User Guide

3RT1 contactors/ 3RH1 control relays
SIRIUS System Manual
GWA 4NEB 430 0999-02 DS 01
3-35
3.3 Application and areas of use
Various switching devices are available for switching electrical loads. The
contactor is the most suitable device for frequent switching operations.
Contactors are the most commonly used switching device in industry,
mechanical engineering and in switchgear and controlgear. Due to the
increased automation in manufacturing, contactors have become more
important. This has also increased the variety of loads that must be con-
trolled.
Automated production systems are considerably more sensitive to opera-
tional malfunctions than manually operated systems. Each fault on an elec-
trical device means downtime, waste, loss of production, and investment in
order to get the system up and running again.
For this reason, we concentrated on high reliability when developing the
SIRIUS contactor range. This includes, increased service life, high contact
reliability, and the possibility to use the contactors at higher ambient tem-
peratures in the enclosure. It is possible to use the contactors up to 60 °C
without derating when the devices are installed in a row.
To deal with the variety of possible applications, there are also contactor
variants for special applications, such as for switching resistive loads or
capacitors. This is in addition to the main 3RT10 range of contactors for
switching motors.
The different contactor ranges and their possible applications are described
in the following subsections.
3.3.1 3RT10 contactors with 3 main contacts for switching motors
Field of application The 3-pole 3RT10 contactors use 3 NO contacts as main contacts. They are
mainly used to switch three-phase induction motors.
Frame sizes The full performance range from 3 to 250 kW/400 V (utilization categories
AC-2 and AC-3) (up to 400 HP/460 V UL508) is covered by 7 frame sizes.
The frame sizes cover most of the standard motor outputs.
Dimensions The contactors are provided with alternating or direct current magnetic sys-
tems. The required panel areas of the devices of the two operating mecha-
nism types are the same. For frame sizes S0 to S3, the installation depth for
contactors with the DC magnet system is between 10 mm and 15 mm
greater than for the variants with the AC magnet system.
Power ratings All the specified power and current ratings apply to an ambient temperature
of 60 °C without derating.
For use at increased ambient temperatures see section 3.2.4.4 "Ambient
temperature".
Increasing the power The ease of expansion is an advantage for configuration. In many applica-
tions there is enough space to retrofit the contactor with the next higher rat-
ing class and thus increase motor output.