© Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
3RB22, 3RB23 for high-feature applications

■ Overview
The modular, solid-state overload relays with external power
supply type 3RB22 (with monostable auxiliary contacts) and
type 3RB23 (with bistable auxiliary contacts) up to 630 A (up to
820 A possible with a series transformer) have been designed
for inverse-time delayed protection of loads with normal and
1 heavy starting (see Technical Information LV 1 T, "Function")
against excessive temperature rises due to overload, phase
2 9 unbalance or phase failure. An overload, phase unbalance or
phase failure result in an increase of the motor current beyond
3 the set rated motor current. This current rise is detected by
5
means of a current measuring module and electronically evalu-
4 ated by a special evaluation module which is connected to it.
5 The evaluation electronics sends a signal to the auxiliary con-
6
tacts. The auxiliary contacts then switch off the load by means of
8 a contactor. The break time depends on the ratio between the
7
tripping current and current setting Ie and is stored in the form of
a long-term stable tripping characteristic (see Technical
Information LV 1 T, "Characteristic Curves"). The "tripped" status
is signaled by means of a continuous red "OVERLOAD" LED.
3RB22/3RB23 evaluation module The LED indicates imminent tripping of the relay due to overload,
(1) Green "READY" LED: phase unbalance or phase failure by flickering when the limit
A continuous green light signals that the device is working correctly. current has been violated. This warning can also be issued as a
(2) Red "GND FAULT" LED
signal through auxiliary contacts.
A continuous red light signals a ground-fault tripping. In addition to the described inverse-time delayed protection of
(3) Red "THERMISTOR" LED: loads against excessive temperature rises, the 3RB22/3RB23
A continuous red light signals an active thermistor trip. solid-state overload relays also allow direct temperature moni-
(4) Red "OVERLOAD" LED: toring of the motor windings (full motor protection) by connection
5

A continuous red light signals an active overload trip; a flickering red with broken-wire interlock of a PTC sensor circuit. With this tem-
light signals an imminent trip (overload warning). perature-dependent protection, the loads can be protected
(5) Motor current and trip class adjustment: against overheating caused indirectly by reduced coolant flow,
Setting the device to the motor current and to the required trip class for example, which cannot be detected by means of the current
dependent on the start-up conditions is easy with the two rotary alone. In the event of overheating, the devices switch off the con-
switches. tactor, and thus the load, by means of the auxiliary contacts. The
(6) Selector switch for manual/automatic RESET: "tripped" status is signaled by means of a continuously illumi-
With this switch you can choose between manual and automatic nated "THERMISTOR" LED.
RESET. To also protect the loads against high-resistance short-circuits
(7) Test/RESET button: due to damage to the insulation, humidity, condensed water,
Enables testing of all important device components and functions, etc., the 3RB22/3RB23 solid-state overload relays offer the pos-
plus resetting of the device after a trip when manual RESET is sibility of internal ground-fault detection in conjunction with a
selected.
function expansion module (for details see "Selection and order-
(8) Connecting terminals (removable joint block): ing data", not possible in conjunction with contactor assembly
The generously sized terminals permit connection of two conductors for Wye-Delta starting). In the event of a ground fault the
with different cross-sections for the auxiliary, control and sensor cir-
cuits. Connection is possible with screw connection and alternatively
3RB22/3RB23 relays trip instantaneously. The "tripped" status is
with spring-type connection. signaled by means of a continuous red "Ground Fault" LED. Sig-
naling through auxiliary contacts is also possible.
(9) 3RB29 85 function expansion module:
Enables more functions to be added, e. g. internal ground-fault detec- After tripping due to overload, phase unbalance, phase failure,
tion and/or an analog output with corresponding signals. thermistor or ground-fault tripping, the relay is reset manually or
automatically after the recovery time has elapsed (see
Technical Information LV 1 T, "Function").
In conjunction with a function expansion module the motor cur-
rent measured by the microprocessor can be output in the form
of an analog signal 4 ... 20 mA DC for operating rotary coil in-
struments or for feeding into analog inputs of programmable
logic controllers. With an additional AS-Interface analog module
the current values can also be transferred over the AS-i bus
system.
The devices are manufactured in accordance with environmen-
tal guidelines and contain environmentally friendly and reusable
materials.
They comply with all important worldwide standards and
approvals.

