Weird things happening

[Coppergobbler]

A couople of weeks ago a person reach out to me for some electrical rework at home and there's something weird I'm not sure why is happening. This guy has a split system ac in his office and everytime the outdoor unit turns on his computer monitor flickers. I checked the eveything beforehand and everything was in order. The numbers are optimal and everything works as it should. What would cause something like this? Could it be a bigger problem?

 

[Gallagher]

Split systems can cause flicker if the monitor is on the same circuit or phase, maybe move the computer to a different circuit or use a UPS with voltage regulation

 

[TriadsB]

What kind of surge protection or line conditioning does he have in place for his computer setup, could the AC be causing voltage dips or electrical noise on the circuit?

 

[Cityalight]

If everything checks out but the monitor still flickers when the AC kicks on, it sounds like classic dirty power or a grounding issue, it makes you wonder how many homes are running fine on paper but one surge away from frying gear