Why That Little Black Box on Your Network Might Be Causing Big Problems

When we're called out to investigate an unreliable network — dropouts, slow speeds, access points that keep going offline — one of the first things we look for is a PoE injector. More often than not, we find one. And more often than not, it's at least part of the problem.

Here's what they are, why they get used, and why a properly designed network shouldn't need them.

What is a PoE injector?

PoE stands for Power over Ethernet. It's a way of sending electrical power through the same cable that carries your internet data — so a device like a WiFi access point or security camera only needs one cable running to it, not a separate power cable as well.

A PoE injector is a small plug-in device — usually a little black box — that adds power to a cable when the switch or router it's coming from doesn't supply power on its own. Think of it as a workaround: the switch doesn't do PoE, so you add an injector to make up for it.

Why do installers use them?

This is where the story gets a little more interesting — and it's not simply about cutting corners.

UniFi access points are increasingly stocked by electrical wholesalers alongside standard data cabling products. This means electricians who do data cabling work can now walk into their local trade supplier and pick up UniFi hardware the same way they'd buy a GPO or a light fitting. That's actually a good thing — it's made quality hardware more accessible.

The problem is that the same wholesalers often sell PoE injectors alongside the access points as the standard "power solution." It's the path of least resistance — the injector is on the shelf, it's familiar, and it gets the access point running. For an electrician whose core expertise is 240V wiring rather than network design, this is a completely understandable starting point. They're not doing anything wrong — they're using what's available to them and doing their best to deliver what the client needs.

The gap is one of specialisation. Installing data cabling and mounting access points is well within an electrician's skill set. Designing and commissioning a managed network — with a PoE switch, a controller, proper VLANs, and roaming configured correctly — is a different discipline that requires specific networking experience. It's not a criticism of electricians; it's simply a different trade. A network specialist wouldn't wire a switchboard either.

The result is that many Southern Highlands homes end up with good-quality access points running on an incomplete foundation — and the injectors are usually the most visible sign of that.

So what's the actual problem?

Several things, and they tend to compound each other.

They're a single point of failure

Each injector powers one device. If the injector fails — and they do fail, often without any obvious sign — the device it's powering goes offline. An access point stops broadcasting. A camera stops recording. Because there's no central management telling you something's gone wrong, you often don't find out until someone notices the WiFi is down in that part of the house, or you go back to check camera footage and find a gap.

They create a messy, unmanaged setup

A properly designed network has a managed PoE switch at its centre — one device that powers and monitors everything connected to it. With injectors scattered around, you lose that oversight entirely. There's no way to remotely reboot a device, check power draw, or see which devices are online. When something goes wrong, you're left guessing.

They often deliver inconsistent power

Not all PoE injectors deliver clean, consistent power. Cheap ones in particular can cause access points and cameras to behave erratically — connecting and disconnecting, running at reduced performance, or simply dying earlier than they should. This produces exactly the kind of intermittent, hard-to-diagnose problems that waste hours of troubleshooting time.

What should be used instead?

A managed PoE switch. This is a single device that sits in your comms cabinet and powers every access point, camera, and other network device in your home or property through their ethernet cables. It costs more upfront than a handful of injectors, but it's more reliable, easier to manage, and a fraction of the long-term headache.

In UniFi networks — which is what we install — the switch, access points, cameras, and router all communicate with each other and can be monitored and managed from a single app. That level of visibility simply isn't possible when power is being delivered by a collection of anonymous black boxes.