Техническая Спецификация для Pizzato Elettrica Microswitch 250 Vac 6 A IP40 momentary 10 pc(s) MKV11D30
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Модели
MKV11D30
2D
General Catalog 2011-2012
2/125
Microswitches for safety applications
All microswitches that have the symbol beside the code are with positive opening,
therefore suitable for safety applications.
These microswitches are provided with a rigid connection between push button and NC
contacts, which are opened by force through a strong/sturdy internal safety lever.
The positive opening has been realised in conformity with the standard IEC 60947-5-1,
enclosure K, therefore these microswitches are suitable for the installation for people’s
protection.
Contact block reliability
In the following table we refer to the typical microswitch contact structure (type A) normally used in the industry, compared with the innovative
solution that Pizzato Elettrica uses in new MK series microswitches: movable contact with single interruption and double contacts (type B).
As you can see from the table below, this last structure (type B) offers half of the contact resistance ( R) than the simple mobile contact (type
A) and a lower probability of failure ( fe).
In fact, defined x the probability of a commutation failure of a single interruption, it results that in the type A the failure probability fe=x, in the
type B the probability fe= x
2
. This means that if in a certain situation the failure probability x is equal, for instance, to 1 x 10
-4
(1 failed interruption
every 10.000), we will have:
- in type A one failed commutation every 10.000
- in type B one failed commutation every 100.000.000
Microswitches of MK series have been developed in order to add new features to traditional and tested
microswitches of Pizzato Elettrica (cross-reference at page 7/50). These new products have been designed
with shapes and fixing perfectly interchangeable with the previous ones and with various additional functions
useful to extend the application field.
The main innovation of this series is the tripping device modern and evolved, with qualitative features higher
than solutions present on the market.
The electrical contact on new microswitch has been realized with higher reliability technology, thanks to the
double and redundant shape, and has the possibility to carry out operations with positive opening.
The housing of the new microswitch provides the possibility to seat gaskets in order to seal the device
against fine dusts or liquids up to IP65 degree.
Fastening terminals of conductors are more practical and allow the fixing of different diameter cables or
the possibility to choose different bends of faston contacts. For high quantity it’s possible to supply the
microswitch only with the contact NO or NC, in order to minimize purchase costs.
Introduction
Extended temperature range
On request, on new MK series are available the versions with extended temperature range. Differently from
standard MK microswitches with temperature range from +85 C° to -25 C°, these special versions can be
used in places where the ambient temperature changes from +85 C° to -40 °C.
They can be installed inside cold stores, sterilizers or other equipment with very low ambient temperature.
Special materials that have been used to realize these versions, maintain unchanged their features also in
these conditions, widening the installation possibilities.
Type
Figure
Description
Contact
resistance R
Probability of
failure fe
A
Common
microswitch
COMMON
NC
NO
Contacts
with single
interruption
R=Rc
fe=x
B
Pizzato
microswitch
MK series
NC
NO
COMMON
Contacts
with single
interruption and
double contacts
R=Rc/2
fe x
2
safety lever
Microswitches MK series