Description
2.3 Technical details
3VA molded case circuit breakers with UL and IEC certification
48 Manual, 01/2019, L1V30435333-01
The term "current limitation" refers to the action of limiting the peak value of the prospective
impulse short-circuit current i
p
to a lower let-through current i
D
.
The compact design of the breakers has been made possible by their excellent current
limiting capabilities. In the event of a short circuit, the molded case circuit breaker
significantly reduces the magnitude of let-through current, i.e. it reduces the current loading
of downstream equipment (lower thermal load, fewer dynamic forces). The level of let-
through energy is also reduced to a considerable extent.
The 3VA UL molded case circuit breakers are designed as current-limiting molded case
circuit breakers; however, they do not have "current limiting certification" according to
UL 489.
Unlimited current
Peak value of limited current
Limited current
i
D
Let-through current
i
p
Unlimited impulse short-circuit current
t
a
Break time
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