Dry Motoring Duty Cycle Limits #2 - 5 specify an ON time of?

Dry Motoring Duty Cycle Limits #2 - 5 specify an ON time of?

• A. 30 sec ON / 5 min OFF
• B. 90 sec ON / 5 min OFF
• C. 30 sec ON / 2 min OFF
• D. 60 sec ON / 5 min OFF

Answer: (A)

Dry motoring limits set how long you can run the engine on the starter without fuel and how long you must wait between cycles to cooling and protect components. For the Dry Motoring Duty Cycle Limits #2 through #5, the allowed on-time is 30 seconds, followed by a 5-minute off period. This brief 30-second on time minimizes heat buildup in the engine while still allowing a valid motoring check, and the 5-minute rest gives ample cooling for lubricants and hot parts, helping prevent overheating, oil degradation, and stress on bearings and seals. Extending the on-time or shortening the off-time would push temperatures and stresses beyond what these limits are designed to handle, so the other options don’t fit the intended safety margins.

Dry motoring limits set how long you can run the engine on the starter without fuel and how long you must wait between cycles to cooling and protect components. For the Dry Motoring Duty Cycle Limits #2 through #5, the allowed on-time is 30 seconds, followed by a 5-minute off period. This brief 30-second on time minimizes heat buildup in the engine while still allowing a valid motoring check, and the 5-minute rest gives ample cooling for lubricants and hot parts, helping prevent overheating, oil degradation, and stress on bearings and seals. Extending the on-time or shortening the off-time would push temperatures and stresses beyond what these limits are designed to handle, so the other options don’t fit the intended safety margins.