Applications
3.3 Use of the 3VA UL molded case circuit breaker as a molded case switch (MCS)
3VA molded case circuit breakers with UL and IEC certification
138
Manual, 01/2019, L1V30435333-01
3.3
Use of the 3VA UL molded case circuit breaker as a molded case
switch (MCS)
Molded case switches are used as:
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Disconnectors in subdistribution and final distribution boards
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Bus couplers
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Disconnectors for machine groups, e.g. as maintenance and repair breakers
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Operator control and disconnector element for cables, busbars and device groups
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Application as mains supply disconnectors
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Application as main switches
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Isolation of small distribution systems in industrial/commercial buildings
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Disconnection of loads
Molded case switches can be used to switch equipment and parts of electrical installations
up to their rated current and rated voltage.
In contrast to the switch disconnector according to IEC 60947-3, the molded case switch has
a short-circuit release for self-protection up to a specified maximum short-circuit current and
is certified to UL 489. The special advantage of the molded case switch is that the type of
protective device in the upstream panelboard up to the specified short-circuit current of the
molded case switch is insignificant.
So that the molded case switches of the 3VA UL series can also be used globally in
IEC applications, they are also approved as CBI-X according to IEC 60947-2 Annex L.
Depending on the requirement, the range of 3VA UL molded case switches includes devices
for a short-circuit current of 65 kA as well as 100 kA at 480 V according to UL 489.
