problems with cat5e

[dannyIRL 0]

My 3 recent installs, distances of 10mtrs to 70mtrs, have gone horribly wrong. I used Cat5E for the 1st time and probably last! I could not get the power up. When i put power directly to the camera and used the cat5e for the video signal it worked fine. It happened on about 11 out of 16 cameras. I re-ran some of the cable and some of them just seemed to fix themselves. Really strange. I have a big job next week & I don't know should I risk the cat5 or go with the RG59?

[thewireguys 3]

Do you have a Cat5 tester? Did you use quality cable? Cat5 cable is very fragile and needs to be pulled properly or you can break pairs in the wire.

[craiga 0]

Hi.

A basic issue with cat5e is the voltage drop on the 24 awg wires. To compound this a lot of cheap baluns use 1 pair for power and 1 pair for video and the other 2 pair in the cat5e are left unused. Using 3 pair for power reduces the voltage drop considerably. This calculator will let you calculate the voltage drop for the number of pairs, length of cable, and power requirements of the camera you are using (note it says input around voltage and current (amps)), but what you should enter are the minimum voltage and maximum power requirements of the camera:

http://www.netkrom.com/voltage_loss_over_cat5_calculator.html

 

Many cameras allow a range of input voltages (e.g. 12-24VDC). If you use an 18 or 24VDC power supply for such cameras, then the voltage drop is unlikely to be an issue. If you use a 12VDC power supply in this instance then you will almost certainly have problems: some cameras still function, some with function with lots of video problems, some will work as long as the IR lighting doesn't come on, some won't function at all when the voltage isn't high enough (but it's never a good idea).

 

You can measure the voltage at the camera end with a simple voltmeter but do this with the camera attached, otherwise you'll see no voltage drop at all.

-Craig

[cglaeser 0]

My 3 recent installs, distances of 10mtrs to 70mtrs, have gone horribly wrong.

 

Several important questions:

 

1. Did you purchase cables with connectors or use bulk cable and cut to length?

 

2. Did you use RJ45 connectors or strip the wire and use screw terminals?

 

3. Did you use PoE? If not, what voltage did you use?

 

Best,

Christopher

[rory 0]

What cameras were they? I know from experience you cant run EX82 cameras (Extreme CCTV/Bosch) power over Cat5, at least not at 50'+, but those are dual cameras with powerful IR and an extreme current draw.

[Sawbones 0]

Are you using 12V DC? Try using 24V AC instead of 12V DC, and see if that doesn't fix it.

 

There's a reason why we use AC current in the United States (aside from Nikola Tesla ultimately winning his famous battle with Thomas Edison). AC carries much better over a distance than DC.

[cglaeser 0]

There's a reason why we use AC current in the United States (aside from Nikola Tesla ultimately winning his famous battle with Thomas Edison). AC carries much better over a distance than DC.

 

Not true for long distances. For long-distance distribution, HVDC systems are less expensive and suffer lower electrical losses than AC. AC is easier to step up and step down.

 

Best,

Christopher

[Sawbones 0]

There's a reason why we use AC current in the United States (aside from Nikola Tesla ultimately winning his famous battle with Thomas Edison). AC carries much better over a distance than DC.

 

Not true for long distances. For long-distance distribution, HVDC systems are less expensive and suffer lower electrical losses than AC. AC is easier to step up and step down.

 

Best,

Christopher

 

I know it's used somewhat in Europe and Russia... but for the purposes of the OP's question, I think he might have better luck with AC, since we're not using voltages anywhere near what you're talking about.

[cglaeser 0]

I know it's used somewhat in Europe and Russia... but for the purposes of the OP's question, I think he might have better luck with AC, since we're not using voltages anywhere near what you're talking about.

 

Agreed, long distance transmission has nothing to do with the OPs question, but you tossed in a common misconception regarding the Tesla vs Edison debate, and I wanted to correct the record.

 

Regarding the OPs question, increasing the voltage could help because that decreases the current for the same power, and 24VAC is a reasonable suggestion. However, I would still like to know the answers to the questions I posted before making any recommendations. For example, I'd like to know more about the connections (e.g. RJ45 or screw terminals).

