Siemens SIRIUS 3RU - Page 78

Configuration
6.6 Application environment
SIRIUS 3RU thermal overload relays / SIRIUS 3RB electronic overload relays
78 Manual, 09/2016, A5E03656507420A/RS-AB/003
Ambient temperatures for the 3RB20 / 3RB21 and 3RB30 / 3RB31 overload relays
3RB20 / 3RB21 and 3RB30 / 3RB31 electronic overload relays compensate temperature in
the temperature range from –25 °C to +60 °C in accordance with IEC/EN 60947-4-1.
The reduction factors that have to be taken into account when using electronic overload
relays at an ambient temperature higher than 60 °C can be obtained on request from our
Technical Assistance on the Internet (http://www.siemens.com/sirius/technical-assistance).
Current reduction in the case of heavy starting for 3RB20 / 3RB21 and 3RB30 / 3RB31 overload
relays
For the 3RB20 and 3RB21 electronic overload relays with the sizes S6 and S10 / S12, the
upper set value of the setting range must be reduced for ambient temperatures > 50 °C by a
certain factor in accordance with the following tables.
Table 6- 10 Ambient temperatures of 3RB20 / 3RB21 overload relays (sizes S6 and S10 / S12) - single installation
Article number
Setting range
Reduction factor for the upper set value applies to single
installation and an ambient temperature of ...
+ 50 °C
+ 60 °C
3RB2056 / 3RB2153
50 ... 200 A
100 %
100 %
3RB2066-1G
3RB2066-2G
3RB2163-4G
55 ... 250 A 100 % 100 %
3RB2066-1M
3RB2066-2M
3RB2163-4M
160 ... 630 A 100 % 90 %
Table 6- 11 Ambient temperatures of 3RB20 / 3RB21 overload relays (sizes S6 and S10 / S12) - contactor mounting
Article number
Setting range
Reduction factor for the upper set value applies to contactor
mounting and an ambient temperature of ...
+ 50 °C
+ 60 °C
3RB2056 / 3RB2153
50 ... 200 A
100 %
70 %
3RB2066-1G
3RB2066-2G
3RB2163-4G
55 ... 250 A 100 % 70 %
3RB2066-1M
3RB2066-2M
3RB2163-4M
160 ... 630 A 100 % 70 %
No reduction in the maximum permissible rated operating current is required for size S00 (to
16 A).