Pressure switch vs control

Pressure switch vs control: a pressure switch is a basic two-state device — contact closes below cut-in, opens above cut-out — used to start and stop simple compressors. A pressure controller is an electronic device, typically microprocessor-based, that runs the load/unload cycle, manages alarms, logs runtime, and (on larger systems) sequences multiple compressors.

What it is

Pressure switches are everywhere on small piston compressors: a Bourdon tube or diaphragm sensing element flips a snap-action contact at cut-in and cut-out. They are cheap (often under $50), robust, and have no logic. Pressure controllers are full HMI-equipped units (Atlas Elektronikon, Ingersoll Rand Xe, Kaeser Sigma Control, generic PLC-based platforms) that manage compressor load curves, schedule purges, sequence multiple machines, and feed data to plant SCADA.

Why it matters

For a 5 HP piston filling a 60-gallon tank in a one-bay shop, a pressure switch is exactly right. For a 100 HP rotary screw in a 24/7 plant, a real controller is essential — it manages safe load/unload, blow-down timing, sequencing with backup machines, and the diagnostics that prevent catastrophic failure. Trying to run an industrial compressor with a pressure switch loses 10-15 percent of available efficiency.

How it is used in our catalog

Light-duty piston compressors ship with pressure switches. Modern rotary screw compressors ship with manufacturer controllers. The installer directory covers controller upgrades and aftermarket sequencing for multi-compressor plants.

Common questions

Can I upgrade a pressure-switch compressor to a real controller?

On rotary screw machines, often yes, through manufacturer or aftermarket retrofits. On piston compressors, rarely worth the cost.

What does a controller do that a switch cannot?

Adjustable load/unload bands, runtime logging, alarm thresholds (temperature, oil pressure, filter differential), networked sequencing across multiple compressors, energy reporting, and remote access.