Submersible Sump Pump

Submersible Sump Pumps - for when basement flooding would suck

This type of pump can be industrial or residential in use, and can be electrically or air driven with float-type actuators that start the pump when the water level reaches a predetermined level. These pumps are frequently used in situations where they are necessary to prevent serious flooding, and where, if they fail, the consequences can be potentially disastrous. In such situations, battery back-up pumps are normally provided that are actuated both on the failure of the main power system, and at a secondary float level.

This setup provides protection against both power outage and power reduction resulting in a low pump rate. Routine maintenance includes inspection of the basement or pit to ensure the absence of solid matter which could block the pump intake - and sand or grit can cause undue wear. There are two main types of sump pumps - the pedestal and submersible.

In practice, the submersible pump sits in a small pit set into, for example, the basement. As water accumulates it starts to fill the pit, and raises a float until it reaches a level where it completes the electrical circuit and starts the pump. Because it is submerged, it's not often easy to maintain and repair - its construction is such that submersible pumps are frequently not possible to repair should anything go wrong.

In contrast, a pedestal pump is a system powered by a motor elevated higher than the activation float level. It is generally mounted above the sump pit, and is consequently easier to maintain. The pedestal type of pump is less expensive than the submersible type, but is noisier due to the differences in construction, and the lack of sound insulation provided by the water.

Submersible pumps are manufactured in a way to insulate the electrical parts from water. The casing containing the electrical parts is then potted with a liquid resin forming a solid mass impervious to water - sealed so that no water can reach the electrical parts and cause a short circuit.

All the moving parts are held in a separate casing away from the main electrics allowing for safe submersion in water. Although more expensive than pedestal pumps they are quieter in operation. They also last longer because the moving parts are sealed and oil cooled. If a back-up battery pump is used, there is a second float that is set to actuate at a higher level.

Submersible sump pumps are normally made from cast iron, stainless steel or plastic, though the plastic type is used more in a domestic situation than industrial. Sump pumps should be properly maintained, since their failure could be costly. This should consist of at least an annual full inspection for wear and to ensure that the seals are not damaged in any way. The moving parts should also be checked to ensure that they are moving freely. The more frequently the pump is operating, the more frequently it should be inspected.

Submersible sump pumps are normally made from cast iron, stainless steel or plastic, though the plastic type is used more in a domestic situation than industrial. Sump pumps should be properly maintained, since their failure could be costly. This should consist of at least an annual full inspection for wear and to ensure that the seals are not damaged in any way. The moving parts should also be checked to ensure that they are moving freely. The more frequently the pump is operating, the more frequently it should be inspected.