Replace Cisco Power Injector with Non Cisco Power Injector

Posted on

This article will show you how to use non cisco power injector for cisco POE enable devices, this could be Cisco phone, Cisco Access point and other Cisco devices.
This is begun when we have several Cisco Phone 7940G without adaptor, to get the replacement adaptor is not easy, it’s required 48V DC and 0.38 A adaptor. Cisco Phone 7940G is POE capable device.
On the other hands we have several unused POE injector Motorola AP-PSBIAS-2P2-AFR for Motorola Access Point AP 6521, the output is 48V and 0.35A so slightly different with Cisco Phone adaptor.

Because I see that the different is slim I am sure that using Motorola power injector on Cisco phone 7900 series will works fine.
When I plugged the cable from Motorola power injector nothing happened with Cisco phone, so I quickly unplugged because I remember there is 48 volts current that may will destroy devices if not connected properly.
After searching on the internet I found that Cisco using different pin configuration, that is why Cisco POE devices must use Cisco power injector cannot use power injector from different brand.

RJ-45 pin cable configuration

Knowing this I make little modification with standard PIN configuration on RJ45 connector and it works with following configuration:

Replace Cisco Power Injector

As you can see on above picture that the cable colour is:

non cisco power injector for cisco poe devices - Replace Cisco Power Injector
Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8
Orange/White Orange Green/White Blue Blue/White Green Brown/White Brown

Orange/White Orange Green/White Brown/White Brown Green Blue/White Blue

This pin configuration is work and this should work with other power injector from different manufacturer to work with Cisco devices that able to use POE.

Although UTP cable have and RJ-45 connector each have 8 cable/pin, only 4 are used for data. Pin 1,2,3, and 6.
Pin 4,5,7,8 are reserved for telephone usage.
OK this wrap up my posting on Replace Cisco Power Injector with Non Cisco Power Injector I hope you find it useful. Please share this article.

Facebook Comments