Mitsubishi Electric EA

What does Mitsubishi Electric EA mean?

EA, detected when power is turned on, indicates miswiring of the indoor/outdoor connecting wire or an excessive number of indoor units (four or more) connected. At startup the outdoor unit checks the connecting wiring and the connected indoor units; incorrect wiring or too many indoor units sets EA. This is an installation/wiring fault identified during the power-on check, not a refrigerant problem.

Symptoms

• EA shown at power-on
• System will not start after installation
• Fault appears right after wiring changes
• Outdoor unit rejects the connected configuration

Common causes

• Miswired indoor/outdoor connecting wires
• Too many indoor units connected (four or more)
• Wrong terminals used for the connecting wires
• Crossed connections between indoor units

Diagnostic steps

1. 01

   Power down all units

   Switch off the indoor and outdoor units before checking the wiring.

2. 02

   Verify the connecting wiring

   Confirm each indoor/outdoor connecting wire is on the correct terminals.

3. 03

   Count the indoor units

   Check that the number of connected indoor units is within the allowed limit.

4. 04

   Correct any miswiring

   Reterminate any crossed or misplaced connecting wires per the wiring diagram.

5. 05

   Restart and confirm

   Restore power and check whether EA clears at the next power-on.

When to call a professional

Call a qualified installer for EA, since correcting connecting-wire miswiring or an over-connected system must follow the wiring diagram and system limits. Verifying terminals and the indoor-unit count is mains-voltage work that requires the installation data. A professional should confirm the configuration and rewire it correctly before the system is energized again.