Error E51 — Power transistor anomaly (SRC50, 60 models)

What does E51 mean?

The power transistor primary current has exceeded its safe limit for 3 seconds, causing the compressor to stop. This indicates a problem with the power transistor assembly on the outdoor unit.

• Outdoor unit PCB anomaly
• Dust or foreign matter on the outdoor unit PCB
• Blown F2 fuse (250V, 20A) on the outdoor unit PCB

Click steps to track your progress.

1. 1

   Turn off the main power to the unit before performing any inspection.

2. 2

   Carefully check the soldered surfaces on the outdoor unit PCB for dust, dirt, or any foreign matter and gently remove it.

3. 3

   Inspect the F2 fuse (250V, 20A) on the outdoor unit PCB and replace it if it is found to be blown.

4. 4

   If the fuse is intact and no foreign matter is present, the outdoor unit PCB may be defective and require replacement by a qualified technician.