 

Best,

Christopher

[dannyIRL 0]

I know it's used somewhat in Europe and Russia... but for the purposes of the OP's question, I think he might have better luck with AC, since we're not using voltages anywhere near what you're talking about.

 

Agreed, long distance transmission has nothing to do with the OPs question, but you tossed in a common misconception regarding the Tesla vs Edison debate, and I wanted to correct the record.

 

Regarding the OPs question, increasing the voltage could help because that decreases the current for the same power, and 24VAC is a reasonable suggestion. However, I would still like to know the answers to the questions I posted before making any recommendations. For example, I'd like to know more about the connections (e.g. RJ45 or screw terminals).

 

Best,

Christopher

 

It was bulk cable cut to length from my normal supplier. All the runs were in duct so no chance of damage to cable.

I used baluns on each end.

DC power supply.

The cameras were from ICRealtime.

 

I think the problem may be the dc/ac supply.

Sound for all the replies.

 

Rgrds,

Dan

[cglaeser 0]

It was bulk cable cut to length from my normal supplier. All the runs were in duct so no chance of damage to cable.

 

Cat5 is fragile, but the breakage is usually at the termination, not the cable itself. That is why many alarm installers would never use Cat5 for alarms. If you used RJ45 connectors and you tested all the paths, you should be fine.

 

I think the problem may be the dc/ac supply.

 

What is the voltage/power specs of the camera?

 

Did you test the voltage at the camera?

 

Best,

Christopher

[tomcctv 190]

My 3 recent installs, distances of 10mtrs to 70mtrs, have gone horribly wrong. I used Cat5E for the 1st time and probably last! I could not get the power up. When i put power directly to the camera and used the cat5e for the video signal it worked fine. It happened on about 11 out of 16 cameras. I re-ran some of the cable and some of them just seemed to fix themselves. Really strange. I have a big job next week & I don't know should I risk the cat5 or go with the RG59?

 

for the distance you are doing i would use RG59 with power. cat5 can give many problems if not used right. the main faults i find with other installers problems are they have stripped the cable to much at each end leaving long tails or they have un twisted the cable at the end. (keep the twist right up to the balun)

[rory 0]

for the distance you are doing i would use RG59 with power. cat5 can give many problems if not used right. the main faults i find with other installers problems are they have stripped the cable to much at each end leaving long tails or they have un twisted the cable at the end. (keep the twist right up to the balun)

 

or he can even just run 18awg wire for the power, like lamp cord wire which is cheap.

[tomcctv 190]

for the distance you are doing i would use RG59 with power. cat5 can give many problems if not used right. the main faults i find with other installers problems are they have stripped the cable to much at each end leaving long tails or they have un twisted the cable at the end. (keep the twist right up to the balun)

 

or he can even just run 18awg wire for the power, like lamp cord wire which is cheap.

 

Hi Rory just out of interest what is the price you pay for RG59 were you are for say 100m also cat5 300m

[rory 0]

Hi Rory just out of interest what is the price you pay for RG59 were you are for say 100m also cat5 300m

I just checked a local electrical store the other day, first time ive found one here that sells RG59 Siamese (they dont sell RG59 itself), and they want 40 cents a foot. Use to have to bring it in and it would end up around $500 for a 1000' roll after shipping and Customs Duty.

 

Cat5 no idea, other then short pieces I havent had to buy any boxes in years, I leave that to the electrician and they bill seperately, but the short pieces can be $25 for just 15'. RG59 is more common here for CCTV, in addition to the fact that we would have to order any baluns we need and if they come bad or suck it takes weeks to get some more, as nobody sells them here. But, I can get BNCs from a number of places here. And ofcourse BNCs are cheaper.

 

Sorry I dont know what that all is in metres.

[Sawbones 0]

There are a few online calculators for line loss based on length of run and gauge of the wire. It can be significant.

 

Here's one such calculator:

 

http://www.powerstream.com/Wire_Size.htm