Error Code in Mr Cool Air Conditioners:

Now, we will explore the meaning and solutions for fault codes related to temperature sensors in Mr Cool air conditioners. These codes will be categorized based on the location of each sensor. First, we’ll explain their meanings, and then we’ll proceed with troubleshooting.

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Sensor-Related Fault Codes

1. Indoor Unit Well or Pipe Sensor
   • This sensor monitors the evaporator coil temperature during cooling mode.
   • Fault codes: E5, EC56, E61
2. Indoor Air Temperature Sensor
   • Located in the indoor unit, this sensor monitors the room temperature.
   • Fault codes: E4, EH60
3. Outdoor Unit Coil Temperature Sensor
   • This sensor monitors the condenser coil temperature during cooling mode.
   • Fault code: EC 52
4. Outdoor Ambient Temperature Sensor
   • This sensor measures the external ambient temperature.
   • Fault code: EC 53
5. Compressor Discharge Temperature Sensor
   • Monitors the temperature at the compressor’s discharge line.
   • Fault code: EC 54

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Steps for Troubleshooting

1. Restart the Unit
   • Turn off the air conditioner and unplug it for several minutes.
   • Power it back on to see if the issue persists.
2. Locate the Temperature Sensor
   • Based on the error code, identify the affected temperature sensor.
   • Verify if the sensor is correctly positioned.
3. Inspect the Sensor Connections
   • Check the sensor’s cable and its connection to the electronic control board.
   • Clean the connections if necessary.
4. Test the Sensor’s Electrical Resistance
   • Turn off the unit and disconnect the temperature sensor.
   • Use a multimeter set to the kilohm scale to measure the sensor’s resistance.
5. Interpret the Resistance Measurement
   • The resistance value should not be zero or infinite, regardless of the orientation of the multimeter probes.
6. Compare with Manufacturer’s Specifications
   • If you have the resistance chart for the unit, compare the measured value to the chart to rule out sensor failure.
7. Inspect the Electronic Control Board
   • If the sensor checks out, the issue might be with the control board.
   • Conduct a visual inspection for anomalies. Test and measure components near the sensor’s connection port.
8. Replace Components if Necessary
   • If the fault remains unresolved, replace the sensor with one of the same specifications.
   • If the problem persists, replace the electronic control board associated with the affected sensor.

Error Code in Mr Cool Air Conditioners: EL 0C

The EL 0C error code in Mr Cool air conditioners is related to a potential refrigerant gas leak in the system. This code is triggered when the indoor unit’s electronic board detects an anomaly in the evaporator coil temperature during the initial minutes of operation.

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How the Problem is Detected

When the unit is turned on, the electronic board sets the initial temperature of the evaporator coil based on readings from the indoor unit’s temperature sensor.

• During the first 5 minutes of operation, this sensor monitors whether the measured temperature decreases by at least 1°C (1.8°F) below the initial temperature continuously, provided the compressor frequency is above 50 Hz.
• If this condition is not met within a specified time, the system displays the LC error code on the LED and shuts down automatically.

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Steps to Resolve the EL0C Error Code

1. Restart the System
   • Turn off the air conditioner and unplug it for several minutes.
   • Turn it back on and check if the issue persists.
2. Check for Cold Air Output
   • Before the LC error activates, place your hands in front of the indoor air outlet.
   • If there is no cold air:
     a. Check if the outdoor unit’s compressor is running.
     b. Inspect pipes and connections for oil stains, which are common indicators of refrigerant leaks.
   • If cold air is present:
     The issue may be related to the temperature sensor, its connections, or the indoor unit’s electronic board.
3. Measure the Unit’s Electrical Consumption
   • Use a clamp ammeter to measure the current. A lower-than-normal reading may indicate a refrigerant shortage.
4. Test the Temperature Sensor
   • Disconnect the sensor and use a multimeter to measure its resistance on the kilo-ohm scale.
   • The reading should not be 0 or infinite and must match the manufacturer’s specifications.
5. Inspect for System Blockages
   • Check the capillary tube while the unit is running.
   • If the capillary is cold or frozen, it indicates an internal blockage that needs attention.
6. Examine the Indoor Electronic Board
   • If there are no leaks or blockages, visually inspect the indoor electronic board for faults. Replace it if necessary.

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Procedure to Solve E1 and EL01 Error Codes in Mr Cool Air Conditioners

The E1 and EL01 error codes typically indicate a communication failure between the indoor and outdoor units. Follow these steps to diagnose and resolve the issue:

1. Restart the Unit
   • Turn off and unplug the air conditioner.
   • Wait a few minutes before turning it back on.
   • Check if the error code disappears.
2. Check Power Supply Voltage
   • Measure the electrical voltage using a multimeter.
   • If the voltage is unstable, consider installing a voltage stabilizer.
3. Inspect Connections
   • Perform a visual inspection of the connections between the indoor and outdoor units.
   • Ensure cables are properly connected to the L1 and L2 terminals that supply AC power.
4. Measure Signal Voltage
   • Follow these steps:
     a. Multimeter Configuration: Set the multimeter to DC voltage mode.
     b. Locate Ports: On the outdoor unit, measure between port 2 (neutral or L2) and port 3 (signal). The signal cable may be marked as “S” or “3” depending on the model.
     c. Connect the Multimeter:
     • Red probe: Connect to the signal cable (port 3 or “S”).
     • Black probe: Connect to the neutral port (L2 or port 2).
       d. Interpret Results:
     • If the unit is operating correctly, the voltage will fluctuate between positive and negative values.
     • A fixed voltage indicates a fault in the indoor unit.
     • A constant positive voltage indicates an issue with the outdoor unit.
5. Inspect the PFC Circuit
   • Check the PFC circuit in the outdoor unit:
     • Measure the voltage output from the rectifier bridge.
     • Inspect the fast recovery diode and IGBT transistor for short circuits or damage.
     • Measure the DC voltage supplied to the intelligent power module (IPM).
6. Inspect the Reactor
   • Disconnect the outdoor unit’s reactor.
   • Use a multimeter set to continuity or resistance mode.
   • Normal resistance should be close to 0 ohms. If not, the reactor may be faulty.
7. Examine the Communication Circuit
   • Locate the communication circuit in the outdoor unit, which includes a pair of optocouplers.
   • Inspect resistors, capacitors, and diodes for signs of damage or wear.