Switching Motorized Loads - Siemens SIRIUS 3RT Series System Manual

2.4.4

Switching motorized loads

Applications
3RT20 3-pole motor contactors can be used to switch three-phase motors. These contactors
feature 3 NO contacts as their main contacts.
Versions
The entire performance range of 3 to 18.5 kW/400 V (utilization category AC-3) is covered by
two sizes, S00 and S0, each with a width of 45 mm. The contactors of sizes S00 and S0 are
equipped with AC or DC magnet systems. Contactors of size S0 can also be supplied in a
UC drive version. The device floor areas are the same for all drive types. In size S0, the
installation depth for contactors with DC and UC magnet systems is 10 mm larger than that
for versions with an AC magnet system.
Connection to the automation level
3RA27 function modules can be mounted on the front of 3RT20 power contactors, thus
providing additional functionalities (e.g. star-delta (wye-delta) functionality) and enabling a
connection to be established with a control via IO-Link or AS-Interface. If 3RA27 function
modules are used, special versions of the 3RT2 power contactors (3RT2...-....-0CC0 as the
13th to 16th digits of the order number) must be used, which facilitate direct voltage tapping
of the main current paths. These communication-capable power contactors are supplied with
a 24 V DC drive option. The coil is controlled via the function module.
Rated powers
A single size covers several versions with different standard motor ratings. The specified
power (in kW) refers to the output power on the motor shaft (in accordance with the motor's
nameplate). The performance range of the 3RT20 3-pole power contactors in size S00
extends up to 7.5 kW at a voltage of 400 V. In size S0, the maximum power value is 18.5 kW
at a voltage of 400 V. All specified rated powers and rated currents refer to an ambient
temperature of 60 °C.
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
SIRIUS 3RT2 contactors/contactor assemblies
2.4 Configuration
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