3RA61/3RA62 compact starter
5.3 Functions
SIRIUS 3RA6 compact starter
System Manual, 09/2014, NEB560060102000/RS-AA/006
59
5.3.3
Short-circuit protection function
Short-circuit protection function
The compact starter has two short-circuit releases:
●
a non-delayed overcurrent release and
●
a short-time delayed overcurrent release.
In the case of the non-delayed overcurrent release, the tripping current is 14 times the value
of the maximum rated operating current I
e
. It responds quickly in the case of high short-circuit
currents.
Note
Tripping current
In the case of compact starters with I
e
= 0.4 A, I
e
= 1.25 A and I
e
= 4 A, the tripping current is
56 A.
In the case of compact starters with I
e
= 12 A, the tripping current is 168 A.
In the case of compact starters with I
e
= 32 A, the tripping current is 448 A.
In the case of the short-time delayed overcurrent release, the tripping current is 12 times the
set overload current. This overcurrent release thus depends on the set overload current and
can be modified using this value. The short-time delayed overcurrent release responds to
low short-circuit currents.
The compact starter has a short-circuit breaking capacity I
CS
of 53 kA at a voltage of
400 V AC.
Overload trips and short-circuit trips are signaled via two separate signaling contacts so that
both signals can be evaluated in their own right. For additional information on terminal
assignment, please refer to "Connection (Page 72)".
Display concept
The "Short circuit tripped" status is indicated by the following elements:
Table 5- 7
Short circuit trip display elements (direct starter/reversing starter)
Actuator
Mech. display
RLT 0%
Compact starter status
TRIPPED
No display
Short circuit tripped
