Here are some possible explanations:
Orientation Sensors:
The Dolphin S200 likely has orientation sensors to determine its position. These sensors help the cleaner navigate the pool and ensure it's operating correctly. When you flip the unit upside down, these sensors might not be able to function properly, leading to the unit behaving as if it were in the pool.
Self-Diagnostic System:
During its self-diagnostic routine, the unit checks various components such as motors, impellers, and sensors. If the unit is upside down, the diagnostics might behave differently because the sensors are receiving unexpected data, causing the unit to continue running as a safety precaution or due to a misinterpretation of the orientation.
Cooling System:
Robotic pool cleaners are designed to be cooled by the water in the pool. Running the unit outside of the water, especially upside down, might cause it to keep running to prevent overheating. This continuous running could be an attempt to keep the internal components cool by maintaining air circulation.
Common Issues and Solutions
Impeller Motor and Brushes:
Since you've identified that the brushes on the impeller motor are worn and have ordered a rebuild kit, this could indeed be part of the issue. Worn brushes can cause intermittent operation or reduced performance, leading to the cleaner stopping after moving a short distance in the pool.
Sensor Calibration:
Ensure that all sensors are clean and free from debris. Sometimes, dirt or buildup can cause the sensors to give incorrect readings.
Software or Firmware Issues:
Check if there's a firmware update available for your Dolphin S200. Manufacturers occasionally release updates to improve performance and fix bugs.
