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Author Topic: X40 passive PoE limits  (Read 2626 times)


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X40 passive PoE limits
« on: October 21, 2012, 07:58:01 AM »

Have a X40 PTZ and tried installing the PoE kit yesterday.   Ads say 100' limit and I'm close to that.  But I get no power with the power supply located in the basement to the second story, outside deck.  The PoE works with a short cable (20') so know that it is OK.  Anyone know the practical limits?

Also, has anyone tried a slightly higher voltage over a longer distance?


Brian H

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Re: X40 passive PoE limits
« Reply #1 on: October 21, 2012, 09:55:08 AM »

If you have no video at all with the 100' cable. Have you verified the cable is good and does not have a problem?

Are you using CAT5 or CAT6 and what gauge wire is in it?
Passive Power Over Ethernet many times uses pair 4&5 for + voltage and pair 7&8 for - Voltage.
The amount of voltage dropped in the cables depends on what gauge it is and how much current the camera draws.
I found a chart of typical wire resistances for 100 feet and used room temperature.

One Pair of wires to the camera is R/2. One Pair back from the camera is R/2. Total= R/2 + R/2 or the resistance of one wire on the chart.

#22 R=1.64 Ohms  If the camera draws 1 Amp. 1x1.64=1.64 volt drop
#24 R=2.62 Ohms  If the camera draws 1 Amp. 1x2.62=2.62 volt drop
#26 R=4.16 Ohms  If the camera draws 1 Amp. 1x4.16=4.16 volt drop.

I believe I read some of the cameras use closer to two amps. If that is the case double the voltage drops in the above list.
Also I would say the maximum current would be when the pan or tilt motors where running. So the voltage may go up and down as the current changes.

100' maybe pushing the limits for a passive POE kit.

Some of the more expensive POE Injector kits. Use a 48 volt supply on the injector side and a voltage regulator in the unit being powered end.
Some have a switch for 5 or 12 volts on the receiving end. Problem I have seen is most say the 12 volt choice is at 1 amp and I believe the cameras need more current.

Possibly using a higher voltage supply on the X10 power injector side could work but you would have to custom pick a voltage to compensate for the voltage drop, at enough current. To be close to the 12 volts the cameras need.

Not also risking damage that x10 could say voided the warranty.
« Last Edit: October 21, 2012, 10:41:54 AM by Brian H »


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Re: X40 passive PoE limits
« Reply #2 on: October 22, 2012, 06:14:27 PM »

I made sure the camera was working properly before trying the PoE.  For now, I've got the power supply plugged in outside with a plastic bag and duct tape for waterproofing.  I can make this work, but only because there is an outlet nearby.

I think X-10 should put a more reasonable limit on the passive PoE in their ads.



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Re: X40 passive PoE limits
« Reply #3 on: December 15, 2012, 03:57:15 PM »

Quick fix solution. I used the camera wireless to get to a spot and tagged in the POE at the last 20 feet using the ethernet POE.  That may help.
« Last Edit: December 15, 2012, 04:20:10 PM by Robotux »
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