I’d like to use a smart plug to control an ungrounded lamp plugged into an ungrounded extension cord. The problem is that any smart plugs I can find have a ground prong, which will get in the way. I could put a smart plug between the wall outlet and the extension cord, but then the plug would control all of the extension cord’s receptacles, and I might want to use something else plugged into it while the lamp is off. I’d prefer to plug the lamp into the smart plug and plug that into the extension cord.
Nobody’s gonna bother selling a two-prong smart plug because ungrounded wall outlets are very rare this century and you can always plug an ungrounded two-prong device into a three-prong outlet. My use case is fairly marginal.
The easiest answer here, obviously, is “don’t do that”. Anyways…
I already use IKEA TRETAKT smart plugs in a couple places and I figured it was pretty likely that their smart circuitry isn’t grounded. If I could confirm that, I could safely modify one for ungrounded use. I couldn’t find a teardown online for the North American version of the plug, so I picked up a new one and cracked it open.
It was immediately apparent that the ground prong is completely isolated from the the smart plug circuitry. What’s more, it can be easily – and non-destructively – removed, to make a two-prong smart plug.
Here are a few photos of the disassembled TRETAKT, in case they’re useful to anyone else.
