Smart plug for air conditioning unit

Question

I tried connecting my smart plug to my air conditioner, and the smart plug blew up.

I was wondering why it blew up and what kind of smart plug will work with my AC:

I used the Ardwolf Mini Smart Plug with the above air conditioner.

Answer 1

Your AC is rated at 4.9A, and the switch appears to be rated at 10A, so you've done nothing 'obviously' wrong (unless the device is marked explicitly not suitable for switching motors or inductive loads). However, to me the 10A current rating doesn't seem very believable. I'm not sure I'd want to trust that plug for even 5A.

The big problem is that your AC contains a large electric motor, and unless it is a modern 'invertor-control' device with variable power, the switch-on surge is likely to be fairly large. Not enough to blow a 10A fuse, but enough to potentially damage an electronic switch with a small design margin.

A switch rated at 16A, or even 20A is much more likely to be reliable in this context. I think you will struggle to find something like that though. It is much better to tap into the low-power control circuitry (presumably there is a remote switch or thermostat), or build a cascaded device with a larger switching relay as mentioned in this linked question.