If you amp is causing lights to dim you have an extreme power problem. If the lights are dimming significantly, the circuit is overloaded, the breaker should be tripping. The circuit is overloaded. There is an increased fire risk. Jerry
We do not know that for sure…
I used to turn on a table saw and the light in the garage would go out when it started up.
(Yeah the birds jumped off of the wire with hot feet.)
But if there is 30A on a 40A feed from the pole, and only 12A on a 15A breaker, it does not mean a fire is imminent. That is what people use breakers and fuses for.
It just means that the voltage sags.