Power for standalone IP camera and 3G router

[RustyJL 0]

For a standalone arrangement using 12V battery

 

Acti IP camera likely the KCM5611

 

Cradlepoint MBR95 3G router

 

POE splitter injector - http://www.ebay.com/itm/PoE-Splitter-PoE-Injector-2port-RJ45-1port-DC-5-5mm-2-1mm-input-/280999243490?pt=US_Network_Switch_Power_Supplies&hash=item416cdc2ee2

 

How easy is it to chop down the DC plug on the MBR95 and attach alligator clips to run it off 12V?

[buellwinkle 0]

The ACTi KCM-5611 can be powered by 12V and you can certainly cut the wires from a power adapter for the cradlepoint.

[RustyJL 0]

The ACTi KCM-5611 can be powered by 12V and you can certainly cut the wires from a power adapter for the cradlepoint.

 

Thanks mate, I knew about the 12V supply to the camera but would like to run a Cat5 cable from the router end so that I only need one power source. Just wasn't sure if I could cut that cable on the router and run 12VDC straight into the router. Do you know if it is a proprietary power plug that goes into the Cradlepoint or is it available at any electronics store?

[buellwinkle 0]

Looks like an ordinary connector on ours. Probably get it at any electronics supply store. Be careful on pushing a few amps of 12V through Cat5. If it's a meter or so, maybe fine but you may lose half the 12V if it's a 50m cable. Cat6 or 7 may help but it may pay to run a thicker gauge wire just for the 12V at the same time you run the Cat5.

[RustyJL 0]

Looks like an ordinary connector on ours. Probably get it at any electronics supply store. Be careful on pushing a few amps of 12V through Cat5. If it's a meter or so, maybe fine but you may lose half the 12V if it's a 50m cable. Cat6 or 7 may help but it may pay to run a thicker gauge wire just for the 12V at the same time you run the Cat5.

 

 

Ok. I thought you could push 12V through Cat5 cable up to 100m from the POE?

[buellwinkle 0]

You can, but you won't have 12V at the other end, even with regular PoE, 15.4W is really 12.9W at the camera 100m away, but that's 48VDC, a lot different with 12VDC.

 

But it's easy to figure it out, Cat 5 is typically 25 gauge, you know the voltage you start out with (12VDC), you know the distance, and you know the amps needed. Plug them into a voltage drop calculator and see what you have. Gives you the power loss in volts, the percentage and how many volts you have at the end.

 

http://www.calculator.net/voltage-drop-calculator.html

 

Plug in 48VDC, 25 gauge, 100m, .22 amps (10.7w for the camera), you'll see the voltage drop is nominal, down to 43V.

 

Not so much with 12VDC and 1.4A (8.5w to power the camera), the best the calculator can handle is 40m (above that it says it's zero), you would have very little left.

[RustyJL 0]

So for a short run of Cat5 cable you would use POE, otherwise have the power going direct to the IP camera and you could have up to 100m of Cat5 to send the data back to the router?

 

Most of the time I would say that the camera will be very close to the router and power supply, but I can envisage situations where I would want to have the camera some distance from the router/power supply.

[buellwinkle 0]

Most people use standard PoE but for 12V, I would limited to very small runs, a few meters at most.

[RustyJL 0]

Most people use standard PoE but for 12V, I would limited to very small runs, a few meters at most.

 

I must have misunderstood POE...

 

So is standard POE 48VDC? Can you feed 48VDC POE to a device that only takes 12VDC over POE?

 

Sorry I am confused now!

[buellwinkle 0]

PoE typically refers to the 802.3af standard, 48VDC but you are running off a battery, so you likely want to keep everything 12VDC so you don't have conversion losses. The camera you mention can run off 802.3af PoE which is 48VDC OR it can run off 12VDC, but not both at the same time.

 

There are non-802.3af PoE cameras, the only one I know is Ubiquiti that uses 24VDC for it's cameras and sells 24VDC PoE switches for that purpose, but that's really an oddity and just about everything that refers to PoE in the surveillance camera business is referring to 802.3af or 48VDC.

 

Now yes, they sell PoE splitters (not to be confused with injectors) that are 5VDC or 12VDC and their purpose is to run non-PoE cameras like a Foscam that have 5VDC or 12VDC power supplies. These splitters have a 12VDC power supply on one side, and 12VDC plug on the other.

 

Just follow the teachings of Georg Ohm and you'll be OK.

[RustyJL 0]

Buellwinkle you are a good man. Thank you for clarifying this!