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• Short-Time Withstand Current Test (Short-Circuit Withstand Capacity) to IEC/EN 60947-7-1
Apart from the rated current which can be constantly applied to an electrical device, operation-related short peak currents consis-
tently occur in electrical installations; e.g., when motors are started. Also, in the event of a short-circuit, a high current can flow for
a short time until the fuse element melts. Terminal blocks and connecting devices must be able to withstand such conditions. The
short-time withstand capacity is defined in standards such as IEC/EN 60947-7-1 for through rail-mounted terminal blocks, as a
current-carrying capacity of 120A per mm² nominal diameter for the duration of 1 second.

The short-circuit current of the 95 mm²/
AWG 4/0 high-current terminal block
(item no. 285-195)
is 11400 A.

Test specimen

mV

During the short-time withstand current
Measuring Measuring test, the ground (earth) conductor rail-
point I CS I CC point mounted terminal blocks are subjected
three times for 1s each to a current load
of 120A/mm².
V CC The pass criterion for the test is the volt-
age drop (limit value and constancy).

V CS

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Measuring
point