3RB29 06 current measuring module

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 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
3RB22, 3RB23 for high-feature applications
"Increased safety" type of protection EEx e according to
ATEX directive 94/9/EC ■ Application
The 3RB22 (monostable) solid-state overload relays are suitable Industries
for the overload protection of explosion-proof motors with "in- The 3RB22/3RB23 solid-state overload relays are suitable for
creased safety" type of protection EEx e. The relays meet the re- customers from all industries who want to guarantee optimum in-
quirements of EN 60079-7 (Electrical apparatus for areas sub- verse-time delayed and temperature-dependent protection of
ject to explosion hazards – Increased safety "e"); their electrical loads (e. g. motors) under normal and heavy
see Chapter 20 "Appendix" --> "Standards and approvals" --> starting conditions (CLASS 5 to CLASS 30), minimize project
"Type overview of approved devices for potentially explosive ar- completion times, inventories and power consumption, and op-
eas (ATEX explosion protection)". timize plant availability and maintenance management.
EC type test certificate for Group II, Category (2) G/D exists. It
Application
has the number PTB 05 ATEX 3022.
The 3RB22/3RB23 solid-state overload relays have been de-
■ Benefits signed for the protection of three-phase asynchronous and sin-
gle-phase AC motors.
The most important features and benefits of the 3RB22/3RB23
solid-state overload relays are listed in the overview table (see If single-phase AC motors are to be protected by the
"Overload Relays" --> "General data"). 3RB22/3RB23 solid-state overload relays, the main current
paths of the current measuring modules must be series-con-
nected (see Technical Information LV 1 T, "Schematics").
Ambient conditions
The devices are insensitive to external influences such as
shocks, corrosive environments, ageing and temperature
fluctuation.
For the temperature range from –25 °C to +60 °C, the
3RB22/3RB23 solid-state overload relays compensate the tem-
perature according to IEC 60947-4-1.

5
Configuration notes for use of the devices below –25 °C or above
+60 °C on request.

■ Accessories
The following accessories are available for the 3RB22/3RB23
solid-state overload relays:
• A sealable cover for the evaluation module
• Box terminal blocks for the current measuring modules size S6
and S10/S12
• Terminal covers for the current measuring modules size S6
and S10/S12
• Push-in lugs for screw fixing the sizes S00 to S3 current mea-
suring modules

Siemens LV 1 · 2009 5/57

 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
3RB22, 3RB23 for high-feature applications

■ Selection and ordering data

3RB22/3RB23 solid-state overload relays for full motor protection with screw terminals or spring-loaded terminals
for stand-alone installation, CLASS 5, 10, 20 and 30 adjustable
Features and technical specifications:
• Overload protection, phase failure protection and unbalance • TEST function and self-monitoring
protection • Internal ground-fault detection with function expansion
• External power supply 24 ... 240 V AC/DC module
• Auxiliary contacts 2 NO + 2 NC • Screw terminals or spring-loaded terminals for auxiliary,
• Manual and automatic RESET control and sensor circuits
• Electrical remote RESET integrated • Input for PTC sensor circuit
• 4 LEDs for operating and status displays • Analog output with function expansion module
Size of Version DT Screw terminals PU PS* PG Weight
contactor (UNIT, per PU
SET, M) approx.
Order No. Price
per PU kg
Evaluation modules
S00 ... S12 Monostable } 3RB22 83-4AA1 1 1 unit 101 0.300
Bistable } 3RB23 83-4AA1 1 1 unit 101 0.300

3RB2. 83-4AA1
5

Size of Version DT Spring-type PU PS* PG Weight

contactor terminals (UNIT, per PU
SET, M) approx.
Order No. Price
per PU kg
Evaluation modules
S00 ... S12 Monostable A 3RB22 83-4AC1 1 1 unit 101 0.300
Bistable A 3RB23 83-4AC1 1 1 unit 101 0.300

