manually changing unused lan pins into power over ethernet

[aurmol 0]

I have an NVR which doesn't have POE and neither the ip cam and their distance is 10 meters. Looking at pin assignment of an Ethernet cable.

 

http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm

 

One can noticed pin 4,5,7 and 8 are not used in a 10base setup (which is how the POE is possible.. does this mean all ip cam are 10base.. which one is 100base?).

 

I know how to connect jack to lan cable since I have a crimper and have done it several dozen times. Can I just connect the used 1,2,3,6 and make use of any of the unused 4,5,7 and 8 pin as the 12 volts line by connecting the adaptor to one end and female jack to another end and plugging it into the 12 volt power input of the ip cam?

[Q2U 0]

I have an NVR which doesn't have POE and neither the ip cam and their distance is 10 meters. Looking at pin assignment of an Ethernet cable.

 

http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm

 

One can noticed pin 4,5,7 and 8 are not used in a 10base setup (which is how the POE is possible.. does this mean all ip cam are 10base.. which one is 100base?).

 

I know how to connect jack to lan cable since I have a crimper and have done it several dozen times. Can I just connect the used 1,2,3,6 and make use of any of the unused 4,5,7 and 8 pin as the 12 volts line by connecting the adaptor to one end and female jack to another end and plugging it into the 12 volt power input of the ip cam?

 

Yikes. Why would you not simply deploy a POE injector?

[aurmol 0]

I have an NVR which doesn't have POE and neither the ip cam and their distance is 10 meters. Looking at pin assignment of an Ethernet cable.

 

http://www.zytrax.com/tech/layer_1/cables/tech_lan.htm

 

One can noticed pin 4,5,7 and 8 are not used in a 10base setup (which is how the POE is possible.. does this mean all ip cam are 10base.. which one is 100base?).

 

I know how to connect jack to lan cable since I have a crimper and have done it several dozen times. Can I just connect the used 1,2,3,6 and make use of any of the unused 4,5,7 and 8 pin as the 12 volts line by connecting the adaptor to one end and female jack to another end and plugging it into the 12 volt power input of the ip cam?

 

Yikes. Why would you not simply deploy a POE injector?

 

Because the ip cam is not POE capable. One must plug a separate 12 volts adaptor into its power.. so it's not theoretically impossible to use 2 of the pins right.. before I used to install internet café lan network system so very familiar with pins and had crimped over a hundred lan cables and even have tester for each pin..

[Boogieman 1]

I think q means to use something like this...its cleaner http://www.amazon.com/Passive-Injector-Splitter-5-5x2-1-Connector/dp/B00NRHNPUA/ref=sr_1_4?ie=UTF8&qid=1416890338&sr=8-4&keywords=passive+poe&pebp=1416890383260

make sure you get the right size..

or

http://www.amazon.com/SMAKN%C2%AE-Gigabit-Passive-injector-ethernet/dp/B00LS5OCTQ/ref=sr_1_6?ie=UTF8&qid=1416890338&sr=8-6&keywords=passive+poe

[Spark 0]

I think you need to realise there is a distinct difference between POE and just 'using some spare pairs in an ethernet cable'. It is an common and unfortunate misconception.

There is a standard for POE (802.3af, 802.3at) and power and data can coexist on the same pairs.

POE is a nominal 48VDC, or higher, supply.

POE involves handshaking between the power source and powered device.

 

10BaseT and 100BaseT are similar in that they both only use two pairs.

Gigabit or 1000BaseT uses all four pairs so would prevent you from doing what you are considering.

 

If you do use the spare pairs in 10BaseT or 100BaseT cable, don't plug a POE device in, because what you have isn't POE, it's PUSSPIAEC.

[Securame 0]

One can noticed pin 4,5,7 and 8 are not used in a 10base setup (which is how the POE is possible.. does this mean all ip cam are 10base.. which one is 100base?).

 

I know how to connect jack to lan cable since I have a crimper and have done it several dozen times. Can I just connect the used 1,2,3,6 and make use of any of the unused 4,5,7 and 8 pin as the 12 volts line by connecting the adaptor to one end and female jack to another end and plugging it into the 12 volt power input of the ip cam?

 

Yes, you can do it. But no, that is not how POE works.

[MaxIcon 0]

As Q and Boogieman suggest, your best bet is using a passive POE injector/extractor set. Whatever you put in one end comes out the other, so you can use your existing power supplies.

