Re: CCTV with Cat5 and what I've learned.

["E DAWSON" <edawson@xxxxxxxx>]

Hi,

I would recommend a new balun supplier. There are baluns that fit in the
close configuration of the inputs in the back of the dvr, so you would not
need any dongles. I would also recommend that you look to purchase your
baluns directly from the "source"; that will take a lot of your current
costs out of the loop. $16 for each balun is like buying a gallon of milk
for $32... go to the source.

If you strip back each Cat5 so as to allow the one pair to hook up to the
video balun, then you channel the 3 remaining power pairs to your power
supply. You can group the power pairs from 4 or 8 cam wires to go neatly to
the power supply. You can use that flexible split black-plastic tubing to
make it look real neat. It can be purchased in different diameters to
accommodate your design...and it is cheap.

In order to protect the integrity of the video pair to each balun so that
the wire is not stressed in any way, you can also group the outer plastic
housing of the Cat5 from 2 to 4 cam wires by tie wrapping them together with
a stress lead that takes the brunt of any yanking that will surely happen
someday. The leads can be attached to the dvr directly on a housing screw if
needed.

So, the video pair out of the Cat5 outer sleeve is about 3-4 inches long,
and the power wire pairs are as long as you need them; 12, 24, or 36 inches.
There are no additional wires or leads involved or needed. The only
stripping of wiring is at the last half inch of the video pair... do bend it
back in half so that the screw terminal has a bigger bite of contact. Also,
the power pairs, as long as they are properly labeled, also only need to be
stripped at the screw terminals of the power supply.

I agree that coax feels a lot stronger, but there is a reason why the
internet goes thru Cat5 and not coax... cost and efficiency. Did you notice
that each pair in a Cat5 is twisted in a different way? The different twists
allow all those transmissions to least affect each adjoining pair.

Lets say that you have 2 cams somewhat close together, but at a distance
from the dvr. As long as you are within limits, one Cat5 can be run from one
cam to the other, and then to the dvr. Cam #1 can use red for power, and
blue for video. Then cam #2 can use brown for power, and green for video.
Now that should be much less cost for you than having to pay for two
separate siamese coax. At about $65/1000' for Cat5, I don't know how a coax
job could be cheaper. Even more, when the camera is much further and you
need all three pairs for power, it is still much cheaper to only need one
Cat5 per cam.

When you have an extremely long run, depending on the job, there is usually
some kind of electrical feed line in most buildings. Sometimes, it is worth
the cost to figure into the job of having an electrician install a simple
outlet for the power supply. Then you can use only one Cat5 for four
cameras. Just think of how much less copper there will be to buy.

I hope that this has helped you in some way to same money in the future.


"Jim" <alarminex@xxxxxxx> wrote in message
news:253679e7-3b8e-4a5c-a095-6390ed34328c@xxxxxxxxxxxxxxxxxxx
A few weeks ago I mentioned that I was doing my first CCTV install using
Cat5 and Baluns. I think it was here (but maybe in other groups too) that it
was touted as being less expensive to use Cat5 and Baluns compared to Coax
Siamese etc.

This is what I learned:
12 cameras in a warehouse. Cameras draw 800ma max. Contrary to what the
Balun people say their products will do ..... doing the calculations
myself,(wire size, number of conductors, voltage drop,
etc)theycouldn't/wouldn't
"guarantee" that the cameras would work at the distances their advertising
said they would. Their estimates of video distance was not my concern but
they had no idea that the Baluns could not carry camera "power" over the
same distance. Since there are no outlets in the back of the warehouse
(where most of the cameras are located) I had to use 24VAC supply with 1-
amp output each channel because there was more than a 10% voltage drop at
the furthest camera if I used 12VDC. $200.00 for power supply. Max safest
distance to keep cameras at less than 10% voltage drop is somewhere around
150 to 200 feet. In order to do this, I had to inquire with the Balun
mfgs/suppliers, how many of the Cat5 pairs were  used to carry power. No one
that I talked to knew. They "assumed" two pair were used for video and two
pair for power. Two pair for power would not stay within voltage drop spec
at 168feet. (my furthest run) So, I located Baluns with screw terminal
connections, so I could use three Cat 5 pairs for power and one pair for
video. So that elimiated using Baluns with RJ45 connectors and required more
time to untwist, strip, twist pairs and connect wires to termials, then it
would take to crimp an RJ45 connector for plugging into a RJ45 Balun. 12
Baluns @ $16.00 each plus shipping.
I also had to locate Baluns that had the power and video in/outputs on
flying leads, because the Baluns with the BNC connectors attached would not
all fit on the back of a 16 channel DVR if they had to be plugged directly
into the connectors on the back of the DVR. But THEN .... even though you
have flying leads, you also cannot have 12 Baluns hanging off of the back of
a DVR by 6 inch leads. They have to be mounted elsewhere, out of sight. (I
didn't think of this until later) When using Siamese coax, you just have to
strip the power wires back and re-route them to the power supply and connect
them directly to the terminals in the power supply and then continue the
coax runs to the DVR and and crimp BNC's on them. When using the Baluns the
Cat5 has to be run to where the Baluns are going to be located and
untwisted, stripped, twisted in pairs and attached to the screw termials on
the Baluns. Then, using the hard wire adapter power plugs, it's necessary to
run additional wires from the Baluns back to the power supply. But now,
since the Baluns are located "away" from the back of the DVR, it is
necessary to manufacture BNC jumper cables from the video output of the
Baluns to run between the location of the Baluns to the back of the DVR.

Behind the desk, mounted to the wall is a 12 x 12 x 4 inch plastic "juction"
box containing the Baluns $15.00. Out of this box runs a group of power
cables from the power supply (mounted next to the plastic junction box.) a
group of Cat5 cables from the cameras and a group of BNC jumper cables going
to the back of the DVR. BNC connectors 12X2 @ .59each $15.00

I don't know if I'm missing something (?) I don't know if I've gone
overboard (?) but from what I see, with the additional parts and labor
there's no F....ing way it's cheaper to do a Cat5 with Baluns CCTV job
compared to a siamese wire job.

Comments please?