Can someone please explain how BALUNS work and how to instal

[johnny916 0]

I've noticed people using the term baluns, I usually just install the cameras with the wires that came with the customers system.

 

How do Baluns work? What cable is used with them? How do you install a Balun on a cable? Do you always use them for most CCTV installations now?

[Soundy 1]

I've noticed people using the term baluns, I usually just install the cameras with the wires that came with the customers system.

 

How do Baluns work?

They "convert" the unbalanced coaxial line/output/input on the cameras to a balanced signal (thus the name, "BALanced/UNbalanced") for transmission over twisted pair cable. You need one on each end of the run, one to balance the signal from the camera, another to unbalance it to feed back into the DVR.

 

What cable is used with them?

Cat5e is used most commonly, because it's readily available and relatively inexpensive, but you can can use just about any pair of wire you want. Twisted pair (like Cat3, Cat5, Cat6, etc.) adds the benefit of additional noise rejection, but I've used baluns successfully with station wire (four conductors, such as is often used with alarms and intercoms), speaker wire... even lamp cord in a pinch.

 

 

 

How do you install a Balun on a cable?

Depends on the design. Some use screw terminals, some have "tool-less" punchdown terminals, some have an RJ-45 jack so you can just plug in a network cable (this DOES NOT put the camera on the network, it just allows you to use those types of cables and connectors).

 

 

 

Do you always use them for most CCTV installations now?

Almost exclusively. Cat5e is cheaper than coax (and with coax, you still need to run separate power - with Cat5e, you can run video and power over the same cable, and/or run multiple cameras on a single cable), it's easier to work with (more flexible), and it's future-proof - upgrading to an IP camera later is easy. And it helps limit the number of boxes of different cable I have to carry around in my van.

[johnny916 0]

Wow very informative thanks!! Just one more question, regarding the power supply on the Cat5 cable, am I supposed to buy some sort of connector for each end of the cat5 so that they will be compatible with the power connections on standard security cameras?

[johnny916 0]

Just watched a video on Balun's and they recommend doubling up on the POWER connections, but is this really necessary for cable runs less than 300 ft and DC powered? Because obviously I'll lose that one set of cables that I could of used for a second camera in the same area.

 

Also, which Cat5 cable is the best for balun's? There's cat5e, cat6, etc..

[Birdman Adam 0]

It all depends on the current draw. I'd say keep it under ~600mA or so (most cameras WITHOUT IR will use much less) if you use a single pair.

 

Using two pairs is essentially 18ga - good for at least 1A.

 

Current draw also depends on voltage (these are not resistive loads...). A camera that can accept 24VAC or 12VDC will use approximately half the current at 24VAC.

 

Any UTP cable will work just fine. Having the two wires in a pair twisted together is the key! So I'd just get whatever is cheap - cat5e is super-popular...

[Soundy 1]

One pair of 24ga. Cat5e is approximately equivalent to one 21ga. wire.

 

"Good for" depends on the draw and the distance, as well as the actual voltage the camera requires.

 

For an example, let's take a CNB VCM-24VF, which is rated for 2.2W power consumption. Let's say we want to put it 300' away, using two pairs for power. Using this handy calculator: http://www.netkrom.com/voltage_loss_over_cat5_calculator.html

 

2.2W at 12V is about 200mA (rough estimate), so plugging that into the calculator, using two pair, you get a drop of 0.7V, so if your power supply puts out a solid 12VDC, at the camera you'd see 11.3V. At 24V, current draw would be 100mA; drop rates about .3V

 

If you use only a single pair for power, the voltage loss is twice as much... so with 12V power, the camera would only see 10.6V; with 24V, it would get 23.4V.

 

If memory serves, the VCM-24VF will actually work with anything from about 10 to 30V, so you're probably okay either way, but you get the idea... they're a pretty robust and low-power camera though; others with higher power consumption (particularly those with built-in IR) will see much greater losses, and probably be a lot less forgiving of under-voltages.

 

Personally, I'd recommend using two pairs for the power if for no other reason than simplicity of installation.

[rory 0]

Just watched a video on Balun's and they recommend doubling up on the POWER connections, but is this really necessary for cable runs less than 300 ft and DC powered? Because obviously I'll lose that one set of cables that I could of used for a second camera in the same area.

 

Also, which Cat5 cable is the best for balun's? There's cat5e, cat6, etc..

