern electronics use switch-mode power supplies, which have a very wide range. For instance the phone charger I have next to me operates on 100-240V. It will work just fine even if I have a 15% drop on the line.

Short version is that wire can be matched to the application load if that won't cause problems later. 12awg is probably sufficient for most CCTV stuff out to 300', but 10awg would be better.

Here's another calculator: https://www.southwire.com/calculator-vdrop According to this, 120V on 10awg wire for 300 ft allows for 5A at less than 3% drop. That's over 500W available at the end. Shoud be enough to run several cameras, lights, etc.
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