Hello! Not an EC, but know enough to be dangerous ... Which is why I don't touch things. That being said, an interesting occurrence at the office just now.
We are in a multi-tenant building, but electric is not divided out amongst tenants. We have a 3 phase feed into the building, some of the breakers are 120/240/480 and some are 277 and the other options. Lights are on the 277 panel. We have a transformer and each type of sub panel in our warehouse space, and in a mezzanine above our space.
About 15 minutes ago the anomaly occurred. Most (not all) of the lights in our suite started freaking out, flickering a bit and then went dim (these are all 2x4 LED tray lights) while some lights (hallway circuit, all 2x2 LED tray lights) started randomly flashing, looked like a scene from a sci fi space move were all the lights are flickering/flashing randomly.
A number (again, not all) of the office computer UPS started freaking out as well. Some of the smart ones showed incoming voltage of about 67 VAC.
We've had someone at our building installing vehicle chargers, but they are not here today. No noticeable issues, noises etc. coming from the panels that control these circuits in our suite. I know where the main electrical room is, and the main disconnect switch for the mezzanine equipment is (which I think then feeds the equipment in the warehouse). I killed the main disconnect for 10 seconds, and turned it back on, and everything went back to normal.
Is this a one off anomaly or is there something more urgent that I need to get an EC involved in?