What they do
Pressure and temperature sensors give the controller its readings. Solenoids operate valves for loading, unloading and drainage. A faulty or mismatched part leads to erratic behaviour or false alarms.
Identify the part
Collect:
- The machine make, model and serial number
- The part number and any markings on the sensor or solenoid
- Range, output signal type and connection for sensors
- Coil voltage and port size for solenoids
Diagnose before replacing
A false alarm may be a wiring, connector or controller problem, not just a failed sensor. We check readings against a known gauge and examine wiring and connectors.
Calibration and range
A transducer replaced with a different range or output gives wrong readings even if it fits. Confirm the range and signal type match the controller.
Before you order
Confirm the electrical specification and connector type.
Ask for the supply status of the item: whether it is genuine, OEM-approved or an alternative, and whether it is in stock or must be sourced.
Check the lead-time basis and the warranty terms that apply.
Frequently asked questions
Why does my compressor show a sensor fault?
The sensor, its wiring, a connector or the controller can all cause it. A systematic check finds the cause.
Can I use a sensor with a different range?
Not unless the controller is set up for it. Use the specified range and signal.
Do solenoid coils fail often?
They can fail through heat, moisture or voltage issues. Check the coil voltage and the operating environment.
Field guide
Sensors and solenoids: small parts, big consequences
Pressure transducers, temperature probes, pressure switches and solenoid valves tell the controller what is happening and carry out its decisions. A wrong reading can stop the machine, or worse, let it run outside safe limits. Replace them with the correct part and verify the reading afterwards.
| Part | Typical failure | Effect |
|---|---|---|
| Pressure transducer | Drift, water ingress, damaged cable | Wrong load and unload points, false high-pressure trips |
| Temperature probe | Open circuit, poor contact, wrong type fitted | False high-temperature trips, or no protection |
| Pressure switch | Contact wear, drifting set point | Short cycling on piston compressors, wrong pressure band |
| Loading solenoid | Burnt coil, sticking spool, blocked orifice | Machine will not load or will not unload |
| Blow-down solenoid | Leaking seat | Loss of pressure at stop, hard restart |
| Drain solenoid | Blocked strainer, burnt coil | Water carried into the system, or air wasted |
Getting the right replacement
- Match range, signal type and connection: a 0 to 16 bar 4 to 20 mA transducer is not interchangeable with a 0 to 10 V or different range unit.
- Match coil voltage (AC or DC), port size, pressure rating and normally open or normally closed function for solenoids.
- Use the correct probe type for temperature sensors; the controller is set for one type.
- After fitting, compare the controller reading with a calibrated gauge or thermometer and test the trip function.
What to send for a quotation
- Compressor make, model and serial number.
- Photo of the part showing its label, connector and fittings.
- Controller reading and the fault text.
- Coil voltage for solenoids.
Send it through find my part or the spare parts enquiry, or call +91 99590 60718 or +91 92468 88812.