3RB2. 83-4AC1

Size of Version DT Order No. Price PU PS* PG Weight

contactor per PU (UNIT, per PU
SET, M) approx.
kg
Function expansion modules
For plugging into evaluation module (1 unit)
S00 ... S12 Analog Basic 1 modules1) } 3RB29 85-2AA0 1 1 unit 101 0.030
Analog output 4 ... 20 mA DC,
with overload warning
Analog Basic 1 GF modules1)2) } 3RB29 85-2AA1 1 1 unit 101 0.030
Analog output 4 ... 20 mA DC,
with internal ground-fault detection and
overload warning
Analog Basic 2 GF modules1)2) } 3RB29 85-2AB1 1 1 unit 101 0.030
Analog output 4 ... 20 mA DC,
with internal ground-fault detection and
ground-fault signaling
Basic 1 GF modules2) } 3RB29 85-2CA1 1 1 unit 101 0.030
with internal ground-fault detection and
overload warning
Basic 2 GF modules2) } 3RB29 85-2CB1 1 1 unit 101 0.030
with internal ground-fault detection and
ground-fault signaling
2)
Note: Analog input modules, e. g. SM 331, must be configured The following information on ground-fault protection refers to sinusoidal
for 4-wire measuring transducers. In this case the analog input residual currents at 50/60 Hz:
module must not supply current to the analog output of the - With a motor current of between 0.3 and 2 times the current setting Ie the
unit will trip at a ground-fault current equal to 30 % of the set current.
3RB22/ 3RB23 relay. - With a motor current of between 2 and 8 times the current setting Ie the
1)
The analog signal 4 ... 20 mA DC can be used for operating rotary coil unit will trip at a ground-fault current equal to 15 % of the set current.
instruments or for feeding into analog inputs of programmable logic - The response delay amounts to between 0.5 and 1 second.
controllers.
* You can order this quantity or a multiple thereof.
5/58 Siemens LV 1 · 2009
 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
3RB22, 3RB23 for high-feature applications
1)
Current measuring modules for direct mounting and stand-alone installation1)2)
Size of Rating Current setting of Short-circuit DT Order No. Price PU PS* PG Weight
contactor3) for induction the inverse-time protection per PU (UNIT, per PU
motor delayed over- with fuse, SET, M) approx.
rated value4) load release type of coor-
dination 2,
gL/gG opera-
tional class5)
kW A kg
Size S00/S02)6)
S00/S0 0.09 … 1.1 0.3 … 3 20 } 3RB29 06-2BG1 1 1 unit 101 0.100
1.1 … 11 2.4 … 25 63 } 3RB29 06-2DG1 1 1 unit 101 0.150

3RB29 06-2.G1
Size S2/S32)6)
S2/S3 5.5 … 45 10 … 100 315 } 3RB29 06-2JG1 1 1 unit 101 0.350

3RB29 06-2JG1

Size S61)6)
S6 with 11 … 90 20 … 200 315 } 3RB29 56-2TH2 1 1 unit 101 1.000

5
busbar
connection
S6 with } 3RB29 56-2TG2 1 1 unit 101 0.600
box termi-
3RB29 56-2TG2 nals
Size S10/S121)
S10/S12 37 … 450 63 … 630 800 } 3RB29 66-2WH2 1 1 unit 101 1.750
and size
14 (3TF68/
3TF69)

3RB29 66-2WH2
3)
Note: Observe maximum rated operational current of the devices.
The connecting cable between the current measuring module 4) Guide value for 4-pole standard motors at 50 Hz 400 V AC. The actual
and the evaluation module is not included in the scope of sup- starting and rated data of the motor to be protected must be considered
ply; please order separately. when selecting the units.
5) Maximum protection by fuse for overload relay, type of coordination 2.
1) The current measuring modules with an Order No. ending with "2" are
designed for direct mounting and stand-alone installation. For For fuse values in conjunction with contactors, see Technical Inforamtion
3TF68/3TF69 contactors, direct mounting is not possible. LV 1 T "Technical specifications" --> "Short-circuit protection with fuses for
2)
motor feeders".
The current measuring modules with an Order No. ending with "1" are 6)
designed for stand-alone installation. The modules with an Order No. with "G" in penultimate position are

