Rule 701. Section 3-1.1.1 of the standard is amended, section 3-2.3 of the standard is deleted, and section 3-5is added to the standard, to read as follows:
3-1.1.1. For electrically powered detectors, an AC primary power source shall be utilized in all new and existing construction.
3-2.3. Deleted.
3-5. A secondary source of power is required and it shall be of sufficient capacity to operate the system for 24 hours and thereafter to sound alarm devices for not less than 4 minutes. A distinctive trouble signal shall be given before the secondary power supply is incapable of operating the equipment for alarm purposes.
Mich. Admin. Code R. 400.18701