Silko Pr1

What does Silko Pr1 mean?

Pr1 is the chamber sensor (probe) error on Silko refrigerated units. The controller cannot read a valid signal from the cabinet/chamber temperature sensor, so it falls back to a protective control mode: the compressor runs on a fixed on/off duty cycle of about 10 minutes, defrosting is not activated, and the alarm relay is activated if parameter u1=3. The cabinet temperature is no longer regulated by a real reading.

Symptoms

• "Pr1" appears on the controller display.
• Compressor runs on a fixed timed on/off cycle (about 10 minutes) instead of by temperature.
• Defrosting does not activate while the fault is present.
• Cabinet temperature drifts because it is no longer controlled by the chamber sensor.

Common causes

• Wrong sensor type configured for the chamber probe.
• Chamber sensor damaged or out of range.
• Faulty instrument-to-sensor connection.
• Chamber temperature outside the sensor's valid measuring range.

Diagnostic steps

1. 01

   Verify the sensor type

   Confirm the chamber sensor configured in the controller matches the sensor actually fitted, as the manual lists an incorrect sensor type as a cause.

2. 02

   Check the sensor integrity

   Inspect the chamber probe for physical damage and verify it is not open or shorted.

3. 03

   Check the instrument-sensor connection

   Confirm the connection between the controller and the chamber sensor is secure and free of corrosion or breaks.

4. 04

   Verify the chamber temperature

   Check that the actual chamber temperature is within the sensor's valid range so the reading is not rejected as out of bounds.

5. 05

   Call for replacement if unresolved

   If functioning cannot be restored by the above checks, the manual directs you to call a technical support centre to perform replacement and regulations.

When to call a professional

Operators can verify the sensor connection and confirm the cabinet is not loaded beyond its range, but the manual instructs that if normal operation cannot be restored you should call an authorised technical support centre to replace the sensor and reset the controller settings. Disconnect the appliance from power before any internal access, especially on R290 units.