Siemens SIRIUS 3RT - Page 92

Configuration
6.4 Application environment
SIRIUS - SIRIUS 3RT Contactors/Contactor assemblies
92 Manual, 09/2017, A5E03656507120A/RS-AE/006
Using the S00, S0, S2 and S3 contactors at low ambient temperatures
The S00 to S3 contactors can be used at a minimum ambient temperature of T
a
= -50 °C, but
the mechanical durability will be reduced by up to 50 %. The other catalog data remains
unaffected. In such instances a high switching frequency and long duty cycle are preferable
to a low switching frequency and short duty cycle. Contactors which contain electronics or
which are combined with electronic accessories must not be used at temperatures below
T
a
=-40 °C.
Service life
Using the contactors at higher ambient temperatures places a greater stress on molded
parts, main current paths, and the solenoid coil. This reduces the mechanical durability and
shortens the service life of the contactors. The service life is primarily influenced by the ON
period. The table below shows the reduced mechanical durability and shortened service life
values:
Table 6- 1 Durability and service life of 3RT20 contactors
Ambient temperature T
a
Mechanical endurance
[x10
6
operating cycles]
Service life
[years]
S00
S0 … S3
S00 … S3
≤ 60 °C
30
10
20
65 °C
15
5
15
70 °C 3 1 10
The specifications for the service life apply to an ON period of 100 %.