NFPA 110-2025 Standard for Emergency and Standby Power Systems
Chapter 6: Transfer switch equipment – NFPA 110-2025 Standard for Emergency and Standby Power Systems

NFPA 110-2025 Standard for Emergency and Standby Power Systems 6.2.5-6.2.10: 6.2.5 to 6.2.10 ATS time delays

Time delays are required to stop nuisance starts on brief dips (start delay, typically about one second, short enough to meet the type); to sequence Level 1 load transfer once EPS voltage and frequency are proper; to delay retransfer so the primary source stabilises, automatically bypassed if the EPS fails (a manually initiated retransfer for planned interruption must keep that bypass); and to run the EPS unloaded for at least 5 minutes before shutdown, except small air-cooled sets of 15 kW or less. Delays may sit in the engine panel.

Maintained by Gerard Blokdyk

What else in your programme already covers this

This control maps to 5 controls across 4 other frameworks. If you already hold one of them, the evidence you collected for it is the starting point here rather than new work.

  • 9.45-9.53 Mains failure detection and automatic start and connection timing
  • 9.61-9.65 Mains return delay, load transfer method and cooling run-on
  • 2.7.9 2.7.9 Automatic changeover back to normal supply and ATS used as a main switch
  • 6.2.4.4-6.2.4.6 6.2.4.4 to 6.2.4.6 Manual operation, retransfer delay and test switch

Every mapping shown was judged rather than inferred from wording similarity, and the ones that failed review are published too. See the coverage reports and what was rejected.

Other controls in Chapter 6: Transfer switch equipment – NFPA 110-2025 Standard for Emergency and Standby Power Systems

Query this from an agent

The graph holds this control, the 5 it maps to, and the evidence behind each claim, over MCP and REST.