Medical equipment

Transformer systems are now widely used in medical fields such as operating rooms, intensive-care unit rooms and cardiac monitoring rooms. On the one hand, the protection provides a safe and reliable power supply for the medical appliances in the place, on the other hand, it can also ensure the safety of patients. In the Medical International Electrotechnical Commission, the IEC 60364 provides that in the medical field, electrical medical equipment for life-sustaining or surgical purposes, and lighting and similar lighting for operating rooms, is powered by a power grid, equipment rated above AC25V or DC60V must use an IT system with an insulated resistance monitor.

In order to ensure the continuity of power supply to the system, state 《 electrical installations in buildings part 7-710: requirements for special installations or places-medical places 》 GB16895.24-2005/IEC60364-7-710:2002710.53.1 stipulates: “Overload protection is not allowed in the transformer inlet and outlet circuits of medical IT systems”, to prevent system overload protection switch off power supply.

This requires the insulation monitor in the system must also have load detection and overload alarm function. In some important places, due to the continuous operation of the isolation transformer, the temperature may be too high and lead to abnormal operation of the isolation transformer. Therefore, the insulation monitor also needs to detect the transformer's temperature in real time. When the temperature is too high, there should be corresponding over-temperature alarm signal to remind the relevant personnel to deal with it in time. From the above analysis, a typical single-phase IT system, its components include: Isolation Transformer, insulation monitor, current transformer, and external alarm and display.