– be so designed that they cannot be replaced in an incorrect position, and that, if they are
omitted, the tool is rendered inoperable or manifestly incomplete.
Compliance is checked by inspection and by manual test.
Servicing includes replacement of components such as supply cords and switches.
This requirement is met if the barrier is so fixed that it can only be removed by breaking or cutting.
Fixing by means of rivets is allowed, provided that these rivets need not be removed when replacing the
brushes, capacitors, switches, non-detachable flexible cables and cords and the like.
Fixing by means of an adhesive is only allowed if the mechanical strength of the joint is equal to that of
the barrier.
An adequate internal lining of insulation material, or an adequate internal insulating coating on metal
enclosures, is considered to be an insulating barrier provided that the coating cannot easily be removed
by scraping.
For class II tools, a sleeve on an insulated internal conductor, other than the core of an external flexible
cable or cord, is considered to be an adequate insulating barrier, if it can only be removed by breaking or
cutting, or if it is clamped at both ends.
Ordinary lacquering on the inside of metal enclosures, varnished cambric, flexible resin-bonded paper, or
the like are not considered to be insulating barriers.
21.10 Inside the tool, the sheath (jacket) of a flexible cable or cord shall only be used as supplementary
insulation where it is not subject to undue mechanical or thermal stresses.
Compliance is checked by inspection.
21.11 Any assembly gap with a width greater than 0,3 mm in supplementary insulation shall not be
coincidental with any such gap in basic insulation, neither shall any such gap in reinforced insulation give
direct access to live parts.
Compliance is checked by inspection and measurement.
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