In the Know

Reduce Start Time for Your Emergency Power Supply

A quick start-up of your emergency power supply is crucial during a power failure. The National Fire Protection Agency requires your backup power supply to start up in 10 seconds or less for life-safety systems. Managers should conduct a regular system-level start time analysis to reduce start-up time. Caterpillar’s Amy Poparad offers additional tips for maintaining your backup power supply in her blog, “Reduce Start Time for Your Emergency Power Supply.


  • Low-voltage generators have a smaller rotational inertia that can reduce start times.
  • Critical loads should be less than the capacity of the smallest generator set for paralleled systems. Critical loads need to be energized as soon as the first breaker closes.
  • Decrease inertia during start-up by using remote radiators with electronic fans especially for oversized or high-voltage generators.


  • Control your system with the highest amount of accuracy by installing the latest version of your software. Outdated software can increase start time.
  • Ramp rate should match site and application needs. Reviewing and adjusting the ramp rate from the default value will improve start time. An increase in ramp rate will cause more black smoke during start-up.
  • Reduce the amount of time it takes for the generator to build rated voltage by regulating and decreasing the soft start feature in the digital voltage regulator (DVR).

Electric Starters & Batteries

  • Batteries should be fully charged on heavy-duty electric starters and back-up starters.
  • Add a second starter to decrease start-up time.
  • Set the electric starter and battery set to crank the engine for 10 seconds above 10 RPM.

Air Starter

  • Examine your engine model to determine the crank speed caused by your air starter.
  • Regulate air pressure by sizing air tanks and related lines to crank the engine for 10 seconds or more above 110 rpm.

Temperature Control

  • A water jacket heater can help maintain a minimum water temperature of 90°F.
  • Combustion air supply should be stored at 70°F.
  • A battery heater can help increase start-up time can help keep batteries warm if ambient temperatures are below freezing.

Fuel and Fluids

  • Avoid air intake and leaks by regularly changing fuel filters and monitoring the fuel system tubing.
  • Use continuous engine oil pre-lubrication (if available) to ensure smooth flow.

Read the blog.

San Diego
Steve Jamison

Power Systems Sales Manager

858.376.6821 office

858.688.0083 mobile


Cliff Yuen                

Power Systems Sales Manager                                  

808.676.0322 office

808.349.7767 mobile