CDA, this is from FM Data Sheet 4-9, Clean Agents. It parallels NFPA 2001 in most cases. I believe this is what you are after: 2.1.3.7.1 Provide a pre-discharge alarm and time delay sufficient to allow personnel evacuation prior to discharge. Limit the time delay to 30 seconds maximum after the appropriate detection signal(s) for system actuation have been received.