by Fred Theilig – @fmtheilig
A little over four years ago I purchased a power strip. It had USB-A ports for charging and was flanged for easily securing it to my desk. It was part of my work from home setup and served me well over the years. Several months back my work laptop was upgraded, and the docking station (or port replicator – whatever we call them these days) was swapped out. A few weeks later, the new dock failed. Doing my routine investigation, I tested the power strip and discovered that the hot and neutral were swapped. Upon learning this, tech support told me to never plug any company owned asset into that strip.
On a North American three prong electrical plug, the flat prongs are wired neutral (the slightly larger one) and hot, while the round ground wire completes the surprised pikachu face. I’m in no way qualified to explain the details of this arrangement, but I know that it is specified in building code. I have a tool that quickly and reliably tests the outlet.
So, did this power strip kill my dock? I’m skeptical. My understanding is that the primary risk was personal safety were I to work on the equipment while it was plugged in (not that I have ever done this). For instance, I have a desktop case opened with the chassis exposed. Instead of the physical switch breaking the connection to hot, it’s breaking neutral and hot is still live over the neutral pathway. I could be standing on earth ground or leaning on the chassis, completing a very nasty circuit.
Another possible problem is if the power strip switch brakes the neutral line rather than hot. Here the device will appear off, but shorting hot and ground will result in a surprise. This was not the case for me.
Again, I am no electrician, but if there were a power spike, and it came over the neutral line, maybe the electronics could be damaged. Theoretically. I contacted the supplier, and even though the device was four years old, they reimbursed me. Didn’t need proof nor the bad unit returned. That reversed my anger right quick.
Testing wall and power strip outlets is an easy way to verify things are wired correctly, and I recommend everyone who works with computing equipment purchase an outlet tester. While I can’t quantify the risk, I have it on good authority that it’s there.