Flygt 11507 Flight CAS Unit is an industrial controller used for monitoring and protecting submersible pumps, integrating temperature, pressure, and leakage sensors into a relay‑based protection scheme. Common failure modes include power supply dropout or voltage spikes damaging the onboard regulator, corrosion or shorting of sensor input terminals, and degradation of the internal MOSFETs that drive the pump shut‑off contactor. First‑check diagnostics: verify 24 VDC/48 VDC supply continuity and correct polarity; inspect all sensor leads for physical damage or loose connections; review any fault codes displayed on the unit’s status LEDs or through its serial interface.[oss-gpt-20b]