
Thermal Overcurrent Circuit Breakers
Issue C
11
1
O
%
Germany (0 91 87) 10-0 - USA (847) 827-7600 - UK (01296) 420336 - www.etacbe.com
Single and multi pole
thermal circuit breakers (CBEs)
with and without auxiliary contacts
Max. voltage ratings 3 AC 415 V,
AC 250 V, DC 50 V
0.05 ... 30 A
Current ratings
With simple operation through the heating effect of current,
thermal circuit breakers offer one of the most reliable and
cost effective forms of protection device available. As a
result they are ideally suited to the protection of a broad
range of components and systems - from motors and
transformer windings, through printed circuit boards, to
the low voltage power distribution circuits of road vehicles,
boats, and battery powered machines.
Such applications all require the ability to discriminate
between safe switch-on surges or transients on the one
hand, and harmful sustained overloads on the other.
Thermal circuit breakers can withstand high level surges,
which arise from lamp loads or motor starting, for example.
At the same time they afford protection against the effects
of genuine failure such as motor locked rotors. The
characteristics of thermal CBE’s can be matched closely
to the ratings of the component or system they are
protecting, eliminating the need for over-sizing of wiring
and connectors, whilst offering dependable protection -
even under low level overcurrent conditions which can-
not be adequately provided for by other methods of
circuit protection.
E-T-A thermal circuit breakers utilise one of three different
mechanisms optimised for their range of operation
G
a snap action disc type bimetal and contact assembly
G
a bimetal with a mechanical latch and separate spring
loaded contact
G
a hot wire design with extremely fast switching time
All are individually calibrated in the factory to ensure safe,
predictable performance under a wide range of conditions.
The E-T-A thermal circuit breakers in this catalogue
section are manually resettable enabling the power supply
to be restored after operation. Several models combine
the functions of circuit breaker protection and on/off
switching in a single component. There is a choice of
rocker, toggle or push button actuation according to user
preference.
E-T-A’s wide range of models enables the designer to
make optimal selections according to specific
performance, installation and styling needs.
All dimensions without tolerances are for reference only. In the interest of improved design,
performance and cost effectiveness the right to make changes in these specifications without
notice is reserved. Product markings may not be exactly as the ordering codes.