Personal and plant protection in the operation of the Wald-Klinikum Gera

In the course of the general renovation of the Wald-Klinikum Gera, the complete electrical systems and operating equipment were brought up to the latest state of the art with the highest level. Due to the high quality requirements on it, the responsible persons decided for modular devices of the series GREEN ELECTRIC of Kopp. A total of more than 2,800 miniature circuit breakers and 1,300 residual current circuit breakers ensure reliable protection of all electrical circuits, thus ensuring the safety of hospital staff and patients.

Electrical systems in hospitals

A large number of mains-operated electrical devices and machines are used in everyday hospital life. A sudden failure of the power supply would have fatal consequences, which is why the requirements for personal safety and failure safety of electrical systems and equipment are particularly high. In addition to the required electrical power, laws and standards must be observed. The basis for system dimensioning is VDE 0100 “Erection of low-voltage systems”. Part 710 of the standard defines the requirements for electrical safety in areas used for medical purposes.

Normative requirements for medical devices

These areas are divided into groups 0, 1 or 2. 0 classifies medical areas in which an interruption of the power supply is harmless for the safety of patients. In class 2 areas, however, power failures are life-threatening. In case of malfunctions, further operation must be guaranteed within a few seconds.

Avoid unwanted interruptions of operation

To protect against body currents and electromagnetic interference (external voltages), Class 2 areas have two independent power supply systems. In addition to the TN network, the IT system with insulation monitoring ensures the supply of life-sustaining ME devices and ME systems. The unearthed IT systems also offer an inherent protection against dangerous body voltages. However, IT systems are becoming increasingly complex and have a high grid leakage capacity.

 

RCDs increase operational safety and system availability

Class 0 and 1 medical areas are supplied from the main distribution board via a TN-S network. The insulation resistance is determined indirectly via the level of the residual current. A residual current device (RCD) is used for this purpose, which switches off the system or the consumer when a defined residual current is exceeded. In Class 1 areas, it must be ensured that no undesired switch-off occurs when several electrical consumers are connected to a circuit at the same time. In this case, tripping causes all circuits – even fault-free ones – to be switched voltage-free. For this reason, DIN VDE 0100-410 recommends distributing the circuits of a system to several residual current protection devices. This means that essential parts of the plant can continue to operate when a single fault occurs.

Green Electric for highest quality requirements

For the use of ME equipment and ME systems, RCDs must be used which prevent undesired switching off of the equipment due to mains spikes. This demand can be converted in accordance with the DIN VDE 0100-710 optimally with the distribution installation devices GREEN ELECTRIC of Kopp. The RCD detects alternating as well as pulsating direct currents and switches off within 0. 2 seconds.