[Psycho0124]

Prolonged dimming (more than a quarter-half second) is almost a sure sign that the capacitor or compressor motor is beginning to fail. Be sure and investigate the cause if you see any extreme current draws from your a/c units. Near the end of it's life, I had a rather large window unit completely kill the breaker occasionally as it started to take large amounts raw current to get it to start up. It even managed to melt one of the internal wires (thermostat to selector switch I believe) as its last act of defiance before it was replaced. Good riddens to the ole fire hazard.

Split-second heavy draw on the line is perfectly normal for a big motor like an a/c compressor. Big induction motors are serious electron hogs on cold starts..