Just some clarification on terminology for those who may stumble upon this topic in the future. I know people often generalize because its the first thing that comes to mind but in this case its important to call out the distinctions. ESD (Electro Static Discharge) is normally associated with a person who builds up a positive charge and then relays the same to an object upon being touched.
Think door knob . . .
ESD is a huge problem when repairing any sensitive electronics and hence why ESD mats, wrist bands, and equipment is properly grounded.
ESD is not the problem here as it is more likely a surge event whether it be from interior generated (micro surges) or more likely external in nature. As others noted any time there is a voltage difference (potential) in ground reference anything can happen.
Keep in mind what I stressed about slow creeping voltage whether it be rise vs sag.
If there is something wrong with the incoming power supply to the home such as a creeping voltage rise (above 130 VAC) this condition will release the magic smoke out of the box. Again, an extended voltage sag (brown out) below 90 VAC will also cause things to go poof!
Why???
Because lots of electronics now use buck / boost electronics to maintain a steady flow of power to the appliance. This loosely speaking (buffered) power allows a device to ride out variations of voltage swings without issue. One only needs to look at the specifications of any security camera whether its for POE vs 12 VDC. The spec literally says X system will operate from 38 - 5X volts POE vs 12 VDC is 25% swing either way!
That's literally 9 volts ~ 15 volts on a 12 VDC system . . .
That is awesome in terms of operating voltage and allows that device to run fine in varied electrical conditions. But this loose range injects something that many people fail to understand when ever I note about:
When voltage drops current rises . . .
This statement always confuses people because their only reference is basic Ohms law and that only applies to simple resistive circuits. Because in those simple resistive circuits that doesn't happen. When voltage drops so does current and matches in lock step. In a complex highly regulated PSU like a camera the system is designed to accept a INPUT power of varied voltages. But at all times has a highly regulated 3.3, 5.0, 12 VDC rails kept at constant states to insure high reliability and operations.
Hence when voltage sags (brown out) that highly regulated PSU will continue to draw more current to satisfy its operations but in doing so it will burn out whatever.
The above scenario always explains why if a system that incorporates power protection like HRC fuses, MOV, PTC, Zener, etc why they never blow. Again, all of the above are designed to react to sudden quick surges but are not designed for slow rise (creeping voltage) whether it be AC vs DC. As the OP showed there were PTC's and possible MOV's in one photo that didn't break open from a visual perspective.
Regardless, in the ideal world everything should be at the same potential and referenced to a single point (Earth) ground from the incoming utility. As noted in the past one problem I've seen in commercial installs like the OP is where the building uses some kind of metal cladding which isn't at the same ground potential. In those cases it caused anything from a ground loop and you would see lines on the video to popping noises in the audio.
The easiest thing to do as counter to what many would think to do is to
Decouple the camera from the metal frame. This is normally done by using a plastic junction box that also uses a foam insulator. Now, the camera uses just the ground coming from the power wire whether it be from POE / 12 VDC.
None of this is rocket science but does take some common sense to understand, identify, and implement when needed.
As noted early on before the POCO comes on site you can double check all of the wires going to any breaker is tight. Verify all ground and neutral bars are corrosion free and also tight in the service panel. Go to main water main and if your location bonds to the incoming water source that this bond is secure and corrosion free. Move inspect all outlets and switches in the home and confirm all wiring is tight and secure to their respective point of use.
This is also a good time to walk around and inspect every piece of electronics in the home. Besides the obvious visual inspection take any small electronics and pick it up and smell it. Do a rattle test and if you hear things bouncing around its going to be a piece of electronic component that literally just blew up!
Why is doing this basic step important???
Because these same electronics are literally a fire hazard waiting to explode and light on fire. They also are a direct point of micro surges and noise related issues from RFI / EFI. In North America all new houses incorporate AFCI (Arc Fault Circuit Interrupters). Their only goal in life is to detect micro arcs happening in the walls in the buildings envelope.
This is what's happening when you don't check every piece of electronics after a huge lightning strike that was proven to damage one major appliance. If it took out a random piece of appliance like a stove, fridge, microwave, dishwasher, washer, dryer. What are the odds it didn't impact a cheap radio, TV, boom box, name anything that's electronic in nature!
Nine times out of ten you will quickly find visually or through smell something else was damaged from that first strike. Those who live in Lightning Alley know this information to be true and expect to find something dead or damaged.
As an aside I've been heavily involved in energy management & energy control for more than 30 years. In a past life this was major part of my profession and now is a big hobby in my personal life. I have many power quality monitors and energy management systems that track and monitor every aspect of my homes incoming power. Below is a very old image capture that shows one of the systems being fine tuned and calibrated to the Nth degree.
The system isn't normally set to capture
Normal line voltage conditions but I wanted to see what the system would capture while my back up power systems were being deployed. As seen here the system captured voltage sags, frequency drifts, voltage rises, and the duration of each. Having such
tools in place allows factual information to be obtained and relayed to the POCO if and when required. There's no guessing, there's no I dunno, there's only the material data to provide and for them to resolve!
