Siemens SIRIUS 3RT Series System Manual page 119

Ambient temperature
The 3RT2 contactors are dimensioned as standard for operation at ambient temperatures of
between -25 °C and +60 °C. Up to 60 °C, side-by-side mounting can be used without any
restriction. The devices can be stored at temperatures within the range from
-55 °C to +80 °C.
Size S00 and S0 contactors can be used at higher ambient temperatures, but various
constraints must be considered. The 3RT20 contactors can be operated continuously at an
ambient temperature of Ta > 60 °C, taking the following points into account:
Thermal load capacity of the main current paths
The standard contactors are dimensioned for a maximum ambient temperature of
Ta = 60 °C. In order to use the contactors at higher ambient temperatures of up to 70 °C, the
rated operational current I
The following linear dependencies can be applied here:
I max., Ta =
e
I /AC-1 or I
e
Ta =
The contactors may be operated for 1 hour at an ambient temperature of up to Ta ≤ 80 °C
without reducing the permissible currents. Nevertheless, the average ambient temperature
must not exceed Ta ≤ 60 °C for any 24 hour period. Note, however, that contactors which
contain electronic components or which are combined with electronic accessories
(e.g. integrated overvoltage attenuation, etc.) may only be operated at an ambient
temperature of up to Ta ≤ 60 °C.
Minimum clearances from adjacent components
The 3RT2 contactors are dimensioned for side-by-side mounting at temperatures of up to
+60 °C. At higher temperatures a clearance of 10 mm may be required in order to ensure
better heat dissipation with side-by-side mounting.
Operating range of the contactor drive
All SIRIUS contactors comply with the operating range limits of 0.85 to 1.1 x U
control supply voltage) stipulated in standard IEC EN 60947. The majority of the devices
feature an operating range of 0.8 to 1.1 x U
Reference
More information ...
About minimum clearances from adjacent
components and the operating range of the
contactor drive
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
/AC-1 or I
e
Rated operational current of the contactor at increased ambient
temperature, to be calculated
/DC-1 = Rated operational current of the contactor for relevant utilization category
e
and Ta ≤ 60 °C
Actual ambient temperature Tua > 60 °C
SIRIUS 3RT2 contactors/contactor assemblies
/DC-1 and the switching frequency z must be reduced.
e
, on some versions it is 0.7 to 1.3 x U
S
Can be found in the chapter titled ...
Technical data (Page 228)
2.4 Configuration
(rated
S
.
S
119