Description
2.5 Standards and guidelines
3VA molded case circuit breakers
64
Manual, 04/2015, A5E03603177010-02
2.5.6
Safety clearances
During a short-circuit interruption, high temperatures, ionized gases and high pressures
occur in and above the arcing chambers of the molded case circuit breaker.
Safety clearances are required to:
●
allow pressure distribution
●
prevent fire or damage caused by any diffused ionized gases
●
prevent a flashover to grounded parts
●
prevent arcing or short-circuit currents to live sections.
The following safety clearances apply to 3VA molded case circuit breakers:
①
Molded case circuit breaker without accessories or with short terminal cover
②
Molded case circuit breaker with accessories, e.g. phase barrier or long terminal cover
A
Minimum clearance between molded case circuit breaker and current paths (uninsulated and
grounded metal), see tables below
B
Minimum clearance between molded case circuit breaker and side walls left / right (uninsulated
and grounded metal), see tables below
C
Minimum clearance between two horizontally installed molded case circuit breakers, see tables
below;
applicable to fixed-mounted and plug-in versions (see chapter Plug-in and draw-out technology
(Page 201))
D
Minimum clearance between molded case circuit breaker and control cabinet door
E
Minimum clearance between live parts of connection system and grounded mounting plate
Summary of Contents for 3VA1 100 A
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Page 518: ...Conversion tables 3VA molded case circuit breakers 518 Manual 04 2015 A5E03603177010 02 ...
Page 531: ...Index 3VA molded case circuit breakers Manual 04 2015 A5E03603177010 02 531 ...
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