常遇到的问题：
　　　　“如果为了清理污水坑，我不得不使泵运行在低水位，这时会出现什么情况？”
　　答：
　　　　如果是为了清理、检查或维护，那么泵运行水位完全低于湿井的规定水位是可接受的。这在使用中常见，不应该会导致任何设备的破坏。但是，长时间在超低水位下运行泵设备，应该避免或预防由于“涡流”现象可能导致的泵密封装置老化现象。
　　A common question:
　　"What if I operate my pump at a very low level for sump cleanout purposes?
　　Answer:
　　It is normally acceptable to pump the wet-well completely down for purposes of cleaning, inspection or maintenance. This is a common practice and should not result in any damage to the unit. Sustained operation at extremely low levels should be avoided to prevent premature pump seal damage from "vortexing".

　　结论
　　Conclusions

　　无论选择哪家泵制造商，在设计泵系统和配置无堵塞潜水泵时，泵设计师和最终用户都应该考虑电机过热和“涡流”预防两个问题。正确考虑这两个问题将有助于用户确定适当的污水坑直径和水位控制高度。
　　Pump system designers and end-users should consider both motor overheating and prevention of "vortexing" (inadequate suction conditions) when designing systems and specifying non-clog submersible pumps, regardless of the preferred pump manufacturer(s). Proper consideration of both items will help the customer determine suitable sump pit dimensions and level control elevations.

　　对于湿井设备安装，建议所确定的低水位高度应该达到或超过预防涡流的最小潜水深度。多数情况下，人们会发现所建议的预防涡流的最小潜水深度会等于或大于预防电机过热的最小潜水深度。这在实践中是正确的，但是前提是潜水电机性能完全符合由美国潜水污水泵协会（SWPA）所推荐的美国电气制造商协会标准的设计指标。因此，一旦配置了适当的防涡流潜水深度，通常就不需要担忧电机过热。
　　For wet-pit installations, it is recommended that the low water level elevation be specified to meet or exceed the minimum submergence to prevent vortexing. In many cases it will be found that the minimum recommended submergence to prevent vortexing will be equal to, or greater than, the minimum submergence required to prevent overheating. This is particularly true if it has been confirmed that the submersible motor has been rated in strict conformance with NEMA standards as is recommended by the Submersible Wastewater Pump Association (SWPA). Thus, once proper anti-vortexing submergence is established, the concern about motor overheating will frequently be eliminated.

　　对于需要在非潜水状态下进行连续运转的应用领域，例如干井潜水泵设备，建议设计工程师所配置的电机必须要最适合这类应用场合。对于污水或类似的包含固体颗粒、油脂或脂肪的水混合物，闭合回路冷却电机设计结构是最好的选择，只要所需的功率大小超过常规潜水电机降级的使用限制指标。
　　For applications that require continuous non-submerged operation, such as dry-pit submersible installations, it is recommended that the design engineer specify the motor type best suited for the intended service. For sewage or similar water-based mixtures containing solids, grease or fat, the closedloop-cooled motor design is the preferred choice whenever the horsepower size required exceeds the practical limit for de-rating of conventional submersible motors.

　　因为所有应用都有特殊的要求，泵制造商应该向用户咨询，根据实际应用情况对自己的泵设备作出适当的修改，以便所推荐的设备能够符合用户的实际要求。
　　Since all applications have specific requirements, the pump manufacturer should be consulted for verification of the proper application of their products and for recommendations of specific equipment for the intended service.