For such short distances just use RG59 Siamese (that is CCTV cable) which is cheap (34 cents a foot in my area) and stop thinking so much about it, spend more time on the rest of the system. Or if for some reason you must run cat5 for video at least run 18 awg for power and make your life easier. You are over thinking such a simple thing, CCTV is not rocket science nor should it take up so much of your time.

 

BTW time as you add the cost of the baluns+shipping the cat5 and RG59 siamese is the same cost. Cat5 has its place but its not for every install especially not a small residential one.

[Soundy 1]

Keep in mind that prices in Rory's area aren't really relevant in the rest of the developed world. Siamese goes for about the same retail price here in Canada... IF you buy in bulk.

 

At a standard brick-and-mortar electronics retailer in North America, you're probably looking at 35c/ft., for Cat5, or around 10c/ft. in bulk <$100 for a 1000' box). A 500' box of Siamese at the same store is $160 (or $320 for 1000'). *Quality* baluns can be had for $5/pair.

 

Do the math. Be sure to factor in your installation time and the fact that Siamese cable is a PITA to work with.

 

Rory is correct on one point: you're WAY over-thinking things.

[johnny916 0]

Thanks, perhaps I am over thinking.. The last system I installed with regular CCTV cables and one out of 6 was bad. But at the time, I didn't have the connections to cut and make a new one. The Cat5e with Baluns sounds so much easier to work with. Even running it through holes without having to insert the whole damn connection piece sounds great.

[thewireguys 3]

Even if your pulling RG-59 you should be terminating the wire after it's installed. Using pre-termed wire is just asking for trouble.

 

But it agree with Soundy. All I stock for wire anymore is Cat5 and Cat6 plus some 16/2 for powering some housings. We also have been using MuxLab baluns so all we do is term with a RJ-45 and Cert the run then plug in the Balun. Makes for a much faster/cleaner install with less tools and connectors to stock and carry around. But keep in mind 95% of our installs are IP and the 5% is mostly moving analog cameras to new locations.

[Birdman Adam 0]

How do you "cert" a run?

 

I really do think cat5 is the way to go now, its definitely cheaper and easier to work with.

[Soundy 1]

How do you "cert" a run?

 

Simplified: plug a cable tester into it to confirm all wires connect through and to the right pins on both ends.

 

Ideally: using an actual network cable certification tool that will check for proper function up to 10/100/1000Mbps.

[johnny916 0]

From the wireguy "But keep in mind 95% of our installs are IP and the 5% is mostly moving analog cameras to new locations."

 

Wow really? Why is everyone going IP? What exactly is the difference between installing all IP cameras vs regular cameras with a DVR that can connect to the internet?

[thewireguys 3]

 

Ideally: using an actual network cable certification tool that will check for proper function up to 10/100/1000Mbps.

 

Yes this is what we do.

[thewireguys 3]

From the wireguy "But keep in mind 95% of our installs are IP and the 5% is mostly moving analog cameras to new locations."

 

Wow really? Why is everyone going IP? What exactly is the difference between installing all IP cameras vs regular cameras with a DVR that can connect to the internet?

 

 

System design flexibly, scalability and image quality/resolution are the main reasons I am seeing. I find that people just are not happy with there current analog systems and they want a better image qualty.

[Soundy 1]

From the wireguy "But keep in mind 95% of our installs are IP and the 5% is mostly moving analog cameras to new locations."

 

Wow really? Why is everyone going IP? What exactly is the difference between installing all IP cameras vs regular cameras with a DVR that can connect to the internet?

 

 

System design flexibly, scalability and image quality/resolution are the main reasons I am seeing. I find that people just are not happy with there current analog systems and they want a better image qualty.

Second all of this.

 

The one major limitation of analog video, is the analog video standards themselves - NTSC simply doesn't allow more than 525 lines of vertical resolution (625 for PAL). You can't transmit a higher resolution without abandoning those standards, which would pretty much void any compatibility or interoperability between cameras and recorders.

 

The primary way to get around this limitation, is simply to digitize the high-res video inside the camera, and transmit it over a network connection... functionally, not much different from streaming a movie or a YouTube video - data is data is data. So IP video largely came about as a way to achieve higher resolutions than analog would allow.

 

Beyond that, as thewireguys says, using a network gives you a LOT more options for laying out, wiring, controlling, and routing your video. If you have six cameras in an area, 300' away from your DVR... would you rather run six video and power feeds that distance, or just put a switch near the cameras and run a single uplink cable back to the DVR? Sometimes, this ability can save an install, or at least a hulluva lot of time.