https://www.cablemodeminfo.com/quicktip-cabling-power-ethernet.html-ssi
Does this work?? Can you do this at the patch panel end, and do a poor man's POE??-- Running the 24 volts over the blue & brown pair to the phone. Or is this just a bad idea?

We have several wall-mounted phones that need to have power, but have no power outlet near them. We're trying to find a nice, easy solution--but perhaps there is none. An expensive POE switch is not an option at this point.

I would imagine that it would work. POE switches just send the power over those 2 pairs.

Well, that's what I was thinking too. We'll try it out first here in the shop. If it works, it will solve a big issue with an install coming up.

In fact, this seems to me to be a big issue with the IP systems all over. The AC adapters are fine for desks---but when you have wall-mounted phones---you run into a big problem. It looks real cheesy. It's like taking a step backward in technology.

Well I had to run a camera in an area that had several unused cat 5e cables running to it. I used one cable for the video and another cable for power. I took the pairs and twisted them together and attached the power connectors.

But POE switches are coming down in price so much it almost makes sense to just get them....even if the other way does work, seems like it could cause more headaches in the long run, besides, if you only need a few ports for wall mounts and such and AC adaptors are OK for the rest you can get a 8 port POE switch for real cheap.

Steve

Netgear Prosafe FS108p and FS116p are small port density PoE Switches. They have 4 and 8 ports respectively of PoE capability and are pretty damn flawless unmanaged switches. I use them a lot in very small workgroup situations.

If you accept the fact that using that method you mentioned above means you have a live-wire then I see nothing wrong with it. That method is what valcom recommends on their powered PA Horns (minus the terminated connectors).

If you are pretty enough with your splicing and have lots of electrical tape you can make a fairly clean looking install.

For safety's sake I would clip the power pairs from running to the modular plug.

Have u considered a POE injector?

You're right!! I had done several googles of POE stuff, and all that came up were very expensive Cisco switches. I just thought that even the less expensive ones were like one-half---and THAT was even too much.

I then checked with our resident IT guys, and they showed me some decent switches for some decent prices.

We did look at some injectors and for just 4 or 5 phones they are a good deal---but the prices for a 24 port switch was pretty decent, so....

So we will be replacing the current switches with 24 port POE switches if we can. The dollar figure doesn't seem to be that huge. Thanks to all for the in-put.

Beware,,, not POE devices are created equal. If the manufacturer says 802.3af then the voltage is supposed to be 48vdc. I recently bought some power injectors at www.winncom.com and installed them on some access points. Price was very reasonable.

I have had to do this in the past,and it worked using the transformers that come with the equipment.

I have found the injectors for $30 or so. I believe it was at VOIPsupply.com

My concern with chopping the power cord and connecting it this way would void the UL/CSA/CE listing. Just about anything that uses electricity must have these listings to be sold in the US and Canada. By altering the factory assembly, you would be voiding the warranty AND violating UL/CSA requirements.

Leviton does make a wall phone jack that was designed for this purpose, but it was made to be used with cordless phones. I don't know if it would work for this application or not unless they've come out with an 8P/8C version.

Thanks. All of the phone AC adapters are 24 volt. If the POE 802.3f device is made for 48V--then that wouldn't be very good. I've got some time before the install to get as much research done as possible. Next week we go for our training. Should be fun.

Chopping the power cord is our "last resort" option. With some of the inexpensive power injectors---that seems to be the way to go if there are only 3-5 phones that you have to do that for.

If the phones are listed to work with 802.3af PoE, then all you need is a PoE Switch. Always check with the MFG.

Here is an adapter for powering legacy devices with POE


Click here for details.

Linksys also makes splitters like this.

Also keep in mind that just because the plug-in power cube for your device is 24V, it does not necessarialy follow that your device also requires 24V for POE. Check the manufacturer's specs.

There are a lot of different POE schemes out there. The main ones are IEEE 802.3af and the Cisco proprietary scheme. But there are many others. Also, newer Cisco phones may use the IEEE 802.3af standard rather than the Cisco standard.

Also pay attention to POLARITY. The Cisco proprietary POE uses different polarity than the IEEE 802.3af POE. I.e., the positive and negative wires are reversed.

What is shone in the article is NOT POE. It is just using un-used conductors to extend the power.