40
Instruction Booklet
IB 33-790-1J
Effective November 2010
Instructions for Low Voltage Power
Circuit Breakers Types DS and DSL
EaToN CorPoraTIoN www.eaton.com
6.2 STATIONARY CONTACT SUB-ASSEMBLIES
The stationary contact sub-assemblies may be seen in
Figures 47, 48, 49, 51, and 53. All main contacts, i.e.:
those which carry the main continuous load current, are
of the butt type composed of a multiplicity of fingers.
Each finger is hinged at the upper end under controlled
pressure. Compression springs at the lower end apply
predetermined pressure against the moving main contact
in closing, and standing in the closed position. These
springs are visible in the photograph of the DS206 only.
With this construction, the pressure on the main contact
surfaces is increased during the carrying and opening of
high short circuit currents because the magnetic field of
the current pushes the lower end of the finger toward the
moving contact. Hinging the finger at the top thus results
in what is sometimes called “blow-on” action. This greatly
increases the capability of the entire contact assembly to
withstand the high fault currents associated with these
breaker ratings.
The stationary arcing contacts are similar for all ratings
and consist of two parallel fingers, one on each side of
the stationary terminal member. They are pushed toward
each other by compression springs and have arc resist-
ing tips.
Fig. 35 Three-pole Assembly of DS-632 Pole Units on Frame.
