News & Insights
Atlas Copco 2204103900 Pressure Sensor: Symptoms, Fitment and Cross-References
How to spot a failing 2204103900 press sensor on an Atlas Copco compressor, confirm fitment by machine serial number, and cross-reference the Sensata 81CP61-01 element before ordering.
The 2204103900 press sensor is one of the parts that stops an Atlas Copco compressor from running properly without always showing an obvious mechanical fault. This guide explains what the sensor does, which symptoms usually point to it, how to confirm the right part for your machine, and how to cross-reference it before you order.
What the 2204103900 sensor does
The sensor measures pressure in the compressor air system and sends an electrical signal to the controller. The controller uses that signal for loading and unloading, pressure regulation, and protection against over-pressure.
The sensor element is a Sensata 81CP61-01, fitted in an Atlas Copco housing with the 2204103900 part number. Because the controller trusts this signal, a sensor that drifts or fails does not only give a wrong reading; it can change how the whole machine behaves.
Symptoms that usually point to the sensor
These symptoms are common on machines with a failing press sensor, but none of them is proof on its own. Always check the wiring, the connector and the actual system pressure before replacing the part.
- The pressure shown on the controller does not match a known-good gauge on the same line.
- The reading jumps, freezes at a fixed value, or stays at zero while the machine is clearly building pressure.
- The compressor loads and unloads at the wrong pressure, or keeps running unloaded.
- The machine trips or shuts down for a pressure-related reason even though the system pressure is normal.
- The reading is stable when the machine is cold and drifts once it reaches operating temperature.
How to confirm the correct part for your machine
Atlas Copco builds several versions of the same compressor family, and the sensor fitted depends on the model, the serial number and the build year. The safest sequence is:
- Read the part number on the label of the old sensor.
- Write down the machine type and serial number from the compressor nameplate.
- Photograph the old sensor, including the connector and thread.
- Send all three to your supplier and ask them to confirm the part against your serial number.
If the label is unreadable, the machine serial number is the reliable starting point, because the parts list is organised by serial number range.
Cross-references and where the same number appears
2204103900 is also listed in parts catalogues for other compressor brands in the same group, and the Sensata 81CP61-01 element appears under several descriptions such as press sensor, pressure sensor and pressure transducer. When you search for a replacement, search both the number and the description, and confirm the thread, connector type and pressure range match the part you are removing.
A part that looks identical but has a different pressure range will fit mechanically and still give wrong readings, so the number check matters more than the appearance.
What to check before you replace the sensor
- Wiring and connector: a damaged plug or a broken wire gives the same symptoms as a failed sensor.
- Contamination: oil or water in the sensing port can block the pressure signal.
- Controller settings: confirm the pressure setpoints have not been changed by mistake.
- Actual pressure: compare with a calibrated gauge at the same tapping point.
If the wiring and the actual pressure are correct and the reading is still wrong, replacing the sensor is the reasonable next step.
Ordering the 2204103900 press sensor
We supply the 2204103900 press sensor (Sensata 81CP61-01) for Atlas Copco compressors, together with filters, separators, valves and other genuine spare parts. Send the machine model, serial number, the quantity you need and the delivery country, and we will confirm fitment, price and lead time before you order.
Use the Request a Quote button on this page or contact us directly by WhatsApp or email.