 

Yes, you can do this manually by breaking out the appropriate pins and connecting them to the appropriate size power supply jacks, but passive injectors are cheap.

[jeromephone 6]

What does 30 feet of 18/2 cost? 3.00? Just run a power cable and then you don't have a cobbled up cat5 that someone has to figure out later.

[aurmol 0]

how much wattage can a typical cat5e cable take? Note the wire is so tiny.. assuming the camera has 12 watts (12 volts x 1 ampere), won't be 12 watts heat the wire? or cause it to deteriorate faster? Note that in POE, 48 volts is used because

 

"The IEEE has standardized on the use of 48 VDC as the Injected PoE voltage. The use of this higher voltage reduces the current flowing through the CAT5 cable and therefore increases the load and increases the CAT5 cable length limitations. Where the maximum cable length has not been a major consideration some vendors have chosen 24 VDC and even 12 VDC as their "injected" voltage."

 

but Cat5 cables are not all the same.. could all take the highest wattage possible in an IP cam with say 24 IR LEDS?

I guess POE IP cam have lower wattage (between 5 and 6 watt) than non-Poe cam (12 watts or so). Do you agree?

[Korgoth Of Barbaria 0]

how much wattage can a typical cat5e cable take? Note the wire is so tiny.. assuming the camera has 12 watts (12 volts x 1 ampere), won't be 12 watts heat the wire? or cause it to deteriorate faster? Note that in POE, 48 volts is used because

 

"The IEEE has standardized on the use of 48 VDC as the Injected PoE voltage. The use of this higher voltage reduces the current flowing through the CAT5 cable and therefore increases the load and increases the CAT5 cable length limitations. Where the maximum cable length has not been a major consideration some vendors have chosen 24 VDC and even 12 VDC as their "injected" voltage."

 

but Cat5 cables are not all the same.. could all take the highest wattage possible in an IP cam with say 24 IR LEDS?

I guess POE IP cam have lower wattage (between 5 and 6 watt) than non-Poe cam (12 watts or so). Do you agree?

 

802.3at - ~15.4W (PoE)

802.3af - ~30W (PoE+)

There is even High PoE and it allows you to power PTZ cameras that needs about 60W of power.

[MaxIcon 0]

In general, larger wires are better, and Cat6 is better than Cat5 for POE. In practice, it's not a big deal if you're using 802.3af POE. If you're using power injectors, it's a bigger problem, as you noted, because of the high current at lower voltages.

 

The 802.3af 15.4W spec is at the switch end; the spec for the device end is 12.95W, which takes into account worst-case Cat5 spec cable resistance over 100M. Some cams pull this much power, but using Cat6 reduces the loss in the cable and gives a bit more headroom.

 

You do want to avoid copper-coated aluminum wiring, which you'll find in bottom end cables.

[Horizon 0]

Hi Korgoth.

You're a bit out of date there.

The POE++ standard allows 90 watts to be fed into a Cat5 cable, although you can expect to lose 10 to 20 watts over a 100m length. Cat6 has less losses. I don't know whether there are any switches that support this yet. The power supply requirements (90W per port) would make them a little pricey.

[aurmol 0]

the wires in the cat5 is said to use awg 22 which can reach up to 3 amperes.

 

my camera is big with 42 pcs of LED and it's power supply is 1A, 12V. Assuming it's 12 Watts (12V x 1A)... the manufacturer doesn't want to put the wattage rating in the spec (maybe may scare the customers away). What do you think will happen to a 1 ampere current passing thru the awg 22 wires 24 hours?

 

and what is the wattage per LED of the 42 pcs?

 

my lan cables are inserted into very tight small pvc inside cement and I can no longer replace just one without pulling all the wires and much work and hundreds of dollars of cost. If the wire keeps heating, would it just melt.. some years ago.. I have some electrical wires where the wires themselves get black. What other problems would happen if the cat5 wires keep heating? would this really occur at 1A 12 volts 24 hours or should I buy a POE cam that is 802.3af (and sell off my non-POE cam)?

[johnnycw 0]

I'm running an anolog PTZ with IR using a 12v passive injector/extractor with about a 30m run with Cat5. The camera's original power supply is 2A and the camera specs state 20 watts with IR on. The setup has been running reliably for nearly 3 years 24/7.

 

Maybe I've just been lucky.

[MaxIcon 0]

It's hard to say for sure without more data. If the wires are undersize or poor quality and the run is long, you're more likely to have problems, but if they're good quality and/or your run is shorter, you should be OK. Many people have run passive POE for years with no issues, as johnnycw mentioned.

