When mounting a thermostatic expansion valve sensor bulb, which of the following is NOT a requirement?

The mounting of a thermostatic expansion valve (TXV) sensor bulb involves specific requirements to ensure accurate temperature readings and optimal system performance. The correct answer indicates that the position of the sensor bulb does not need to be above the compressor.

In reality, the primary factors for the sensor bulb's placement relate to its ability to sense the temperature of the refrigerant accurately. Insulating it from ambient temperature ensures that it only responds to the temperature of the suction line and not to fluctuations in the surrounding environment. The requirement for the sensor bulb to be slightly clamped to the suction line helps maintain intimate contact, allowing for accurate sensing of the refrigerant temperature. Clean contact surfaces are critical as any contamination could impair the thermal conductivity and lead to inaccurate readings.

Therefore, the positioning of the sensor bulb above the compressor is not a mandatory requirement. It can be placed at various locations along the suction line as long as it meets the other conditions for effective operation. This allows for flexibility in installation while ensuring that the essential functional criteria are maintained.