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Error code reference

Mitsubishi Air Conditioner Error Code CP

Parameter copy warning

Mitsubishi codesMitsubishi air conditioner codes

Parameter copy warning - appears when parameter copy performed between different-capacity inverter models.

First step from the service manual

Reset required parameters (Pr.9, Pr.30, Pr.51, etc.) and set Pr.989 Parameter copy alarm release.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What CP means on a Mitsubishi air conditioner

The CP warning on a Mitsubishi inverter-driven air conditioner indicates a parameter copy mismatch. This warning is triggered when parameter data is copied from one inverter unit to another inverter of a different capacity rating. Mitsubishi inverter drives use capacity-specific parameter sets, and when data from one capacity model is transferred to a non-matching unit, the system flags the incompatibility to prevent potentially unsafe or incorrect operation.

The parameter copy function allows technicians to duplicate drive settings from one inverter to another, which is useful for maintaining consistent configurations across identical units. However, certain parameters are capacity-dependent, including motor protection settings, current limits, and torque characteristics. When the source and destination inverters differ in capacity, these capacity-specific values become invalid for the new unit. The CP warning does not indicate a hardware failure, but it does mean the inverter will not operate normally until the conflict is resolved.

Resolving the CP warning requires two steps. First, the technician must manually reset the parameters that are specific to the destination inverter's capacity. These include, at minimum, Pr.9 (electronic thermal O/L relay), Pr.30 (regenerative function selection), and Pr.51 (second electronic thermal O/L relay), along with any other capacity-specific parameters flagged by the system. After correcting those values, the technician must set Pr.989 to the parameter copy alarm release value to clear the CP warning and restore normal operation.

Source: manufacturer service documentation.

Common causes of CP

  1. 01

    Parameter copy performed between mismatched inverter capacities

    Wiring / connection

    The most direct cause of the CP warning is using the parameter copy function to transfer settings from an inverter of one capacity rating to a unit of a different capacity rating. The destination unit detects the mismatch and raises the warning before allowing operation.

  2. 02

    Replacement inverter installed with copied settings from original unit

    Wiring / connection

    When an inverter board is replaced and the original unit's parameters are copied to the new board, a CP warning will appear if the replacement inverter has a different capacity specification than the original, even if the physical installation appears correct.

  3. 03

    Incorrect parameter reset after copy operation

    Wiring / connection

    If a parameter copy was performed and some capacity-specific parameters such as Pr.9, Pr.30, or Pr.51 were not corrected afterward, the system will continue to show the CP warning. The Pr.989 alarm release step may also have been skipped.

  4. 04

    Programming error during commissioning or setup

    Wiring / connection

    During initial commissioning or setup of multiple units, a technician may accidentally apply parameter data from the wrong unit profile, particularly when programming several inverters in sequence.

See the test procedure for each cause

Frequently asked questions about CP

What does CP mean on a Mitsubishi air_conditioner?
The CP code on a Mitsubishi inverter air conditioner is a parameter copy warning. It appears when parameter data has been copied from one inverter unit to another unit with a different capacity rating. The system flags this mismatch to prevent the inverter from running on incorrect settings. It is a warning, not a hardware fault, and can be resolved through parameter correction.
How do I fix the CP warning on my Mitsubishi inverter unit?
To clear the CP warning, a technician must first identify and reset the capacity-specific parameters that were incorrectly copied. At minimum, parameters Pr.9, Pr.30, and Pr.51 should be reviewed and set to values appropriate for the destination inverter's capacity. Once those parameters are corrected, setting Pr.989 to the parameter copy alarm release value will clear the CP warning and allow normal operation to resume.
Is the CP warning on a Mitsubishi air conditioner a safety risk?
The CP warning is a protective measure built into the inverter to prevent operation under mismatched settings, which could cause improper motor protection thresholds or incorrect current limiting. Running the system with unresolved capacity-mismatched parameters could lead to inadequate motor protection or performance issues. The system intentionally restricts operation until the parameters are corrected, so the warning itself is the safety mechanism working as intended.
Will resetting the unit clear the CP warning?
A simple power reset will not clear the CP warning on a Mitsubishi inverter unit. The warning is tied to specific stored parameter values that remain in memory even after a power cycle. Clearing it requires manually correcting the affected parameters, including Pr.9, Pr.30, Pr.51, and others as applicable, and then setting Pr.989 to the alarm release value. Until those steps are completed, the warning will persist.
How much does it cost to fix a CP warning on a Mitsubishi air conditioner?
Because the CP warning typically requires only a parameter programming correction rather than parts replacement, repair costs are primarily labor-based. A technician service visit to diagnose and correct the parameters could range from roughly $80 to $200 depending on your location and the technician's rates. If the CP warning resulted from a failed or incorrect inverter replacement and the correct replacement inverter is also needed, total costs would be higher, generally in the range of $300 to $800 or more depending on the unit capacity.

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