POE Injectors Instead of a POE Switch

[TheHawk]

As the title suggests i was wondering if anyone has ever encountered POE injectors in with the switch and patch panel?

The reason i ask is when i first started working where i am at the moment they had this bolted to wall.

 

http://i879.photobucket.com/albums/ab356/jizmond69/null_zps6915c486-1_zps21b73a1e.jpg

 

I queried it with my colleague and he explained that it wasn't it his doing. We are still trying to work out they didn't put in a POE switch in (which we have now done) or put the injectors in at the desks.

[DrPerceptron]

Depends when it was done and the switches etc.

 

We have a load of Cisco PoE Injectors because our 48 port switches (HP Procurve) dotted around wouldn't power the access points for some reason - it was cheaper and considerably easier to get Injectors rather than a pair of 24 port switches and swap out the 48s.

 

Also, all the power is with the switches etc and not at the other end of the link... because that's what PoE is for/should do... when it works.

Edited April 23, 2013 by DrPerceptron

[crc-ict]

My old place used to have the odd few injectors housed in cabinets to run Wireless APs.

 

It was tidier and easier to have them in the cab where there was already power, and not to have to install power at the location of each WAP.

[sparkeh]

Yeah I have PoE injectors in my cabs.

Why? Because I don't need many PoE points in each cab, buying a new switch for each cab was a waste of money when we had perfectly good switches and I could buy a 4 port injector. Its tidier to house them in the cab than with the device.

However, if I had a lot of devices then yeah I would probably go for a new PoE switch.

[TheHawk]

The thing is these were for the phones and few AP's and there's POE switches in all the other building for our wireless AP's. This was in the main server room our core switch doesn't support POE but we have now done an up link to a POE switch with enough ports for the phones and it looks a lot tidier than 15 injectors and two extension leads screwed to a bit of chip board! I wasn't saying that injectors were bad just having them in such high numbers when they could of spent half the amount of money and had a neater more manageable solution! Edited April 23, 2013 by TheHawk

[sidewinder]

That is ridiculous. However years ago my old school used to have stacks of Cisco injectors in each cab, I think because their PoE wasn't standard, or it was before the standard had been finalized, can't remember.

 

I'd still use them in areas where there are only 1 or 2 PoE devices but thats about it. I've also just acquired a free 6 port rackmount PoE injector from a friend which will handle a few of our access points for a while, but generally I'd rather PoE switches

[shadowx]

Our phone system with inbuilt 10 port POE switch wasn't big enough to support all our phones, our existing cabinets have no room in them for POE switches so our solution was just to use the injectors on people's desks unless there was a space issue or if they were special (Like me!) in that case the POE injector is usually in the cabinet pumping POE out towards the phone.

 

Although *adjusts health and safety helmet* is that amount of adapters safe?! That's a lot of 4 gangs being used and all of those transformers so close to each other is going to generate a massive amount of heat, if for some reason something went iffy with the power... Well, I hope your fuse boxes are in order!

[mrbios]

I use PoE injectors in my cabs, but mainly because each cab only ever needs a max of two PoE points.

 

When one of our new buildings was built in 2009 we put a PoE switch in thinking we would need it but only ever had it using two ports which was pointless and a big waste of money.

 

Only use mine for wireless APs which are obviously very spread out anyway.

[TheHawk]

It was crazy it was a fire waiting to happen so the first chance we had we gutted it and its now 100% better. Not only was it a fire waiting to happen it was also causing lots of CRC errors on switch. Since we got rid of them last week we have had no errors occur. Just out of curiosity i priced up how much 15 sonic wall gigabit injectors would cost and it came in at nearly double the price of a 24 port POE HP switch we put in.

[MatthewL]

Where I used to work we had PoE switches except on sites where there was only 1 or 2 devices and we would put an injector in, ten time easier and cheaper than swapping out switches.

[pete]

Our rule is "3+ injectors in a cab means you buy a POE midspan or switch, depending on what's appropriate". They create heat out of all proportion to their size.

[wickit]

Our rule is "3+ injectors in a cab means you buy a POE midspan or switch, depending on what's appropriate". They create heat out of all proportion to their size.

 

Sounds like a good rule to me

[howartp]

Sounds like a good rule to me

I've just had to put a lot of POE across site.

 

I was seriously looking at Rackmount POE Injectors by Planet to give me POE for my sitewide WiFi deployment without the cost of replacing switches with POE models and ending up with redundant switches in my storeroom.

 

(Un)fortunately I then realised we wanted Gig speeds to the APs, and it took me far too long to realise that buying a Gig POE injector and putting it on a 100mb port won't give me Gig! (Durrh!)

 

So I've had to cough up for Gig switches with POE. (Non-POE Gig switches plus these injectors, even 4/8 port injectors, worked out more than the cost of just getting Gig POE switches)

 

Hope this helps anyone who browses this thread in future.

 

Peter