Switching Resistive Loads - Siemens SIRIUS 3RT Manual

Configuration

6.6 Switching resistive loads

6.6 Switching resistive loads
Applications
The following contactor versions can be used to switch resistive loads according to utilization
category AC-1:
● 3-pole 3RT20 contactors (sizes S00 to S3)
● 4-pole 3RT23 contactors (sizes S00 to S3)
● 3-pole 3RT24 contactors (size S3) and 3RT14 (size S6 to S12)
These contactors feature 3 / 4 NO contacts as their main contacts.
Typical applications:
● Switching resistive loads
● Isolation of systems with ungrounded or poorly grounded neutral conductors.
● System switchover, where alternative AC power supplies are present.
● For inductive loads as contactors which conduct the current but do not have to perform
switching (e.g. if used in the vicinity of frequency converters).
● Switching mixed loads in distribution systems.
Configuration note
The 3RT10 contactor series for switching motors also has utilization category AC-1.
However, the 3RT14 AC-1 contactor is the more cost-effective alternative for this special
application.
Versions
The device bases are identical within each device size. In size S0, the installation depth for
contactors with a DC solenoid system is 10 mm larger than that for versions with an AC
solenoid system. Within the respective size (S2 to S12) all operating mechanism types have
the same installation depth.
100
SIRIUS - SIRIUS 3RT Contactors/Contactor assemblies
Manual, 09/2017, A5E03656507120A/RS-AE/006