Siemens SIRIUS 3RH Series - Switching Resistive Loads

SIRIUS 3RT2 contactors/contactor assemblies
2.4 Configuration
SIRIUS Innovations
124 System Manual, 01/2011, A8E56203870002-03
2.4.5 Switching resistive loads
Applications
The following contactor versions can be used to switch resistive loads:
3RT20 contactors with 3 NO contacts 3RT23 contactors with 4 NO contacts 3RT25 contactors with 2 NO contacts +
2 NC contacts
 Switching resistive loads (3-pole).
 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 resistive loads (4-pole).
 Isolation of systems with
ungrounded or poorly grounded
neutral conductors.
 System transfers if alternative AC
power supplies are present.
 For inductive loads as contactors
which conduct the current, but do
not have to perform switching. (For
example if used in the vicinity of
frequency converters).
 Switching mixed loads in
distribution systems (e.g. to supply
heaters, lamps, motors, PC power
supply units) with a cos ϕ value
> 0.8 according to IEC 60947-4-1
test conditions for utilization
category AC-1.
 Switching 2 separate 2-pole loads.
Note:
3RT25 contactors are not suitable for
switching a load between 2 current
sources.
Versions
The entire performance range of 18 to 50 A/up to 690 V (utilization category AC-1) is
covered by two sizes, S00 and S0, each with a width of 45 mm. All 3-pole 3RT20 contactors
and 4-pole 3RT23/3RT25 contactors of sizes S00 and S0 are equipped with AC or DC
magnet systems. The device floor areas are the same for all drive types. In size S0, the
installation depth for contactors with a DC magnet system is 10 mm larger than that for
versions with an AC magnet system.
Rated powers
A single size covers several versions with different rated operational currents I
e
.
The performance range of the 3-pole 3RT20 power contactors is exactly the same as that of
the 4-pole 3RT23 power contactors with 4 NO contacts. In size S00, the range extends up to
22 A at a voltage of up to 690 V. In size S0, the maximum current value is 50 A at a voltage
of up to 690 V.
The performance range of the 4-pole 3RT25 power contactors with 2 NO contacts and 2 NC
contacts in size S00 extends up to 22 A at a voltage of up to 690 V. In size S0, the maximum
current value is 40 A at a voltage of up to 690 V.
All specified rated powers and rated currents refer to an ambient temperature of 40 °C.