The answer to 'why is my smoke detector circuit overload' is that the smoke detector circuit is drawing more electrical current than it is designed to handle. This can be caused by a number of factors, including a malfunctioning smoke detector, a wiring issue, or a problem with the electrical panel.
Some common symptoms of a smoke detector circuit overload include flickering lights, circuit breakers tripping, or the smoke detectors not functioning properly. To troubleshoot the issue, you'll need to inspect the smoke detectors, check the wiring, and potentially test the circuit breaker or electrical panel.