Medical electrical equipment must not endanger patients or staff. Schurter guides buyers through some of the safety considerations.

Medical devices connected to a detachable power cord must meet the requirements of IEC60320. It is also recommended to avoid unintentional unplugging. For example, with Schurter’s V-Lock cable retention solution, the power outlet has a slot that locks with the cable connector lock and prevents accidental removal.

Permanently installed medical electrical equipment is available with its own fuses. It is recommended that all such equipment be equipped with a bipolar fuse holder and that only authorized personnel be able to remove or replace the fuses. The basic standard for medical electrical equipment, IEC / UL 60601-1, defines fuse holders that can only be reached with a tool. That’s why Schurter offers Extra-Safe safety drawers.

The power line switch ensures that the equipment is completely disconnected from the power supply after being turned off. If only one pole in an unpolarized distribution network is broken, the equipment may still be live. It is preferable to use a switch that turns off the power to two poles.

The power line filter protects the equipment from external high frequency interference and reduces high frequency interference emitted by the equipment. They are often needed to meet EMC standards for the CE declaration of conformity.

Filter capacitors cause leakage currents, which in medical electrical equipment cannot exceed 100 µA under normal conditions (10 µA for direct contact with the patient). Thus, power line filters for medical equipment do not have Y capacitors or are very small, resulting in a maximum leakage current of 5µA or 80µA.
The capacitors used are connected directly between the supplied wires (X capacitors) or between the supplied wires and ground (Y capacitors).

If the power cord is unplugged, the voltage stored by capacitors X is still present on the power pins and may cause electric shock if touched. A discharge resistor is placed between the phase and neutral conductors to discharge the capacitor.

Medical safety starts with power input

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