What operational feature differentiates a semi hermetic pump from other types?

The distinguishing operational feature of a semi-hermetic pump is its external motor connection. In semi-hermetic designs, the motor is physically separated from the refrigerant flow yet still housed within the same shell or casing as the pump, which provides ease of maintenance and access to the motor without needing to open the refrigeration system entirely. This setup allows for efficient thermal management and minimizes leakage risks, as the motor components are isolated from the refrigerant, ensuring a safer and more efficient operation.

In contrast, open motor designs typically expose the motor directly to the environment, which is not the case with semi-hermetic pumps. Submerged operation refers to the complete immersion of the pump in the fluid being pumped, which is also different from the semi-hermetic design. Finally, while compact size can be a feature of many types of pumps, it is not specific to semi-hermetic pumps and does not provide the defining operational characteristic that sets them apart.