CCTV Power Supply Distance, Cat5 & Siamese Cable Considerations 21

Cat5 or Siamese Coax

I have experienced a number of clients that ask about using cat5e cable rather than traditional Siamese coax cable for their camera runs.  Is cat5 heavy enough?  Will I be able to transmit video as far as I can with Siamese?  How does the power work with regards to cat5 cabling?  These are all very good questions and we will look at each in turn.

-First, Is cat5 heavy enough? and similarly, will I be able to transmit video as far as I can with Siamese?

The short answer is yes, cat5 is heavy enough to transmit video.  In fact, most sources show that the 24AWG (American Wire Gauge) used to make up the cat5 will actually transmit video farther than the RG59 used in the Siamese cable.  One only needs to incorporate an adapter from cctv BNC connectors to unshielded twisted pair (UTP) to make this physical connection work.  Such an adapter in the CCTV business is referred to as a balun, and comes in several different models – Learn more about Baluns and BNC connectors.

-Next, How does the power work with regards to cat5 cabling?

This is the part that needs special attention.  When using cat5 for power transmission, I always recommend using 24VAC or dual voltage cameras, in order to not starve or under-power the cameras.  This is done by incorporating two (2) of the twisted pairs in the cat5.  So essentially, you will have one (1) of the twisted pair being used for video and two (2) of the other twisted pairs used for the power, leaving you with one (1) unused twisted pair in the cat5. (I have seen all-in-one adapters that allow DIY installers to plug in a finished cat5 (RJ-45) connection on both ends and accomplish both video and power portions, though distance is usually a limiting factor.)

So if you or your clients have some extra cat5 lying around, go ahead and give it a try.  It wasn’t mentioned earlier, but even your back will thank you, as cat5 is considerably easier to carry around and pull through conduit!

Wire Gauge and Voltage Drop

For the majority of analog cameras, Siamese cable is adequate to run both the power and the video.  The most common type of CCTV Siamese cable is a combination of RG59 coax and 18/2 power cable.  RG59 will carry the video signal around 750 ft, so for most runs that will be more than enough.  Power is what will restrict most longer runs.

18/2 cable is two 18 gauge wires.  That is simple enough; if there were four wires it would be called 18/4.  Like shotgun shells and needles, wire thickness is measured by gauge and the smaller the gauge the thicker the wire.  So, 14 gauge wire will be thicker than 18 or 24 gauge wire. The reason that is important is that a thicker wire will transmit electricity farther that a thinner wire.  Why does this matter?  Because if you have a long run from the power supply and DVR to a camera and there is no way to power the camera locally, you will have to adjust the gauge of the wire to compensate for the voltage drop – View our voltage/amperage quick guide.

Below we’ve created a chart that will help with planning a long run.  Make sure when calculating that you know the voltage and amperage used by the camera.  Make sure you use the max amps listed on the spec sheet (here’s an example where we talk about amps and power along with other important features to look for on a spec sheet).

If you have a question or comment about CCTV power supplies or cables, we welcome comments below!

Max Power Distance Chart

(Quick chart based on a 10% voltage drop from power source to device)

Click to Enlarge Cable Distance Chart

CCTV Power Distance Chart
Maximum Cable Distance from Power Source

Click to Enlarge Cable Distance Chart

Embed the Max Power Cable Distance Chart on your site

2M CCTV Blog


  1. Nice article(s). Should have been reading your site earlier!

    About running cat5e wires, if i need bout 150 cameras, do you suggest:

    1)run 150 pieces of cat5e? and another separate wiring for power?


    2)run less than 150 pieces of cat5e and use two pairs for every 2 cameras and the remaining 2 pairs for power?

  2. Hi,

    I need to install 180 cameras in a departmental store consist of 4 floors, which has security room on top floor…each floor is around 2500 sqm..
    Need your advice or suggestion for cabling stuff plz…
    what you say about central power supply adaptor?


  3. I am installing ethernet and cctv in my folks home that they are building. I am running 23AWG Cat6 for data and voice, I know it’s not needed but I love future proofing. Anyways, I’m going back and forth on which to use for CCTV, Cat6 or Siamese. I’m installing 4-6 cameras around the home and 1 or 2 approx 500-750 ft away at the gate. I’d like to stick with CAT6 since it could be used for other purposes in the future, but I am more concerened with doing what will work best. I’m pretty confident on how to deal with the close cameras, but Im concerned about the distant ones. Any suggestions and specifics would be GREATLY appreciated.

