Yes, the outlets in schools are on separate circuits. But if they are fed from the same 3-phase 120/208 panel as the kitchen equipment, there can be (and often were) issues. When you have the same problem in the same school on multiple occasions, with different photographers and different equipment, you see the patterns. This was a problem we found most often in schools built in the 1950s and 1960s.

Back when I was an AV producer, I had the same issues with multi-image slide projection equipment. My new production studio was in a yearbook printing company. The breaker sub panel feeding my area was fed from a larger panel in our book cover production department, where they had big embossing and foil stamping presses, both of which had thermostatic heaters AND big starting capacitors on their motors. Every time they would start a production run, my idling slide projectors connected to dissolve controllers would start randomly flashing their lamps and occasionally cycling. That was despite using 1800 Joule surge protectors on everything. After a couple of months of that nonsense, I called our building engineer into my office and asked him to take a look. He knew exactly what was happening, and had the electrician re-route the line coming to our area so that it had a more direct route to the transformers outside the building. Problem solved.

Murphy and his stupid law is lurking over your left shoulder...

Just because you're not paranoid doesn't mean he's not out to get you.

When I worked in the portrait lab, one of my assignments was to back up our photo consultants who had to contact customers and report on problems with their jobs. We had a running list of the top 50 failures, errors, and problems with jobs. In the film days, "problems with flash sync cables" was in the top 20. Joining that top 20 in the digital age were "Problems with flash memory media," and "Dirty power line in elementary school "cafetoria" We told photographers never to plug in their computers, cameras, and flash power packs anywhere near the wall between the kitchen and the cafeteria eating area. When those deep fat French fryers and ovens cycled on and off, the spikes flew...

I wired a radio station in my early 20s. The chief engineer taught me a very valuable lesson: When confronted with a choice of more or fewer connections in any circuit, it is always a SAFER bet that the circuit with fewer connections will be more reliable! Connectors, switches, and cables are the most likely failure points in electronics. Static electricity and AC power surges (spikes) come second.

I hate those damned adapters. I've been screwed twice when my kids loaned me SDXC Micro cards in an adapter. They corrupted one job and outright failed to mount properly on another. NEVER AGAIN.

I do not scrimp on cards. If a device CALLS for a Micro SD card, I'll use one, but I'll use the Micro SD slot on my high speed card reader, rather than put the card in an adapter to read it. I simply won't use a Micro SD in an SD adapter.