To enable full radio capability of some of the latest access points, 802.3bt power source is required. If you don’t or can’t have a 802.3bt capable switch, power injector might be the right choice for you.
For Cisco’s CW9179F, CW9178I, CW9172H, and other APs, the correct injector is CW-INJ-8. It takes AC power and injects 802.3bt Type 3 Class 6 (up to 60 Watts) into your twisted pair copper cable, and it is designed for up to 10 Gigabit Ethernet.
Apart from documentation, there is just the power injector in the box. If you don’t have one in your “box of cables” already, order an IEC C13 power cable separately. It is not included.
When is injector not the best choice?
Here is my rule of thumb. If you can, power your AP using a switch. Why? Power injectors in general introduce extra points of failure. Unlike switches, they can’t be remotely monitored or controlled.
Now, if there is no switch available, use a power injector. Site survey, assuming that AC power or battery pack with inverter is available, is another good use case. Or lab use – for when you don’t have a 802.3bt switch.
Hardware overview
There are no surprises on the top side. Note the LED on the top right.
Here is a quick look at the label.
The injector has RJ-45 input, RJ-45 output, and AC power connector which accepts standard IEC C13 cable.
Status LED
Solid green LED indicates that a valid IEEE 802.3bt or 802.3at AP is detected, and the AP consuming PoE power.
Very occasional flashing green indicates that AC power is provided to the injector itself. Don’t expect it to be solid green with no AP connected.
Let’s test it
Microchip makes this pocket-sized PoE tester. Let’s see what we get at the output of this power injector. As we expected, 802.3bt Type 3 Class 6 (up to 60 Watts) it is.
Official documentation
Always refer to the official documentation, please.