46 C.F.R. § 112.25-5 Failure of power from the normal source.
Title 46 - Shipping
If there is a reduction of potential of the normal source by 15 to 40 percent, the diesel engine or gas turbine driving the final emergency power source must start automatically with no load on the emergency power source.
Title 46: Shipping
PART 112—EMERGENCY LIGHTING AND POWER SYSTEMS
Subpart 112.25—Emergency Systems Having an Automatic Starting Diesel Engine or Gas Turbine Driven Emergency Power Source as the Sole Emergency Power Source
§ 112.25-5 Failure of power from the normal source.

