A few weeks ago I mentioned that I was doing my first CCTV install using Ca= t5 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.=20
This is what I learned:
12 cameras in a warehouse. Cameras draw 800ma max. Contrary to what the Bal= un people say their products will do ..... doing the calculations myself,(w= ire size, number of conductors, voltage drop, etc)theycouldn't/wouldn't=20 "guarantee" that the cameras would work at the distances their advertising = said they would. Their estimates of video distance was not my concern but t= hey had no idea that the Baluns could not carry camera "power" over the sam= e 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 outp= ut each channel because there was more than a 10% voltage drop at the furth= est camera if I used 12VDC. $200.00 for power supply. Max safest distance t= o 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 powe= r. 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 elim= iated using Baluns with RJ45 connectors and required more time to untwist, = strip, twist pairs and connect wires to termials, then it would take to cri= mp an RJ45 connector for plugging into a RJ45 Balun. 12 Baluns @ $16.00 eac= h plus shipping. I also had to locate Baluns that had the power and video in/outputs on flyi= ng 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 int= o 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 di= dn't think of this until later) When using Siamese coax, you just have to s= trip 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 c= oax 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 untwiste= d, stripped, twisted in pairs and attached to the screw termials on the Bal= uns. Then, using the hard wire adapter power plugs, it's necessary to run a= dditional wires from the Baluns back to the power supply. But now, since th= e Baluns are located "away" from the back of the DVR, it is necessary to ma= nufacture BNC jumper cables from the video output of the Baluns to run betw= een 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 c= ables from the power supply (mounted next to the plastic junction box.) a g= roup 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 overboa= rd (?) 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 s= iamese wire job.=20
Comments please?