Cisco Catalyst 2960-48TT Switch Power Supply

Question

What exactly is the power supply for the Cisco Catalyst 2960 Switch?

This is probably a very dumb question. I bought one and while it had 2 terminals for power adapters it had no power cords packaged with it. I asked the reseller about this and they told me

This unit doesn't use power cords. It has an internal power supply.

To her point, I do see in the data sheet that is says this:

● Customers can provide power to a switch by using the internal power supply. The connector is located at the back of the switch. These switches do not have a redundant-power-supply port.

● The internal power supply is an auto-ranging unit

● The internal power supply supports input voltages between 100 and 240 VAC

I apologize, but this is all very new to me (I just bought it to help me learn) and I'm struggling to understand it.

The repeated references to an "internal power supply" seems to support the reseller's statement. However (a) it doesn't seem to work when I wire it to a router and host and (b) the data sheet is also talking about a "connector" and "input voltage", which sounds like it still needs a power adapter and that this "internal power supply" isn't what the reseller was implying.

I think the answers are that

1. The reseller misconstrued the hardware that's being called an internal power supply (and they should owe me a cable) and

2. It does need an adapter and this is one possibility

However I'm still not 100% sure and I would like to understand this "internal power supply" concept.

Answer 1

Most Cisco 2960 switches use regular IEC C13 cords just like you would use for most PCs and displays. Some switches may offer other power options such as 48v DC power. That would depend on the specific model number of the switch, 2960 is just a broad switch family number. You can find an exact model number for your switch by looking for a small white barcode tag on the switch.

By internal power supply they just mean that inside of the switch case is the device which will convert the AC power from the wall to the various DC power voltages needed to operate the switch. Think of it as similar to the power supply box found inside of a desktop PC (another "internal power supply") compared to typical home routers which use "wall warts" (external power supplies). The supply is not quite the same as a PC supply (obviously it's smaller for one thing) but it serves the same purpose.