data for Safety Switches0 pages

SWITCHES
ACCORDING TO IEC 60 947-3.
SWITCH

PROTECTION AGAINST OVERVOLTAGE

A mechanical switching device capable of making, carrying
and breaking currents under normal circuit conditions
which may include specified operating overload conditions
and also carrying for a specified time currents under specified abnormal circuit conditions such as those of short
circuit.
Note: A switch may be capable of making, but not breaking, short-circuit currents.

Uimp (Impulse withstand voltage) defines the device’s use
in abnormal network conditions with overvoltage due to
lightning on overhead wires etc.
This characteristic also defines the device’s dielectric
quality.
Overvoltage protection is ensured by choosing the equipment according to Uimp. The 4 impulse withstand categories of use at 400V/ 690V (IEC 60 364-4-44) are:

DISCONNECTOR

Category
1

Uimp
2,5 kV

Applications
specially protected equipment

2

4 kV

Portable tools, motors, etc.

3

6 kV

Equipment placed in
distribution networks

4

8 kV

Equipment placed at the head
of an installation.

A mechanical switching device which, in the open position,
complies with the requirements specified for the isolating
function.
Disconnector: (working definition) device without on-load
making and breaking capacity.

SWITCH DISCONNECTOR / LOAD BREAK SWITCH
A switch capable of making, carrying and breaking currents under normal circuit conditions and which, in the
open position, complies with the isolating requirements
specified for a disconnector.

SWITCH DISCONNECTOR FUSE
A switch-disconnector in which one or more poles have a
fuse in series in a composite unit.

The Uimp rating for most of the Katko switches is 8kV.
OPERATING TEMPERATURE
The normal operating temperature for Katko switches
is in the range -40 to +80°C. For higher ambient
temperatures than +40°C the maximum load of the
switch might be derated. For the right application, please
contact KATKO for further information.

UTILIZATION CATEGORY
CONFORMITY TO STANDARDS
Utilization
category

Use / Application

AC-20

Connecting and disconnecting under
no-load.

AC-21

Switching of resistive loads including
moderate overloads

AC-22

Switching of mixed loads, inductive and
resistive loads including moderate
overloads

AC-23

Switching of motor loads or other highly
inductive loads

10

Katko switches are designed to comply with both national
and international standards.
-Switches tested acc. to IEC 60 947
-AC 23 / 690V ratings
-50 kA R.M.S values
-CB certificates
-UL, CUL listed (UL 508)
-Fuse holder acc. to IEC 60 269 / UL512

Data subject to change without notice