PC49 Compressor over-current

What the control is telling you

The compressor drew more current than allowed.

Applies to: DLCM(R/H)B multi-zone outdoor units with DLFSHBH high wall indoor units (Midea, Carrier, Viessmann)

Likely causes

• High load / restriction
• Poor outdoor airflow
• Bad compressor or PCB

Test and repair steps

1. Safety kill power at the disconnect and wait for the inverter capacitors to discharge before touching boards or wiring.
2. Measure the input current on the supply wire. Limits: 15 A on 18K; 18.5 A on 27K and 18K high heat; 22.5 A on 36K and 27K high heat; 28 A on 48K and 36K high heat.
3. Outdoor air above 122 F (50 C) = outside the range, shut it down.
4. Check outdoor airflow and clean the coil.
5. Check for a refrigerant restriction. If blocked: recover the charge, blow the lines through with nitrogen, evacuate and recharge.
6. If none of the above, replace the outdoor main board (or the electric control box) and retest.

Models that show this code

12 models in Carrier DLCM(R/H)B multi-zone outdoor, Carrier DLFSHB high wall indoor

Other codes on the same units

• PC43 Compressor phase loss
• PC44 Zero speed protection
• PC45 Compressor drive chip (IR / 341 PWM) failure
• PC46 Compressor speed out of control
• PCA1 Refrigerant pipe condensation protection
• PH09 Anti-cold-air in heating
• PH90 Evaporator coil too hot
• PH91 Evaporator coil too cold