Description
2.5 Protection functions
3VA molded case circuit breakers with UL and IEC certification
72 Manual, 01/2019, L1V30435333-01
Measurement method 2: Direct detection
In this case, an external current transformer is installed directly in the grounded neutral point
of the transformer. When the set ground-fault current is reached, a message is directly
output (ETU556 and ETU856) or the circuit breaker is tripped (ETU560 and ETU860).
This measuring method must be activated explicitly in the ETU: On the display under menu
item "GF M", switch over from "rES" (measurement method 1) to "d Ir" (measurement
method 2).
3-pole molded case circuit breaker, external current transformer in the grounded neutral
point of the transformer:
Trip unit variants, 3-pole 3VA6 molded case circuit breaker with external N transformer:
● ETUs 5-series: ETU556 (LSIG alarm), ETU560 (LSIG)
● ETUs 8-series: ETU856 (LSIG alarm), ETU860 (LSIG)
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