warning Upgraded

Error Code CPF09

Heat Sink SR Open / Low Operating Temperature alarm — the operating temperature has fallen below 0°C (32°F).

? What Causes This

Ambient temperature is below 0°C, or sensor fault indicating unusually low operating temperature.

How to Fix It

  1. Ensure the operating environment temperature is maintained above 0°C (32°F).
  2. Move the unit to a warmer location if necessary.
  3. Check for proper ventilation to allow heat dissipation.
  4. If temperature is confirmed above 0°C but alarm persists, the temperature sensor may be faulty and require service.

Source: page 45 of the official manual

From the manual

Manual page 45 — Upgraded error CPF09

This error code appears in:

Upgraded 30A Solar Charge Controller