Why does my UPS break AC adaptors?

Question

I've got a couple of my AC adaptors fail at different times during what I assume were power spikes, while being connected to my UPS. It's a pretty old APC 500 which I use only to back up my router and external hard drive. Though it's couple of years old and I havent changed the battery ever it still gives me around 5 minutes of power so I can shut down everything properly.

First when my router's AC failed I thought it was just faulty, then later when hard drive's AC failed also, I started to think that the problem is the UPS as other AC that were connected directly to the grid stayed fine.

So the question is: should I replace my UPS with a newer one, or is the whole idea of connecting appliances AC adapters to UPS just wrong and it's only for PC ACs.

Answer 1

Have you replaced the power adapters and found that the devices still work? Have you bench tested the failed power adapters or tried them on other devices (assuming you have another device with the same plug and power requirements)?

If you mean that both the power adapters (i.e. “wall wart” or inline brick) for your router and external HD have gone bad while attached to your UPS, then maybe your UPS is the problem. I would find it abhorrent that a UPS would fail a way that would destroy a connected device's power conversion hardware, but I suppose it is possible.

It should be fine to power non-PC devices through a UPS. You would not want to run high-draw devices through a UPS (think Blendtec or KitchenAid), but a router and external HD should be fine (both should draw less power than a whole PC).