More than just pump protection: condition monitoring

2024-04-03 Products, Water and wastewater industry

A new, innovative solution from Kriwan Industrie-Elektronik bridges the gap between pumps, protective functions, and the digital world. The integrated Modbus interface ensures easy networking. The highlight: power measurement of the electric motor, which also functions at the inverter.

The requirements of water management systems regarding protection, digitization, and energy efficiency are growing. For instance, pump manufacturers have had to improve their systems in recent years to detect increased solids loading in wastewater due to blockages and simultaneously offer protective or remedial measures. Another example is the increasing threat of cyberattacks, while all components of a system are expected to interconnect and exchange data. It's a difficult yet necessary balance to operate pump systems securely and leverage the opportunities of digitization.

Kriwan Industrie-Elektronik now makes it even easier to network pumps. The new pump protection INT69 PYF Diagnosis provides the captured measurement values and operating data of the pump via the integrated Modbus interface. Thus, the operator can receive early information and warnings and take timely countermeasures before failures occur. A second complex measuring system directly at the pump is rendered unnecessary.

To safeguard the local protection concept against misoperation and potential cyberattacks, the pump protection via Modbus interface has no rights for parameterization. These are performed directly on the protection device for security reasons or via a separate Modbus gateway.


Measuring power even during inverter operation

The power consumption of an electric motor is one of the most important parameters. It provides significant information about the operating point and condition of the application. The same applies to pumps; information about power is often crucial. In addition to the integrated Modbus RTU interface, the major innovation of the INT69 PYF Diagnosis is the measurement of active, reactive, and apparent power, as well as the power factor cos ϕ. Additionally, counters for consumed active and reactive energy are included in the integrated memory of the pump protection device. This allows transparent presentation of energy consumption. A significant unique feature of the pump protection is its ability to measure the power of electric motors even when using frequency converters. For this purpose, a new current transformer has been developed, which provides the highest possible measurement accuracy of amplitude and phase over a wide frequency range. The phase error is in the range of 20…100 Hz at < 1°, which particularly positively impacts the accuracy of active power.

Depending on the decrease or increase in power, the device can detect dry running, closed valves, or rotor blocking in the motor due to a blockage. The combination of additional sensor data such as motor, bearing temperature, and vibration provides more detailed information about faults and anomalies, offering additional protection.

Thanks to the App, Everything is Under Control

The user can access the pump protection device on-site with the help of the Kriwan Intspector App. In the diagnosis section, there are helpful functions such as operating data, event lists with timestamps, error counters, operating times, switching cycles, current measurements, and much more for a more precise analysis of the pump. With the help of live diagnosis, all measured values can be recorded over a longer period and saved on an end device (smartphone, tablet, or laptop) as a CSV file. In this way, the user saves on expensive measuring equipment and uses the end device as a data logger. In the parameterization, each input in the protection device can be individually adjusted, for example, the temperature inputs (PTC, Pt100, Pt1000, and bimetallic). If an input is not used, it is set to disabled. Similarly, the parameterization of warning, set, and trip values, trip and reconnection delays, or a locked shutdown without automatic reconnection per input is possible.


A unique selling proposition (USP) of the pump protection: power measurement of the motor at the inverter.

This allows every value to be individually parameterized for each application. Operators can also create, save, and reload entire parameter datasets via the app. This saves time in recurring applications. In addition to the voltage and current inputs, the multi-protection device also has inputs for temperature (3x), leakage (1x), float switch as a switching contact (1x), and analog input 0/4-20mA (1x), for example, for vibration sensors. The phase monitoring includes phase sequence, failure, and asymmetry as well as over and under-voltage. The use in single-phase networks is also possible. One relay each for alarm and warning ensure the necessary operational safety. In addition, monitoring of power factor cos ϕ, operating hours, switching frequency, short circuit, and interruption of the sensors is possible. The device calculates and displays the recorded apparent, active, and reactive power and counts active and reactive energy. With the multitude of inputs and functions, the INT69 PYF Diagnosis from Kriwan Industrie-Elektronik fits perfectly into the pump protection concept. It helps operators meet the increasing requirements, not only in water management. Last but not least, compared to conventional protection concepts with only 45 mm housing width, it also saves space in the control cabinet.

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