I don't know if your model of iMac has a fuse built in to the power supply unit.
A power "trip" should not cause a problem, it's usually a power surge. Most electronic hardware has a safety margin, so that when power supply resumes suddenly, the 'spike', as it's called, doesn't cause damage. Surge protectors in household circuits, or in power boards so commonly used, will help to protect sensitive equipment, but that isn't going to help your present situation.
From what you've posted, I take it there's absolutely nothing happening when you press the power button - which means power isn't getting to where it's required. Any electronics technician can test the iMac psu to see if it's faulty or has failed, but the time it takes to open up the iMac is going be costly. Do you think you could open up the iMac? It's probably out of warranty now, judging by the info you're provided.
If you could put the opened-up iMac into a box, and took it to a technician, or to the Apple centre, they'd test the psu quite quickly.