Description; Insulated - Encased Construction - Siemens SBA 800 Information And Instruction Manual

Description

In addition to the performance achieved by combining the
MCCB and LVPCB technologies, several installation, opera-
tion, and safety features have been incorporated into the SB
breakers.

Insulated - Encased Construction

The SB breaker's housing, internal barrier, and front cover
are molded from a thermoset material with a high-dielectric
strength (electrical insulation). The one piece molded case
(base and housing) provides enhanced structural integrity. A
mid barrier provides outer wall reinforcement, integral arc
baffling, and insulation/isolation between the two compart-
ments of the circuit breaker. This patented construction has
allowed for a higher interrupting capacity within a smaller size
than could have been achieved by more conventional con-
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struction. The electrical insulation property of the thermoset
material enhances the safety of operation. The insulated case
physically isolates and electrically insulates the user from the
internal high voltage contacts.
The arc chambers and main contact structure are encased
in the back compartment. The trip unit, controls, springs of
the stored energy mechanism, and optional internal acces-
sories are located in the front compartment. Access to the
front compartment is by the removable front cover. Since the
barrier between the two compartments is made from the
same insulating thermoset material as the housing, the user
is physically isolated and electrically insulated from the main
breaker mechanism and contacts when the front cover is
removed.