User Manual

SIRIUS 3RU2/3RB3 overload relays
5.2 Product description
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
487
Accessories
The accessories have been tailored to the overload relays; they can be mounted easily and
without the need for tools.
5.2.2 Versions
Sizes, setting ranges, and device versions
The table below provides an overview of the various sizes in which 3RU21 thermal overload
relays and 3RB30/3RB31 solid-state overload relays are available. The maximum rated
currents, the minimum and maximum setting ranges, and the available tripping classes are
listed for each individual size.
Table 5- 2 Sizes
Size
(width 45 mm each)
3RU21 thermal overload
relay
3RB30 solid-state overload
relay
3RB31 solid-state
overload relay
Rated operational voltage U
e
690 V AC 690 V AC 690 V AC
Rated frequency 50/60 Hz 50/60 Hz 50/60 Hz
Tripping classes CLASS 10 CLASS 10 or 20 (fixed) CLASS 5, 10, 20, 30
(adjustable)
Current ranges
for thermal overload releases
0.11 to 0.16 A
to
34 to 40 A
- -
Current ranges
for solid-state overload releases
- 0.1 to 0.4 A
to
10 to 40 A
0.1 to 0.4 A
to
10 to 40 A
Rated operational power for three-
phase motors at 400 V AC
0.04 kW
to
18.5 kW
0.04 kW
to
18.5 kW
0.04 kW
to
18.5 kW
3RB30/3RB31 solid-state overload relays have the same dimensions as 3RU21 thermal
overload relays. This means that thermal overload relays can easily be substituted with solid-
state versions if increased overload protection is required (wide setting ranges (1:4), for
example, or even reduced power loss and, as a result, minimized energy consumption).