Medical Power Entry Modules with Filter by Schurter

IEC/UL 60601-1 requirements and PEM solutions with filter by Schurter

Miroslav Piskor, a Product Specialist at SOS electronic, has prepared a summary of the basic requirements of the IEC/UL 60601-1 standard and solutions from Schurter. Thanks to these solutions, electrical devices containing their PEM with a filter meet the demanding requirements in healthcare and home care. 

Power cable

Requirement

Protection of any power connection against unintentional removal of the plug from the equipment’s power socket.

Schurter Solution

• Cord retaining kits 4700.00XX
• Screw brackets for universal use 0888.00XX
• Power cord and PEM with V-Lock. Power socket is equipped with a notch that interlocks with a special latch on the connector on the power cord.

Water Protection

Requirement

IP21 is required for all medical home care equipment (IEC 60601-1-11). Other medical applications may require even higher protection.

Schurter solution

Power entry modules with protection against ingress of water:

• 5707: IP65 between PEM and device box and IP54 for connected power cord with V-Lock
• DG11, DG12: IP65 between PEM and device box and IP54 for connected power cord with V-Lock

Fuse Holders

Requirement

Energized supply leads (L) have to be protected by a fuse to minimize the risk that if a failure occurs, the mains circuit breaker might be tripped and disconnecting other, maybe life-critical devices. In some countries the mains plug is not polarized => the power conductor could be on a neutral line! (e.g. CEE plugs in Europe)

Schurter Solution

PEM with a two-pole fuse holder is recommended for all medical electrical equipment.

Requirement

Fuse holders can only be opened with the help of a tool (IEC 60601-1: 5.9.2.1, 8.11.5.).

Schurter Solution

PEM with the “Extra-Safe” fuse drawers and PEM with screw-in fuse drawers (5707 series).

Mains Switches

Requirement

Equipment should be completely disconnected from the power network after being turned off (IEC 60601-1: 8.11.1.).

Schurter Solution

PEM with a two-pole switch that disconnects the power feed on two poles.

Filter – Leakage Currents through PE (filter chassis)

Capacitors wired between the L, N, and PE are Y-capacitors. They produce a leakage current to PE. (current value depends on capacitance, the power-line voltage and frequency).

Requirement

Leakage current for medical electrical equipment must not exceed:

• 100 µA for devices without direct operator contact, Means Of Operator Protection (MOOP)
• 10 µA for devices with direct patient contact, Means Of Patient Protection (MOPP)

(IEC 60601-1: 8.7.3.)

Schurter Solution

Power-line filters for medical electric equipment either have no (MOPP -> Schurter M5) or very small (MOOP -> Schurter M80) Y capacitors.

Filter – Safety Capacitors

Capacitors in power-line filters that are wired directly between the L and N conductors are X-class capacitors. Capacitors between L, N, and PE are Y-class capacitors.

Requirement

Y capacitors in medical equipment:

• Class Y2 for equipment without direct patient contact (MOOP)
• Class Y1 for equipment with direct patient contact (MOPP)

(IEC 60601-1: 8.5.1.)

Schurter Solution

Schurter M5 PEMs with filter do not contain class Y capacitors. M80 PEMs with filter meet the requirements of IEC 60601-1: 8.5.1.

Filter – Energy Stored in Capacitors

If you unplug the power cord from the outlet, the voltage from the capacitors is present on the power pins until the capacitors are discharged.

Requirement

1 second after unplugging the power cord, the voltage on the pins that can be touched by the operator must be a maximum of 60V (IEC 60601-1: 8.4.3.).

Schurter Solution

PEM with bleeder resistor between the phase and neutral conductors.

Filters – Attenuation

Filters with small Y capacitors (MOOP) or without Y capacitors (MOPP) have low high-frequency attenuation for asymmetric mode (L, N - PE). The situation can be improved a little bit by a filter with ground choke.

Attenuation of standard (1), M80 (2) and M5 (3) 1A filters and 1A M5 filter with ground choke (4).

Home Care Medical Equipment

Requirement

IEC 60601-1-11 requires:

• Protection Class II (Double Insulation)
• Test voltage 4 000 V between L/N and the filter case
• Minimum protection against water IP21

Schurter Solution

PEM with:

• C8 or C18 inlet connectors (without PE)
• Reinforced insulation inside of the filter
• 8 mm surface and air distances between live parts and the filter housing
• PEM will withstand a test voltage greater than 4000 VDC between L/N and the filter housing
• Topology without Y capacitors

Discover more interesting solutions for electrical devices intended for healthcare and home care in our product range in the special 'medical' product category and in our articles.