Re: CCTV using Baluns

[Jim <alarminex@xxxxxxx>]

On Friday, January 4, 2013 6:41:58 PM UTC-5, NickMark wrote:
> On Wednesday, January 2, 2013 10:38:37 PM UTC-5, Jim wrote: > I'm startin=
g a CCTV job tomorrow in a small (30K sqft)warehouse using analog cameras o=
ver cat5. Up till now I've used siamese coax and 12vdc. I typically do more=
 residential work than commercial so I usualy don't have to worry about vol=
tage drop. > > > > On this system I'm installing 10 inside cameras all with=
 IR LED's. Each camera draws 700ma with IR LED's on. I've got 5 cameras tha=
t will be in the rear of the warehouse where there are no power outlets so =
the cameras will be aprox 100 to 150 feet from the 24vac power source. I bo=
ught Balun's with screw connections (rather than an RJ45 connector) for the=
 Cat5 so that I could use six of the conductors for the power, giving me ap=
rox a 19 guage wire. I figure that should give me a voltage drop of about 2=
 volts which is less than 10% of 24volts required by the cameras. I didn't =
do any research on what affect the distance of 150 feet over a 24 guage wir=
e would have on the video signal. I don't think it'll be a problem but I ca=
n always switch one of the voltage wires over to the video terminals. > > >=
 > I'm just looking for some comments, suggestions and possible problems th=
at I might not have thought of when using Baluns and Cat5 Any comments abou=
t longer distances using Cat5 would be appreciated also. I've got a couple =
more larger warehouse jobs coming up so voltage drop is going to be a bigge=
r issue I have been using baluns since they came out and actually think you=
 get a better picture on long runs than coax

Hi Nick,

What I'm looking for is how you run the power. I can see that it's convenie=
nt to run the Cat5 wire and less expensive but when you start trying to pul=
l 700ma for cameras over 150 feet of Cat5 wire, there are questions that ar=
ise about voltage drop. When doing a residence, it not convenient to have l=
ittle power packs plugged into outlets or to locate a seperate power supply=
 up in an attic someplace but it's unusual to find a run over 150 feet in a=
 home. However sometimes the same goes for commercial. The small commercial=
 that I'm doing right now doesn't have any electrical outlets in the back o=
f the warehouse but there's 6 cameras back there. I usually use 12VDC camer=
as but I chose 24VAC cameras for this job because of the voltage drop. I co=
uldn't find any of the Balun distributors that were able to tell me how man=
y of the Cat5 pairs were used for voltage and how many of the pairs where u=
sed for video in the Baluns with an RJ45 connector. I needed to know becaus=
e 700ma over 2 pair of 24ga wires at 150 feet is too much of a voltage drop=
 at 12VDC. So I located a Balun that had screw terminal connections instead=
 of the RJ45 for the Cat5 wire so that I could choose to use three pair for=
 voltage and one pair for video.=20

I'll let you know how my theory works out.