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



"G. Morgan" <sealteam6@xxxxxxxxxxxxxxxxx> wrote in message
news:kmulf8thq0ui17fkdlkmltm4c13oee9crp@xxxxxxxxxxxxxxxxxxxx
> Jim Wrote:
>
>>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?
>
> In a warehouse environment with the large lengths of cable I can see why
> you might be saying that it's not cost effective.  If it were a 12 cam
> job with drop tile in a retail store (or home) it's definitely faster
> and cheaper with baluns.  Think about this, you can use a flex bit to
> corner mount a camera just like a motion because the cable is so thin.
> All your wire running tricks from security come back into play with CAT5
> video.  Try using a 3/8" flex bit to run siamese cable!
>
> As others have said, in the warehouse some guys will place the power
> supplies mid-run (wherever an outlet is convenient).  You can strip back
> the outer jacket and inject power before it goes out to no-man's land.
> Makes it a pain to troubleshoot if you don't document where the power
> supplies are though.  Since *you* are likely the one to service it, you
> may not need that level of documentation a big company has where a
> different tech may go out each time.
>
> I think you'll find baluns cheaper than $16/pair will do the job just
> fine.  ADI sells them in a bag with two for half that.  Also, if you
> plan for always using CAT5 in the future you may want to change the cams
> you buy.  Some have built-in baluns.  You can pre-build the head-end box
> at the shop to make the on site part go faster.  I have not found the
> perfect way to mount baluns in the box yet, but with some trial & error
> and all the clips and stand-offs available I'm sure you can make a
> system that works for you.  MCM Electronics has TONS of stuff like that.
> The catalog is 2" thick.  And it's full of goodies for our trade -
> including audio.
>
> Anyway, how was the video quality?  Any noticeable difference?
>
> <aside>   I bought a Raspberry Pi mini-computer for $35 from MCM.  It
> runs Debian Linux on a SD card.  It has 15 I/O's and the possibilities
> are endless.  Comes with 512M RAM and a HDMI & composite out, plus audio
> and network. If you like to tinker, get one!
>
> <aside 2> Someone asked where to get LCD screens about 6 months ago, MCM
> has them in all sizes.
>
>
> http://www.mcmelectronics.com/
>

What I meant by buying video balums at $16/pair is like buying milk at
$32/gallon is this: milk costs about $4/gallon on average, so if you do the
ratio, balums should not cost you more than ???$/pair?

...ADI is not a source, they are at least 3 tiers away from being the
source.
Much profit is derived by companies who have effectively 'taught' their
customers what they should be paying for an item.









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