A cascade needs sensible pressure bands
As pressure falls, more compressors are added in sequence. Poorly overlapping bands can cause simultaneous responses or long unloaded operation. An excessively wide cascade raises the upper pressure. Correct spacing is not a universal number: it depends on demand dynamics, network volume and the controllers.
A common pressure signal is not enough without machine data
A master system can manage base load, machine staging, operating-hour balancing and the regulating compressor. It must respect starting and operating limits, communication and fault behaviour. When combined with VSD it is important that the individual control loops do not work against each other.
What to check in practice
- Map the compressors, available communication interfaces and performance characteristics.
- Measure pressure and demand, including breaks and failure scenarios.
- Define the backup mode and how the achieved benefit will be verified.
Example scenario
Two machines each deliver 5 m³/min, while the operation needs 6 m³/min. Poor control can cause both to unload frequently. A sound design assesses base and supplementary delivery, storage and input power. Simply balancing operating hours does not guarantee the lowest consumption.
What to watch out for
- Treating visualisation as active control.
- Using the same pressure spacing for every station.
- Optimising only the sequence without knowing the demand profile.
Must all compressors be the same brand?
Not always. What matters is technical interface compatibility, permitted control signals and safe retention of each machine's own protective functions. The specific connection must be verified against the documentation for each machine.