Carel MPXPRO
Modular controller for multiplexed display cases and cold rooms. It can run its own electronic expansion valve and link up to five secondary units on a local network.
What it is: Display case and cold room controller. Main/secondary (master/slave) network controller, with or without electronic expansion valve driver.
Key combo: Hold PRG/mute for 5 s for frequent (F) parameters. Hold PRG/mute + SET for 5 s, then enter the service password, for configuration and advanced parameters.
Carel MPXPRO error codes
| Code | Meaning | Likely cause | How to reset |
|---|---|---|---|
| rE | Control probe fault | The probe used for control has failed or is not configured | Automatic. Cooling runs on the duty-cycle setting (c4) meanwhile. |
| E1 | Probe S1 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E2 | Probe S2 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E3 | Probe S3 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E4 | Probe S4 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E5 | Probe S5 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E6 | Probe S6 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E7 | Probe S7 fault | Probe open, shorted, unplugged or wrong probe type set | Automatic once the probe reads normally. Check wiring and the probe-type parameters. |
| E8–E11 | Serial probe S8 to S11 not updated | Value sent over the network has stopped updating | Automatic. Check the network and the unit sending the value. |
| LO | Low temperature alarm | Alarm probe below the AL threshold for longer than Ad | Resets by itself once the cause clears. |
| HI | High temperature alarm | Alarm probe above the AH threshold for longer than Ad | Resets by itself once the cause clears. |
| LO2 | Second low temperature alarm | Below the AL2 threshold (probe set by AA2) | Resets by itself once the cause clears. |
| HI2 | Second high temperature alarm | Above the AH2 threshold (probe set by AA2) | Resets by itself once the cause clears. |
| IA | Immediate external alarm | Digital input set as immediate alarm has opened | Automatic. Cooling runs on duty setting A6. |
| dA | Delayed external alarm | Digital input set as delayed alarm stayed open past A7 | Automatic. Cooling runs on duty setting A6 if A7 is not 0. |
| dor | Door open too long | Door switch open past the door alarm delay | Resets by itself once the cause clears. |
| Etc | Real time clock fault | Clock not set or failed | Set the clock; replace the controller if it returns. |
| LSH | Low superheat | Expansion valve overfeeding (EEV models) | Automatic. Check superheat set point, probes and valve. |
| LSA | Low suction temperature | Suction temperature below its threshold too long (EEV models) | Automatic or manual depending on setting. |
| MOP | Maximum operating pressure | Evaporating pressure too high (EEV models) | Automatic. |
| LOP | Low evaporating temperature | Evaporating temperature too low (EEV models) | Automatic. |
| bLo | Valve blocked | Electronic valve appears stuck (EEV models) | Manual reset; disabled when P14 = 0. |
| Edc | Stepper driver communication error | Lost contact with the valve driver | Automatic. Check driver wiring. |
| HA | HACCP alarm type HA | High temperature during normal running for longer than the HACCP delay | Manual. Read and reset in the HACCP menu. |
| HF | HACCP alarm type HF | High temperature after a power cut | Manual. Read and reset in the HACCP menu. |
| MA | Lost contact with main controller (on a secondary) | Network cable or address problem | Automatic once communication returns. |
| u1… | Lost contact with secondary unit 1, 2, 3… (on the main) | Network cable or address problem | Automatic once communication returns. |
| n1… | Alarm on network unit 1, 2, 3… | A unit in the network has its own alarm | Check the unit named. |
| GPE | Custom gas parameter error | Custom refrigerant settings invalid | Automatic once corrected. |
| EFS | Stepper motor broken or not connected | Valve cable or motor fault | Automatic once fixed. |
| EE | Unit parameter memory error | Stored unit settings corrupted | Automatic if it clears; otherwise reload parameters or replace. |
| EF | Operating parameter memory error | Stored operating settings corrupted | Automatic if it clears; otherwise reload parameters. |
| up1… | Parameter upload error on unit 1, 2, 3… | Copy from main to a secondary failed | Repeat the copy. |
How to enter service / parameter mode
- Hold PRG/mute for more than 5 seconds. The first frequent (F) parameter shows. Any alarm buzzer is muted.
- For configuration (C) or advanced (A) parameters, hold PRG/mute and SET together for more than 5 seconds. A flashing 0 shows.
- Enter the service password with UP / DOWN and confirm with SET. The configuration and advanced levels have different passwords.
- Press PRG/mute to see the parameter categories, or scroll the list directly.
How to change and save a setting
- Scroll with UP or DOWN to the parameter.
- Press SET to show its value.
- Change it with UP or DOWN.
- Press SET to hold the new value and return to the code.
- Hold PRG/mute for 5 s to save and leave. If no key is pressed for a minute, the display returns to normal.
Other useful key presses
| Task | How |
|---|---|
| Change set point | Press SET until the value flashes, adjust, press SET to store. |
| Alarm log and HACCP | Reached from the keypad menus; HA / HF are reset from the HACCP menu. |
Notes
- Probe numbering on MPXPRO starts at E1 for S1. The valve alarms only apply to models with the built-in valve driver.
- Our list leaves out the generic-function and less common network codes; see the manual's alarm table for the full set.
For licensed technicians only. This equipment can involve mains voltage, high-voltage microwave circuits, gas and refrigerant. Isolate power (and gas) before opening panels, follow the manufacturer's manual and your local licensing rules (for example ARC refrigerant handling and electrical or gas licences). Wrong settings can spoil food or damage equipment. Check every value on the unit in front of you before changing it.
Based on: Carel MPXPRO user manual (+0300055EN rel. 1.7). Always check the manual for your exact model and software version.
ServiceModes is not affiliated with Carel or any other manufacturer. Written in our own words from the manufacturer's documentation.
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