Control cabinet

Monitoring shows how warm and humid it actually is inside the control cabinet and thus provides the basis for optimising thermal management and the energy consumption of cooling. In ifm’s solution, one LDH292 IO-Link multisensor each measures temperature and relative humidity inside and outside the cabinet, so the influence of ambient temperature is also taken into account. Limit values are based on the data sheets of the installed devices.

Residual current monitoring shows early on when faults or damage are developing in an electrical installation, for example due to wear or faulty connections. Doepke’s e.Guard captures residual currents in short cycles, so that load peaks and brief voltage dips during start-up are also detected. A gateway based on the Revolution Pi visualises and documents the curves. This allows users to dispense with the recurring insulation test under DIN VDE 0105-100/A1.

Sensors in the control cabinet are connected to an IO-Link master, which passes their values to the software via an IoT port. In ifm’s solution, multisensors for temperature and humidity, a temperature sensor on the transformer with an evaluation unit and electronic circuit breakers are connected to masters such as the AL1350. The values reach moneo every second. If a circuit breaker trips, the device status reports it and moneo notifies the people responsible by email.

IEC 62443 requires suppliers and integrators to assess the risks of an automation system jointly and derive protective measures from them. SCHOTTEL and WAGO followed IEC 62443-3-2: risk analysis, asset management from the control stand on the bridge to the local control stand at the control cabinet, division into zones, threat analysis and countermeasures. Finally, they defined test procedures to verify that these measures are effective.