Brochure

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Miniature snap switches
OsiSense XC
Miniature design
General
Presentation
Electromechanical detection
b OsiSense XC miniature snap switches, featuring electromechanical technology, assure the
following functions:
v detection of presence or absence,
v detection of position.
Actuation of the operator (plunger or lever) on the miniature snap switch causes the electrical contact
to change state. This information can then be processed by a PLC controlling the installation.
OsiSense XC miniature snap switches can be used both in industrial applications and the
building sector.
Features
b OsiSense XC miniature snap switches incorporate a CO snap action, single break, contact.
They are characterised by:
v high electrical ratings for their very small size,
v short tripping travel,
v low tripping force,
v high repeat accuracy on the tripping points,
v long service life.
Terminology
Forces
b Maximum tripping force:
maximum force which must be applied to the operator to move it from the rest (unactuated)
position to the trip position (tripping point).
b Minimum release force:
value to which the force on the operator must be reduced to allow the snap action mechanism
to return to its rest (unactuated) position.
b Maximum permissible end of travel force:
maximum force that can be applied to the operator at the end of its travel without damaging
the switch.
Position/Travel
1 Tripping point: position of the operator in relation to the switch xings (xing hole centre line)
at the instant the switch contact changes state.
A Dierential travel: distance between the tripping point and the position at which the snap
action mechanism returns to its initial state on release of the operator.
2 Overtravel limit: position of the operator when an extreme force has moved it to the eective
end of its available travel.
B Overtravel: distance between the tripping point and the overtravel limit.
The reference point for the gures given for forces and travel is a point F, which is situated on the
plunger in the case of a basic switch or at 3 mm from the end of the plain lever in the case of a
lever operated switch.
Mechanical characteristics
Changeover time
b This is the time taken by the moving contact when moving from one xed contact to another
until it becomes fully stable (contact bounce included).
b This time is related to the inter-contact distance, the mechanical characteristics of the snap
action mechanism and the mass of the moving element. However, due to the snap action
mechanisms used, the time is largely independent to the speed of operation. It is normally
less than 20 milliseconds (including bounce times of less than 5 ms).
T1: bounce time
T: changeover time
Operating speed and maximum usable operating rate
ABC
b Our miniature snap switches are suitable for a wide range of operating speeds: generally,
from 1 mm/mn to 1 m/s.
b The maximum usable operating rate on a light electrical load may be as high as
10 operations/second.
Mounting
Mounting and operation
b To conform to the leakage paths and air gaps in standards EEC 24 - EN/IEC 61058 -
EN/IEC 60947:
v an insulation pad must be inserted between the snap switch and the xing surface if the latter
is metal.
v manual operation of a metal actuator must only be carried out with the aid of an intermediate
actuator made of an insulating material.
b The installer must ensure adequate protection against direct contact with the output terminals.
ABC
Actuation method
b Direct operation:
v the plunger should preferably be actuated along its axis. However, the majority of our
miniature snap switches will accept skewed operation provided the angle of actuation is not
more than 45°.
The travel of the actuator must not be limited to only reaching the tripping point. The actuator
must always be operated in such a manner so that the plunger reaches a point at least
0.5 times the stated overtravel value of the switch. Steps must also be taken to ensure that it
does not reach its end of travel nor exceed the maximum permissible end of travel force.
Presentation,
terminology,
characteristics,
mounting
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