Description of application and basic function

The standards demanded of molded case circuit breakers in terms of their electrical and mechanical properties, cost-effectiveness and adaptability are increasing as a result of ongoing rationalization and automation. The merging of power distribution engineering and information technology has opened up a diverse range of new applications for molded case circuit breakers.

Potential applications

The power distribution system can be integrated into the information system of the relevant application, but it can also have its own independent information system.

Siemens considers the following three scenarios as potential applications:

The TIP application scenario offers coordinated power distribution in all phases and on all levels as well as the benefit of an integrated information and communication structure.

Totally Integrated Automation (TIA) and Totally Integrated Power (TIP)

Total Building Solution (TBS) and Totally Integrated Power (TIP)

Communication during all life phases of a power distribution system

Communication provides useful support during all life phases of a power distribution system, i.e. during

  • engineering and installation,

  • operation, and

  • maintenance and expansion.

The communication functionality of 3VA2 molded case circuit breakers can be used in different ways to perform various tasks such as

  • commissioning by installation personnel,

  • operations management by the maintenance department,

  • power management by accounting managers, and

  • process control by production managers.

3VA2 molded case circuit breakers can adapt to operate with the communication systems implemented for individual fields of activity.

The communication capability of the 3VA2 is supported by the electronic components of the molded case circuit breaker such as the ETU electronic trip unit and the RCD residual current device. Information is made available for individual tasks via a range of different communication interfaces and protocols, such as


  • Modbus RTU

  • Ethernet (Modbus TCP) and

  • TD500 test device.

Maintenance management example

Information for preventive maintenance, e.g. number of switching cycles or operating hours, enables timely planning of personnel and material. Plant availability increases as a result and irreparable damage to sensitive plant components caused by failures can be avoided. Communication provides fast access to specific information about the location and cause of power failures.

One example of tripping information:

Trip caused by 2317 A short circuit in phase L2 on August 27, 2013 at 14:27 p.m.

The specific details contained in this message are the basis for fast correction of the fault and create a significant potential for cost savings.

Statistics and cost-effectiveness

Recording of electrical power, energy and the power factor opens up further possibilities. Energy profiles for power distribution structures can be created and the costs can be clearly allocated thanks to the transparent representation of energy consumption for business administration analysis. Energy costs can later be optimized by compensating for load peaks and troughs.

Automation technology

SIMATIC-based solutions for the process and manufacturing industry

A key feature of the process and manufacturing industry is its very high power consumption. It therefore makes sense to integrate a power data management system into existing systems.

Communication via PROFIBUS DP

PROFIBUS DP enables integration of a wide range of devices:

  • Devices for the protection of distribution boards and loads: Protective devices, such as circuit breakers

  • Open-loop and closed-loop control devices: Frequency converters, motor management systems and soft starters

  • Equipment for acquisition of the following information:

    • Electrical measured variables: via 7KM PAC3200/4200 measuring devices

    • Non-electrical measured variables: via analog/digital converters


An increasing number of devices in automation technology offer PROFINET. A 7KM PAC Switched Ethernet PROFINET expansion module is also available for the 3VA molded case circuit breakers and the 7KM PAC3200 and 7KM PAC4200 measuring devices.

PROFIenergy is a "Common Application Profile" from Profibus International. Thanks to PROFIenergy it is possible to create a power data management system with standardized device interfaces.

Building automation

Intelligent buildings with Total Building Solutions

Unlike structures of the past, modern buildings need to meet many different criteria. Building services with integrated disciplines such as building automation, fire safety, security, lighting, and low-voltage power distribution are often indispensable and form the core of a total building solution. The objective of a total building solution is to achieve optimum integration of these disciplines in order to make buildings safer, more comfortable, more economical, and more efficient.

3VA molded case circuit breakers are particularly helpful in meeting power consumption and comfort targets and should be incorporated via a communication interface into the building automation system of the Desigo total building solution.

Power management with powermanager

Siemens offers the powermanager software application, which is designed for power and plant monitoring applications. When used in conjunction with SENTRON measuring devices such as 3VA, 3WL, 3VL and PAC as well as equipment supplied by third parties, powermanager is a power monitoring system that reduces energy costs and increases the availability of electrical supply and distribution systems.

powermanager acquires the measured variables that are needed to optimize power consumption and so reduce costs. These variables not only include energy and power values, but also electrical parameters such as current, voltage, or power factor. Not only is this system able to display values, but also to monitor and archive them for later analysis. In addition, the load monitoring function is capable of monitoring a specified setpoint and making recommendations as to which loads should be connected and disconnected.

Identifying savings potential

The power monitoring software has been tested by the TÜV Rheinland for its suitability to support a power management system in accordance with ISO 50001.

Functionality and user-friendliness

The salient features and functions of the power monitoring software are as follows:

  • Good scalability

  • Enhanced report templates

  • Response plans

  • Mass parameterization

  • Virtual measuring points for computing customer-specific parameters

  • Load monitoring function for monitoring specified power limits for freely definable time periods

  • Switching recommendations in the event of limit violations

  • Remote control of circuit breakers