SCHURTER White Paper: Protection Class II0 pages

Protection Class II

White Paper

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Safe Power For Medical Devices
Used At Home
Multi-functional Connectors According to IEC 60601-1-11 with
Protection Class II
An aging population and the rising cost of healthcare around the world are a matter of concern
to the general public these days. This is especially true in the USA, where keeping costs under
control becomes more and more challenging. In order to reduce the cost of overhead, while offering increased levels of care by way of technology, we are seeing a trend towards medical care at
home. Along with this trend is increasing demand for smaller, more portable and efficient medical
equipment. While the shorter stay in overcrowded hospitals is saving costs in the health industry,
manufacturers of medical devices are being presented with new challenges to minimize the safety
risks associated with the use of medical devices. Medical devices used at home are being operated by laypersons with no medical training, instead of trained personnel in a controlled hospital
environment. Regulatory requirements have been established to provide safety measures specifically for these users.
As an important addition to the basic standard
IEC 60601-1 for medical devices, IEC 60601-111 describes requirements about medical
equipment used in the home. The developers
of such devices or components have to
observe additional requirements as it relates to
safety in addition to specifications about
marking (simple operation) and documentation
(for example, understandable operating
instructions). The utmost care has to be
exercised when it comes to powering the
device. The safety requirements according to
IEC 60601-1-11 can be summarized as follows:
- t Altered ambient conditions (domestic tt
tenvironment)
- t Protection Class II
- t Minimum IP 21 degree of water and dust
tprotection
- t Stricter shock and vibration tests
A key criteria is most certainly the responsibility
to provide Protection Class II safety, as well as
equipment immunity to electromagnetic
interference.

Safe power supply for medical equipment used at home
Domestic power supply systems, unlike
installations in hospitals, are not always reliable
or may be insufficiently grounded. A medical
device used at home has to compensate for
this potential. It is therefore imperative that it be
designed with Protection Class II safety.
Protection Class is defined in safety standards
that offer protection against dangerous contact
voltages. Devices in Protection Class II have

double insulation between the mains circuit and
the output voltage or metal enclosure. Even if
they do have electrically conductive surfaces,
they are protected against any contact with
other live parts through the double insulation.

5008: C8 appliance inlet with filter
Icon for Protection Class II
The icon for Protection Class II symbolizes two
insulation layers and is affixed to all Protection
Class II devices.
The protective insulation has to be reinforced
according to the general standard IEC 61140 for
protection against electric shocks or be double
that of Protection Class I. A second insulation
for the power feed is a common solution.
Doubling the clearance and creepage
distances for all live contacts also has the same
effect as a double insulation. This ensures that
the two conductors, consisting of the phase
and neutral conductor, are sufficiently insulated
against all other surfaces that can be touched. If
the surfaces that can be touched are
electrically conductive, the gaps and
insulations also have to be doubled. The
clearance and creepage gaps for Protection
Class I are 4 mm between live conductors and
metal enclosures or ground conductors. This
value is doubled in Protection Class II,
corresponding to a gap of 8 mm between live
conductors and a metal enclosure.

EMC-Products

A C8 style IEC connector with a maximum rated
current of 2.5 A is suitable for all devices with
outputs up to approx 500 W. Matching
connecting cables are available with 2-pin Euro
and
National
Electrical
Manufacturing
Association (NEMA) plugs.

C8

C18

The C18 connector, with a rated current up to
10 A VDE and 15 A UL is available for medical
devices with higher outputs.

C18 PEM connector 5707 with V-Lock
locking system and IP 65 protection

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