Overload Protection Function - Siemens SIRIUS 3RA6 System Manual

5.3.2

Overload protection function

Overload protection function, phase loss protection
The 3RA61/3RA62 compact starter protects three-phase motors against overload. In
addition, the compact starter is provided with phase loss protection to prevent excessive
heating of the load in single phasing if phase loss occurs. In both cases, the compact starter
switches off without opening the breaker latching mechanism.
When operating with single-phase loads, the phase loss protection must be compensated to
prevent premature tripping. This is done by selecting the setting current I
starter higher than the motor operating current by a factor of 1.6.
Operator controls
The following operator elements are available to you on the compact starter to guarantee
optimal overload protection:
● "Current setting I
"Setting current I
● "Manual/auto reset" selector switch: Use the "Manual/auto reset selector switch" to
determine how the compact starter is reset after an overload trip.
– Manual reset "M": You must reset the compact starter manually using the blue reset
– Auto reset "A": The compact starter resets itself autonomously after approximately
● "Overload trip class" selector switch: For selecting trip CLASS 10E or CLASS 20E.
SIRIUS 3RA6 compact starter
System Manual, 09/2014, NEB560060102000/RS-AA/006
" setting wheel: Set the rated operating current of the load on the
e
" setting wheel.
e
button.
3 minutes. If there is voltage on A1/A2 at this point, the compact starter switches on
again. Manual reset using the blue reset button is possible in this setting after just
10 seconds.
WARNING
Automatic machine restart!
If the "A1/A2" LED lights up after an overload trip and a manual reset or auto reset is
performed, the machine will start up immediately. People may be injured if they stay
in the danger area of the machine.
Make sure that the danger area of the machine is kept clear of people.
3RA61/3RA62 compact starter
5.3 Functions
on the compact
e
57