User Guide

3RT1 contactors/ 3RH1 control relays
SIRIUS System Manual
GWA 4NEB 430 0999-02 DS 01
3-33
Constant operation at
an ambient tempera-
ture of Tu > 60 °C
The constant operation of the 3RT10 contactors at an ambient temperature
of
Tu > 60 ° C is possible under the following guidelines.
Mounting For better heat dissipation for contactors without side-mounted auxiliary
contacts they should be mounted with a minimum 10 mm clearance when
mounting side by side.
The following declarations are based on this clearance distance.
Thermal load carrying
capacity of the main cir-
cuit
The standard contactors are designed for a max. ambient temperature of
Tu = 6 0 ° C .
For use of the contactors at higher ambient temperatures up to max. 70 °C,
then the normal rated operational current Ie/AC-1 (or Ie/DC-1) and the oper-
ating frequency must be reduced.
The following calculations can be used:
Ie
max., Tu
= the calculated rated current of the contactor at
increased ambient temperature
Ie/ AC-1 bzw. Ie/ DC-1 = Rated current of the contactor at the particular
utilization category and Tu ≤ 60 °C
Tu= Actual ambient temperature at Tu > 60 °C
Coil voltage tolerance So that the contactor coil isn’t thermally overloaded with the increased
ambient temperature, the voltage tolerance of the rated coil voltage Us
needs to be limited according to the Table.
Ie
max.,Tu
= Ie/AC - 1 •
60°C
Tu
Ie
max.,Tu
= Ie/DC - 1 •
60°C
Tu
z
max.,Tu
= z •
60°C
Tu
Tu S00 S0 to S3
60 °C 0.85 to 1.1 Us 0.8 to 1.1 Us
70 °C 0.85 to 1.0 Us 0.8 to 1.0 Us
Table 3-12: Coil voltage tolerance