SIRIUS 3RU2/3RB3 overload relays
5.10 Technical data
SIRIUS Innovations
536 System Manual, 01/2011, A8E56203870002-03
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 Description 3RU21 3RB30/3RB31
Sizes
ï‚· Are matched to the dimensions,
connections and technical features of the
other devices in the SIRIUS modular
system (contactors, soft starters, etc.)
ï‚· Permit the mounting of slim-line and
compact load feeders in widths of 45 mm
(S00), 45 mm (S0)
ï‚· Make configuration easier
S00/S0 S00/S0
Seamless current range
ï‚· Allows straightforward and consistent
configuration with one series of overload
relays (for small to large loads)
0.11 to 40 A 0.1 to 40 A
5.10.1.2 Protection functions - overview
Table 5- 34 Protection functions supported by 3RU21 and 3RB20/3RB31 overload relays
Feature Description 3RU21 3RB30/3RB
31
Tripping in the event of overload
ï‚· Provides optimum current-dependent protection of
loads against impermissibly high temperature rise
due to overload
✓ ✓
Tripping in the event of phase
asymmetry
ï‚· Provides optimum current-dependent protection of
loads against impermissibly high temperature rise
due to phase asymmetry
✓ ✓
Tripping in the event of phase failure
ï‚· Minimizes the temperature rise of the three-phase
motor in the event of a phase failure
✓ ✓
Protection of single-phase loads
ï‚· Enables single-phase loads to be protected
✓ --
Tripping in the event of ground fault
by means of
internal ground-fault detection (can
be activated)
ï‚· Provides optimum protection of loads in the event
of high-impedance faults to ground caused by
moisture, condensation, damaged insulation, etc.
ï‚· Eliminates the need for additional special
equipemnt
ï‚· Saves space in the control cabinet
ï‚· Reduces wiring outlay and costs
-- ✓
(3RB31
only)