Optionally, the compressor geometry can be set up under the main annunciator setup, then “Inputs Setup”, then “Compressor Geometry / Performance”.
Compressor Geometry Setup
On the left side of the page, the piston sizes can be entered to enable rod load monitoring. For each stage of the compressor enter a head end and crank end area for the compressor piston. If valid, the annunciator will measure the rod load of each stage over time, in lbf, during tension and compression. High rod loads or unbalanced loads can lead to premature wear or failure of compressor parts. A high alarm can be added to each stage to shut down the engine if a load is exceeded for that stage.
The right side of the page allows an alarm to be added for exceeding a compression ratio. Each stage’s compressor ratio will automatically be logged, and an alarm can be added here to shut down the engine if a stage exceeds the given ratio. Generally a ratio above around 4.5 indicates a design issue with the application.
Note: The calculation is only valid for double-acting cylinders