US 6,715,996 B2 · Method for the operation of a centrifugal pump

Abstract

A method for the operation of a centrifugal pump (2) driven by an electric motor (5) with variable frequency, wherein too small a flow through the pump (2) is ascertained by monitoring electrical quantities, and a pump arrangement (1) having a centrifugal pump (2), an electric motor (5) which drives the centrifugal pump (2), a controlled frequency converter (6) which feeds the electric motor (5), a sensor device (12, 13) and an evaluating device (15-19) are described. It is desired to detect, by simple means, when no through-flow is present. For that purpose, the electrical power is ascertained and compared to a control quantity formed as a function of the frequency of the motor (5). The sensor device ascertains values for determination of the electrical power, and the evaluating device has a dynamic limit value former (18), which forms a control quantity as a function of the frequency of the motor (5).

Claims12

Dependent claims

An electric motor for driving a pump, comprising:

control electronics for determining the frequency of rotational speed of the pump motor,
a frequency sensor for detecting the frequency of the pump motor,
a power sensor for detecting electrical power consumed by the pump motor,
a computational device for calculating a threshold reference power level which would be present at a predetermined condition that would lead to a malfunction of the motor, for at least one frequency of the pump motor,
a comparator that compares the electrical power actually consumed by the pump motor to the threshold reference power level, and
a switch for disabling the pump motor when the comparator senses that the electrical power consumed by the pump motor is less than the threshold reference power level.

3 more elements

Dependencies are inferred from the claim text.

Method for the operation of a centrifugal pump

Life of this patent

Method for the operation of a centrifugal pump

Life of this patent

Abstract

Claims12