Mitsubishi Electric UP

What does Mitsubishi Electric UP mean?

The compressor was interrupted on overcurrent and the unit shows UP on a blinking display. The control trips when compressor current exceeds the safe limit during running, protecting the motor and inverter. Unlike a locked-rotor trip, this reflects high current under load, which can come from high pressures, supply problems, or a developing compressor or inverter fault.

Symptoms

• UP shown on a blinking display
• Compressor stops on the protection device
• Trips under load or in hot conditions
• Reduced heating or cooling before shutdown

Common causes

• High condensing pressure raising compressor current
• Restricted airflow or dirty outdoor coil
• Abnormal supply voltage
• Compressor motor or inverter fault
• Refrigerant overcharge

Diagnostic steps

1. 01

   Power down and cool off

   Turn the unit off and let it cool before restarting.

2. 02

   Clean the outdoor coil

   Clear debris and clean the coil to lower high-side pressure and current.

3. 03

   Confirm the supply

   Check that the outdoor unit has correct, stable voltage.

4. 04

   Attempt one reset

   Restore power and note whether UP returns quickly under load.

5. 05

   Stop repeated trips

   If UP persists, leave the unit off and arrange service.

When to call a professional

Call a licensed technician if UP recurs after airflow is restored, since persistent overcurrent can indicate high pressures, a charge problem, or a compressor or inverter fault. Diagnosing these requires gauges, electrical meters, and certification. A qualified professional should measure current and pressures before the unit is returned to service.