■ Accessories
Size of Version DT Order No. Price PU PS* PG Weight
contactor per PU (UNIT, per PU
SET, M) approx.
kg
Connecting cables (essential accessory)
For connection between evaluation module and
current measuring module
S00 ...S3 • Length 0.1 m } 3RB29 87-2B 1 1 unit 101 0.010
(only for mounting of the evaluation module
directly onto the current measuring module)
S00 ... S12 • Length 0.5 m } 3RB29 87-2D 1 1 unit 101 0.020
3RB29 87-2.
For more accessories, see page 5/60.

* You can order this quantity or a multiple thereof.

Siemens LV 1 · 2009 5/59
 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
Accessories

■ Overview
Overload relays for standard applications Overload relays for high-feature applications
The following optional accessories are available for the The following optional accessories are available for the
3RB20/3RB21 solid-state overload relays: 3RB22/3RB23 solid-state overload relays:
• One terminal bracket each for the overload relays size S00 • A sealable cover for the evaluation module
and S0 (sizes S2 to S12 can be installed as stand-alone instal- • Box terminal blocks for the current measuring modules size S6
lation without a terminal bracket) and S10/S12
• One mechanical remote RESET module for all sizes • Terminal covers for the current measuring modules size S6
• One cable release for resetting devices which are difficult to and S10/S12
access (for all sizes) • Push-in lugs for screw fixing the sizes S00 to S3 current mea-
• One sealable cover for all sizes suring modules
• Box terminal blocks for sizes S6 and S10/S12
• Terminal covers for sizes S2 to S10/S12

■ Selection and ordering data

Version Size DT Order No. Price PU PS* PG Weight
(UNIT, per PU
SET, M) approx.
kg
Terminal brackets for stand-alone installation1)
For separate mounting of the overload S00 } 3RB29 13-0AA1 1 1 unit 101 0.060
relays; screw and snap-on mounting onto S0 } 3RB29 23-0AA1 1 1 unit 101 0.080
TH 35 standard mounting rail
5

3RB29 .3-0AA1
Mechanical RESET2)
Resetting plungers, holders and formers S00 ... } 3RU19 00-1A 1 1 unit 101 0.038
S10/S12
Pushbuttons with extended stroke B 3SB30 00-0EA11 1 1 unit 102 0.020
(12 mm), IP65, Ø 22 mm
Extension plungers A 3SX1 335 1 1 unit 102 0.004
For compensation of the distance between
a pushbutton and the unlatching button of
3RU19 00-1A the relay
with pushbutton and
extension plunger
Cable releases with holder for RESET2)
For Ø 6.5 mm holes S00 ...
in the control panel; S10/S12
max. control panel thickness 8 mm
• Length 400 mm } 3RU19 00-1B 1 1 unit 101 0.063
• Length 600 mm } 3RU19 00-1C 1 1 unit 101 0.073

3RU19 00-1.
1) Only for 3RB20/3RB21.
2) Only for 3RB20/3RB21. The accessories are identical to those of the
3RU11 thermal overload relays.

* You can order this quantity or a multiple thereof.