  4. Hello I’m going to run 4 cams about 1000 to 1200 ft from head end
    I have 18/2 but thinking 16/2 would would prob work better or do I need
    14/2 for distance? Also is there a cable avl w 2 coax and 4 power leads
    In same jacket?
    Thanks Greg

  5. Want to install 15 cameras in an estate do i run 15 cat5 cables or what do i do?

  6. Thanks friends. Can you help with this? Got this installation to do. The camera positions are at different far distances apart. So I choose IP cameras and create a group network for cameras that are close to each other. Then I intend to transmit the data/video to the main viewing centre from each separate group with wireless point to multi-point radios. I decided to use IP cameras because I think analogue won‘t do well with long distances. The cameras have 12vdc. Can I use part of the the cat5 twisted pairs for power? Or do I run separate cat5 cable for power? Or should I use a power cable instead of cat5 cable for power? Which do you think will have better performance for long distances to viewing centre – IP or Analogue cameras. Advise me please.

  7. I have 16 cameras to install on a street which is divided in 4 sections (4 cameras each section). Each section measures 150 meters from the DVR and Power Supply.
    I am planning to use 18 port power supply with 18 12 Amp, 12V DC Output and a RG59 Coaxial Siamese Cable 20AWG, 18/2 AWG.
    Each camera has Power Specs of (12V DC, <2W LED OFF/6W LED ON).

    Did I made the right decision in choosing the right Power Supply and Transmission Cables?

    Please Reply. Thanks!

    Jorge Resley
  8. I plan on putting cctv cameras in our subdivision gate which have access to power, but I plan the monitor to be located in the central security office which is approximately 0.4miles or 2112 FEET, can I use CAT5 cables for video going to the DVR and use the ready made cables from amazon for power which I can get from the front gate? thank you, your blogs are very informative and uses layman terms

  9. Hi everyone

    have a nice day to all
    im going to run 16 HD-SDI CCTV cameras for about 300 meters with full coper coaxial RG11 each camera distance im running 12VDC power for each HD Camera,i try all what i have in my knowledge ,but useless,but unfortunate cant success So please tell me do i run a cat5 cable or RG11 or what do i do?
    what would be the best system for the distance???? kindly please let me know if some one experience this type of issue,any suggestions and specifics would be GREATLY appreciated.

    syed azam alhasni
  10. It is a good thing to know that cat 5/5E or cat 6 can not hang by its own weight in the air nor can it stand any stretching whatsoever. If you run twisted pair wiring in a bind (even a slight bind) you can wind up with ghosting and other noise.

  11. your installing 180 cameras and you don’t know what wires to use…… well from experience id use cat5e for video and power under 250ft… so you can get 2 cameras per line… however if the runs are farther than 250 ft then I would run cat 5e for video only and 18/2 for power… and if the power is only being supplied from the 4th floor then you will should be fine but if you have access to place a power panel on each floor I would run the power for the cameras on each floor to reduce labor!

  12. Using coaxial cable for an HD-SDI camera you can run a max of 150 feet ~ 45 meters. You need multiple coax extenders to be able to reach that long of a run.

  13. use fiber optic cable with audio video to ofc converters its the best mode of sending video in high quality

    prakash bengani
  14. Hi,

    We have to use ip cameras for outdoor purpose through the fiber cable .So i need two power supply unit for those cameras(One for Converter,One for Blower motor of camera) . What is the maximum distance should i keep from camera to the power source ? Can i keep power supplies inside the building / Is it safe if i keep power socket nearer to the camera ? What kind of power supplies should i use ?

  15. awg is american wire guage

  16. I wanted to know if RG59 siamese cable would be good to run a 12v bullet camera w/ IR a little over 200ft. I’ve been reading and I’m seeing a lot of people say that the 18/2 wire that comes with the RG59 siamese cable that it’s only good for about a distance 150’ft. For power. Most of my cameras might just come under 150’ft but 2 might be a little over 150’ft. It will most likely be close to 200ft and I just want to know what I should run for power for cameras at about 200’ft. Thanks in advance.

  17. Distance from my camera to dvr is 150 feet can u suggest me the best wire for transmitting video signal

  18. I have a problem with 32 pcs HD CVI Dahua Cameras, with 16 Ch 2 pcs DVR and 20 Amp 2 pcs Power Supply. Wiring done by D-Link CAT6 cables, earthing tested and found Okay. Picture has lines in it. No High Voltage Electric Cables are running parallel to CCTV cables, even I checked with Video Baluns but still there are lines. Crystal Clear picture is coming only in 3+1 Cable.. Wiring is conceal so cannot change it.. Can anyone please solve it??

    Subhasis Sarkar
  19. 3+1 Cable or RG6 Cable will be best for you..

    Subhasis Sarkar
  20. iam installing cctv IP camera for about 1000 meters long distance from the nvr and im just using utp cable to wire it, can i use switch hub for every 100 meters long? so that the connection will stay firmly until i reach 1000 meters long. thank you and God bless.

  21. One of our reps will be contacting you soon. Thank you for your business.

    Sylvia Gendron

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