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Protective device for a controlling system of a sewage pump

Protective device for a controlling system of a sewage pump description/claims

1. Field of the Invention

The present invention relates to a protective device for a controlling system of a sewage pump, and more particularly to an electronic-type protective device that controls pump operation and has a protective unit protecting a start capacitor in the controlling system to avoid the start capacitor from burnout.

2. Description of Related Art

As shown in FIGS. 3 and 4, a conventional sewage pump system in accordance with the prior art has an operational controlling circuit system 2 for controlling the operation of a sewage pump 1. The operational controlling circuit system 2 has a start capacitor 21 connected with a run capacitor 22 in parallel connection and with a switch 3 in series connection and further connected with an actuating coil and an operating coil on the sewage pump 1 to perform a combined circuit. In the operational controlling circuit system 2, the actuating coil 11 and the operating coil 12 drive the sewage pump 1 to function when the electrical power is supplied. Meanwhile, the switch 3 mounted on a shaft 4 of the sewage pump 1 has its contact changed from a normal closed (N.C.) status to a normal open (N.O.) status by a centrifugal force of the rotation of the shaft 4. Thereby, the start capacitor 21 is disconnected with the power supply to stop discharging so that the start capacitor 21 is protected from burnout and breakdown caused by the discharging or charging operation for a long period. However, the switch 3 is always kept being switched between the NO and NC status and its contact has carbon-deposition or oxidation incurred by electric sparkles of large current. Thus, the contact can not successfully disengage and is kept at the normal closed (N.C.) status that makes the start capacitor 21 to electrically connect the power source. When the start capacitor 21 is kept in discharging status, it will burnout sooner or later and then actuating coil 11 and the operating coil 12 will burnout as well.

According to above description, the conventional sewage pump system still has some drawbacks in use.

A main objective of the present invention is to provide a protective device for a controlling system of a sewage pump, wherein the protective device protects a start capacitor from keeping discharge and burnout when a switch is abnormally suspended.

To achieve the foregoing objective, the protective device for a controlling system of a sewage pump with a start capacitor and a run capacitor, the protective device comprising a protective unit having an analogic or digital electronic circuit with a cutter function to provide a protective efficiency to avoid the start capacitor in the sewage pump from burnout.

By having the protective unit, the start capacitor is protected from burnout and thus has an extended lifespan.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

FIG. 1 is a cross-sectional view of a sewage pump system with a protective device in accordance with the present invention;

FIG. 2 is a schematic circuit diagram for the sewage pump system with the protective device in the present invention;

FIG. 3 is a cross-sectional view of a conventional sewage pump system in accordance with the prior art; and

FIG. 4 is a schematic circuit diagram for the sewage pump system in accordance with the prior art.

• Provisional Patent
• Utility Patent

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