I recently picked up this switch on eBay. But I can’t find any info on whether or not it’s safe to connect a non-PoE device to it. Does anyone have familiarity with this switch and can advise on whether or not it would be safe to connect a non-PoE device up to it?
TL-SG3424P | JetStream 24-Port Gigabit L2 Managed PoE+ Switch with 4 Combo SFP Slots | TP-Link
Most all POE switches do not put out power to non POE devices unless you implicitly tell them to do so. It should be fine.
If you see the phrase “802.3at/af-compliant” (could also include “bt”) in the product description, then you can rest assured that it will not fry anything. The 802.3 PoE standards specify a handshake protocol that tells the switch how much power to supply (possibly none), so that when you plug in a non-PoE device, there’s no issue.
If you see a switch that says “passive PoE” (aka “always on”), then you need to be careful, because that means the switch does not use the 802.3 handshake, it just powers up the cable at all times.