Exam Question

(a) Why a slow turning is fitted
A slow turning system is fitted in an engine air starting system to prevent potential damage caused by the accumulation of oil or water in the cylinders. During extended periods between engine operations, oil or water can leak into the cylinder and accumulate. If the engine is started with a full blast of starting air, the sudden pressure increase can cause hydraulic lock or mechanical damage to the engine.
The slow turning system ensures the engine rotates slowly before starting to identify and clear any such accumulation, protecting the engine from damage.
(b) The slow-turning system activates When the time interval between two engine operations exceeds the pre-set timer (usually 30 minutes).