 

If there's a lot of power dissipation along the wires, you'll likely have trouble with the cam, especially when the LEDs come on at night. Large power drops cause the voltage at the camera end to drop, which can make it stop working, so that's likely to happen long before you see any damage from overheating.

 

Best bet for measuring the power is to get a device like the Kill A Watt. Plug the power supply into it without the cam connected, note how much it draws, then connect the cam, and you'll know how much power the cam uses, amd can then calculate the current.

 

It's unlikely they'd give you a 12W supply for a 12W cam. These Chinese wall-warts can be notoriously unreliable, and it's always a good idea to over-spec them.

 

LED power draw depends on a bunch of things. You can't know the power of the LEDs without measuring it on the board, but with 42 of them, they're guaranteed to be low power, probably under 0.1W each.

 

I'd suggest hooking it up with a passive injector pair and see how it does.

[Horizon 0]

As MaxIcon says, it depends on a lot of things.

The main limitation is the maximum temperature that the cable can tolerate. This is typically between 60 and 75 degrees celcius, depending on the manufacturer. Cable rated for outside use might handle more heat.

So what you need to do is figure out what the maximum ambient temperature is (ambient, as in the temperature in the area that the cable is installed), and calculate (or guess) how much heat the current through the wire will cause. You need to ensure that when you add the heat caused by the current to the ambient temperature, the total does not exceed the temperature rating of the cable. Otherwise the cable's insulation will prematurely age and fail.

 

The usual recommendation is that the current shouldn't cause an increase greater than 10 degC.

Typically for Cat5, you can carry 0.6 amps in all eight conductors (4.8A total), and for Cat6, you can carry 0.8 amps in all eight conductors . These figures are based on carrying current through bundles made up of dozens of Cat5/6 cables, with a 10 degC temp rise on the hottest inner wires. Since you are only using a single Cat5/6 cable, you can probably carry an amp or more, but there are so many variables that it's hard to make a recommendation.

 

For 12 volt cameras, your main limitation will be the voltage drop.

The beauty of Power Over Ethernet is that the high voltage it uses minimises the effect of voltage drop.

[aurmol 0]

Remember pin 4, 5 and 7, 8 not used.. I initially just used pin 4 and 7 as + and - 12V.. but read in POE.. 4,5 are used as positive and 7,8 as negative.. so I can connect the positive (+) to both 4,5 and negative (-) to both 7,8? Ordering at amazon would take 2 weeks and I already made the hybrid wires. In those passive ejectors.. do they use both 4,5 as positive? I guess the power would distribute better in 2 wires than 1.

 

Anyway. Are single wires in the Cat5E really Awg22 and maximum ampere 3A?

[aurmol 0]

btw.. this is the camera....

 

http://en.jovision.com/Products/ProductView.aspx?id=131

 

It is about one foot long and has 42 LEDs... anyone familiar with such length camera? the wattage is not written... and there is no included power supply... the local store just supplied 1A 12 volts adapter. If you have something similar to this.. a dahua, Hikvision, Axis or others.. pls. mention what is the wattage indicated.

 

After 30 minutes, the camera is hot and the adapter.. so I figure the wires must get hot too.

[aurmol 0]

Here's the spec of the data cable Cat5e I'm using...

 

http://pdf.datasheetarchive.com/indexerfiles/Datasheet-027/DSA00474140.pdf

 

note it has Awg 24 which has maximum ampere of only 0.577 ampere

 

http://www.cablesandconnectors.com/wiregauge.html

 

In my original adapter with only pin 4 as + and 7 as - 12 volts and assuming the camera mentioned in the message prior to this draws in 1 ampere maximum at 12 volts (12 watts).. it may not survive... but using pin 4 and 5 as + 12 volts can split the say 1A into 0.5A.. but I the camera draws in more than 1 ampere (the company refuse to write the power requirement), then the cable won't last for years.

 

therefore based on the data.. I think I must get a new POE cam and sell the old one...

[Korgoth Of Barbaria 0]

Hi Korgoth.

You're a bit out of date there.

The POE++ standard allows 90 watts to be fed into a Cat5 cable, although you can expect to lose 10 to 20 watts over a 100m length. Cat6 has less losses. I don't know whether there are any switches that support this yet. The power supply requirements (90W per port) would make them a little pricey.

 

Thanks m8!

Btw. why there are no PoE powered laptops? o.0