The phase of the 220 mains. This varies with country but there's a 50-50 chance it's fine. If not try a plug that the breaker is on the other side of the main panel breaker box.
I'm trying to extend my cellular hotspot to an outlying building about 130-150' from my house. Thought of an extender setup of some kind, but someone suggested I look in to "powerline networking".
Not familiar with it, though reading about it, it sounds intriguing. My power comes from the pole to a main breaker box in my house. The power supply to the outbuilding is on that main line. From my main breaker box, the various circuits are distributed to my house circuits with a dedicated "branch" circuit going to a second breaker box with breakers/circuits for the outbuilding itself, and my pumphouse.
So, is that considered to be "all on the same circuit" and doable for this type of setup? If so, could I "hardwire" my cell modem to the house circuit using a powerline device plugged in to a house outlet and an ethernet cable from my cell hotspot, then use a second device (and ethernet cable) in my outbuilding plugged into an outlet and attached with it's own wireless access point/device to deliver wi-fi there?