5/60 Siemens LV 1 · 2009
 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
Accessories

Version Size DT Order No. Price PU PS* PG Weight

(UNIT, per PU
SET, M) approx.
kg
Sealable covers
For covering the setting knobs
• For 3RB20/3RB21 S00 ... } 3RB29 84-0 1 10 units 101 0.020
S10/S12

• For 3RB22/3RB23 -- } 3RB29 84-2 1 10 units 101 0.050

Terminal covers
Covers for cable lugs and busbar
connections
• Length 55 mm1) S3 } 3RT19 46-4EA1 1 1 unit 101 0.040
• Length 100 mm S6 } 3RT19 56-4EA1 1 1 unit 101 0.070
• Length 120 mm S10/S12 } 3RT19 66-4EA1 1 1 unit 101 0.130
3RT19 46-4EA1 Covers for box terminals
• Length 20.6 mm1) S2 } 3RT19 36-4EA2 1 1 unit 101 0.020
• Length 20.8 mm1) S3 } 3RT19 46-4EA2 1 1 unit 101 0.025
• Length 25 mm S6 } 3RT19 56-4EA2 1 1 unit 101 0.030
}

5
• Length 30 mm S10/S12 3RT19 66-4EA2 1 1 unit 101 0.040
3RT19 36-4EA2 Covers for screw terminals S6 } 3RT19 56-4EA3 1 1 unit 101 0.020
The figures show mount- Between contactor and overload relay, S10/S12 } 3RT19 66-4EA3 1 1 unit 101 0.060
ing on the contactor without box terminals
(1 unit required per combination)
Box terminal blocks
For round and ribbon cables
• Up to 70 mm2 S62) } 3RT19 55-4G 1 1 unit 101 0.230
• Up to 120 mm2 S6 } 3RT19 56-4G 1 1 unit 101 0.260
• Up to 240 mm2 S10/S12 } 3RT19 66-4G 1 1 unit 101 0.676
For conductor cross-sections
see Technical Information LV 1 T,
"Technical specifications".

3RT19 5.-4G
Push-in lugs
For screw fixing of 3RB22/3RB23 -- } 3RP19 03 1 10 units 101 0.002
overload relays

3RP19 03
For screw fixing of 3RB29 06 current S00 ...S3 A 3RB19 00-0B 100 10 units 101 0.100
measuring modules
(2 units are required per module)

3RB19 00-0B
Tools for opening spring-loaded terminals by hand
Screwdrivers, Can be C 8WH9 200-0AA00 1 10 units 044 0.032
2.5 mm x 0.4 mm, used for
length approx. 160 mm; green, auxiliary cir-
suitable for a max. conductor cross- cuit connec-
section of 1.5 mm2 tions
1)
Only for 3RB20/3RB21. The accessories are identical to those of the
3RU11 thermal overload relays.
2)
In the scope of supply for 3RT10 54-1 contactors (55 kW).

* You can order this quantity or a multiple thereof.

Siemens LV 1 · 2009 5/61
 © Siemens AG 2009

Overload Relays
3RB2 Solid-State Overload Relays
Accessories

Version Size/ Use DT Order No. Price PU PS* PG Weight

Color per PU (UNIT, per PU
SET, M) approx.
kg
Tools for opening Cage Clamp terminals
Screwdrivers
3.5 mm x 0.5 mm, Length approx. Main and C 8WA2 880 1 1 unit 041 0.034
suitable for a max. 175 mm; auxiliary cir-
conductor cross-sec- green, partially cuit connec-
8WA2 803 tion of 2.5 mm2 insulated tions
Length approx. C 8WA2 803 1 1 unit 041 0.024
175 mm;
green
Blank labels
Unit labeling plates 10 mm x 7 mm, 3RB2, D 3RT19 00-1SB10 100 816 units 101 24.000
For SIRIUS devices pastel turquoise 3RU11
20 mm x 7 mm, C 3RT19 00-1SB20 100 340 units 101 0.200
pastel turquoise
Inscription labels for 19 mm x 6 mm, 3RB2, D 3RT19 00-1SB60 100 3060 units 101 15.000
sticking pastel turquoise 3RU11
For SIRIUS devices 19 mm x 6 mm C 3RT19 00-1SD60 100 3060 units 101 12.000
3RT19 00-1SB10 zinc yellow
Computer labeling systems
For individual inscription of unit labeling
plates
Obtainable from:
murrplastik Systemtechnik GmbH
http://www.murrplastik.com
5

* You can order this quantity or a multiple thereof.

5/62 Siemens LV 1 · 2009