Siemens SIRIUS 3RA

The response limits of the short-circuit release always refer to the maximum setting value:
• In the case of motor starter protector A, the response value of the short-circuit release is
208 A (13 × 16 A).
At the setting value of 15 A, the distance to the response limit of the short-circuit release is
13.86 times the current setting (208 A / 15 A =13.86).
• In the case of motor starter protector B, the response value of the short-circuit release is 260 A
(13 × 20 A). With a setting value of 15 A, the distance to the response limit of the short-circuit
release is 17.33 times the current setting (260 A / 15 A = 17.33).
In the present example, the distance to the response limit of 13.86 times the setting current for
motor starter protector A increases to 17.33 times the current setting for motor starter
protector B.
6.2.3 Technical modi󹪝cations/restrictions of 3RV2 motor starter protectors
Restriction of the maximum starting current is necessary for one setting range each of sizes S0,
S2 and S3.
The reason for this lies in the corresponding variants' making and breaking capacities.
3RV2 motor starter pro‐
tectors
3RV2.21-4E... 3RV2.3.-4R... 3RV2.4.-4M...
Setting range for over‐
load release
27 to 32 A 70 to 80 A 80 ... 100 A
Reduced starting current
ratio
8 times 9 times 7.8 times
Max. permissible starting
current
32 A x 8 = 256 A 80 A x 9 = 720 A 100 A x 7.8 = 780 A
Starting current ratio:
Maximum permissible rated operational current [A]
3RV2.21-4E... 3RV2.3.-4R... 3RV2.4.-4M...
≤ 8 times 32.0 80.0 97.5 A
8.5 times 30.2 80.0 91.8 A
9 times 28.4 80.0 86.6 A
9.5 times 27.0 75.8 82.1 A
10 times - 72.0 --
Note
For size S0, the setting range variants "-4P" (30 to 36 A) and "-4F" (34 to 40 A) are not suitable
for use with IE3 motors.
We recommend the use of size S2 for these current ranges.
Con󹪝guration
6.2 Use of 3RA2 load feeders with highly energy-e󹪟cient motors (IE3)
SIRIUS 3RA Load Feeders
30 Equipment Manual, 02/2022, A5E03656507520A/RS-AC/004