This paper presents the design and development of an intelligent fire safety-management system (FSMS) for electrical fire precaution and early warning. The system is based on an ac/dc power-line communication network, and consists of three elements: ac electric energy meter with a smart breaker, fire alarm concentrator, and de-powered smoke sensors. The FSMS operates according to a proactive precaution and early discovery scheme. By this scheme, the system continuously monitors the energy information and line losses to identify potential electrical fires, and can shut off illegal electrical usage. Furthermore, the scheme exploits the electricity index to adjust a dynamic queued duration for averaging the smoke density. In case of an electrical fire, it can therefore shorten the fire alarm delay, while still keeping a low false alarm rate. The FSMS has been tested at NCTU University, and some experimental results are included to demonstrate the feasibility of the FSMS system.