Technical Data; Performance Features; General Data; Protection Functions - Overview - Siemens SIRIUS 3RT Series System Manual

SIRIUS 3RU2/3RB3 overload relays

5.10 Technical data

5.10 Technical data
5.10.1

Performance features

5.10.1.1

General data

Table 5- 33 General data for 3RU21 and 3RB30/3RB31 overload relays
Feature
Sizes
Seamless current range
5.10.1.2

Protection functions - overview

Table 5- 34 Protection functions supported by 3RU21 and 3RB20/3RB31 overload relays
Feature
Tripping in the event of overload
Tripping in the event of phase
asymmetry
Tripping in the event of phase failure
Protection of single-phase loads
Tripping in the event of ground fault
by means of
internal ground-fault detection (can
be activated)
536
Description
Are matched to the dimensions,

connections and technical features of the
other devices in the SIRIUS modular
system (contactors, soft starters, etc.)
Permit the mounting of slim-line and

compact load feeders in widths of 45 mm
(S00), 45 mm (S0)
Make configuration easier

Allows straightforward and consistent

configuration with one series of overload
relays (for small to large loads)
Description
Provides optimum current-dependent protection of

loads against impermissibly high temperature rise
due to overload
Provides optimum current-dependent protection of

loads against impermissibly high temperature rise
due to phase asymmetry
Minimizes the temperature rise of the three-phase

motor in the event of a phase failure
Enables single-phase loads to be protected

Provides optimum protection of loads in the event

of high-impedance faults to ground caused by
moisture, condensation, damaged insulation, etc.
Eliminates the need for additional special

equipemnt
Saves space in the control cabinet

Reduces wiring outlay and costs

3RU21 3RB30/3RB31
S00/S0 S00/S0
0.11 to 40 A 0.1 to 40 A
3RU21
✓
✓
✓
✓
--
System Manual, 01/2011, A8E56203870002-03
3RB30/3RB
31
✓
✓
✓
--
✓
(3RB31
only)
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