SIEMENS
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Siemens IC 10 · 2017
Overload Relays
General data
7
✓
Available
--
Not available
1)
Exception: up to size S3, only stand-alone installation is possible.
2)
Alternatively available for screw terminals.
Features
3RU21
3RB30/3RB31
3RB20/3RB21
3RB22/3RB23
3RB24
Benefits
Design of load feeders
Short-circuit
strength up to
100 kA at 690 V
(in conjunction with
the corresponding
fuses or the
corresponding motor
starter protector)
✓
✓
✓
✓
✓
• Provides optimum protection of the loads
and operating personnel in the event of
short circuits due to insulation faults or faulty
switching operations
Electrical and
mechanical
matching to
3RT contactors
✓
✓
✓
✓
1)
✓
1)
• Simplifies configuration
• Reduces wiring outlay and costs
• Enables stand-alone installation as well as
space-saving direct mounting
Straight-through
transformers for
main circuit
2)
(in this case the
cables are routed
through the feed-
through openings of
the overload relay
and connected
directly to the box
terminals of the
contactor)
--
✓
(S2, S3)
✓
(S6)
✓
(S00 ... S6)
✓
(S00 ... S6)
• Reduces the contact resistance (only one
point of contact)
• Saves wiring costs (easy, no need for tools,
and fast)
• Saves material costs
• Reduces installation costs
Spring-type
connection system
for main circuit
2)
✓
(S00, S0)
✓
(S00, S0)
--
--
--
• Enables fast connections
• Permits vibration-resistant connections
• Enables maintenance-free connections
Spring-type
connection system
for auxiliary
circuits
2)
✓
✓
✓
✓
✓
• Enables fast connections
• Permits vibration-resistant connections
• Enables maintenance-free connections
Full starter
functionality
through IO-Link
--
--
--
--
✓
•
Enables in combination with the SIRIUS 3RT
contactors the assembly of communication-
capable motor starters
(direct-on-line, reversing and star-delta
(wye-delta) starting)
Starter function
--
--
--
--
✓
• Integration of feeders via IO-Link in the
control system up to 630 A or 820 A
© Siemens AG 2016