Siemens 3RB12 User manual

Elektronisches Überlastrelais 3RB12
Solid-state overload relay
Relais de surcharge electronique
Relé electronico di sobrecarga
Relè elettronico di sovraccarica
Elektroniska överlastrelä
Betriebsanleitung
Instructions
Bestell-Nr./Order No.: 3ZX1012-0RB12-1AA1
Ausgabe/Edition 01/2003
GWA 4NEB 631 2282-30a

3RB1246-1P
3RB1246-1Q
3RB1246-1E
a10 15
b34 29
c29 24
d46 47
e48 ---
f 4 - - -
100
70
50
∅ 4,5
7, 2
Ic
85
127,5
5
100
Ib
Ia
b
e
a
fc
d
x
y
3ZX1012-0RB12-1AA1

3RB1253-
0F
3RB1257-
0K
3RB1262-
0L
a 120 145 230
b858585
c155 175 190
d 110 105 120
e405070
f∅ 7∅ 9∅ 11
g425270
h3748---
i 125 130 135
j414655
k203040
l 131 151 166
m 7,2 7,2 7,2
n 13 - - - - - -
o 145 160 175
idb
a
g
e
h
km
f
o
IIb
IIa
l
j
n
c
3ZX1012-0RB12-1AA1

III
M
1~
NSB00302a
L1 L2 L3
T1 T2 T3
L
N
3RB12
3ZX1012-0RB12-1AA1

H2
F2 F3 F4
A1
A2
K1E
135
642
135
L1 L2 L3
A2 A1
F5
F1
T1 T2 T3
642
U W V
CLASS
97
S1A
95
9896
K1E
S1E
Test/
Reset
K1 Overload
K2 Ground
Fault
Y1Y2
Z1
Z2
5, 10, 15, 20, 25, 30
Ground
Fault
H1 H3
05 07
06 08
Ready
Ground
Fault
Overload
C2
T2/
C1
Y1Y2
Automatic-
Reset
Remote-
Reset
ϑ
Y1
Y2
T1
ϑ
T2/
C1
3UL22
3 RB 12
⇑
⇑
K1E
L1
L2
L3
N
M
3 ~
IV
3RB12
3ZX1012-0RB12-1AA1

V3RB12..-...0
3RB12..-...2
25
30
40
50
60 70 80 90
100
5
10
15
20 25
30
Class
Test/
Reset
G/9401 3RB1246-1EM00
95 96 97 98 08070605
A1 Y1 Y2
A2 T1 T2/C1 C2
Overload
Gnd Fault
Ready
Reset
Gnd Fault
AC 220-240V J- -
3RB12
NC Overload NO NC Gnd Fault NO
A
AB
3ZX1012-0RB12-1AA1

25
30
40
50
60 70 80 90
100
5
10
15
20 25
30
Class
Test/
Reset
G/9401 3RB1246-1EM00
95 96 97 98 08070605
A1 Y1 Y2
A2 T1 T2/C1 C2
Overload
Gnd Fault
Ready
Reset
Gnd Fault
AC 220-240V ϑ↑ ↑
3RB12
NC NO NC NO
A
AB
Tripped
OVL-Warning
3RB12..-...1
3RB12..-...3
VI
3ZX1012-0RB12-1AA1

VIII
VII
x Ie
tA
1 2 5
10 20 50
12 580,7
1 2 5
10 20 50
100 120
s min
15 10
5
CLASS
CLASS 30
25 20
x Ie
1 2 5
10 20 50
12 580,7
1 2 5
10 20 50
100 120
s min
15 10
5
CLASS
tA
CLASS 30
25 20
3ZX1012-0RB12-1AA1

Device description
3ZX1012-0RB12-1AA1 11
English
Limited touch protection
Degree of protection in conformity with IEC 60529:
IP 20 for devices 70 mm
IP 00 for devices > 70 mm
Shock-proof in conformity with DIN VDE 0106, Part
100.
Installation and maintenance by technical personnel
only. Follow the operating instruction!
1 Device description
The 3RB12 electronic overload relay protects electrical
equipment, such as three-phase AC motors and trans-
formers, with three different protection mechanisms.
Overload
protection The 3RB12 compares the motor current actually
flowing with the set current and evaluates the values
in a microprocessor.
Thermistor
protection PTC thermistors in the motor windings sense the motor
temperature. If the thermistor responds, the relay trips.
Earth-fault
protection Versions with internal earth-fault detection are suitable
for service in three-wire systems.
Versions with earth-fault detection by means of an
external summation current transformer are suitable
for service in three-wire and four-wire systems.
WARNING
HAZARDOUS VOLTAGE
CAN CAUSE ELECTRICAL SHOCK
AND BURNS.
DISCONNECT POWER BEFORE PROCEEDING
WITH ANY WORK ON THIS EQUIPMENT.

Installation
12 3ZX1012-0RB12-1AA1
English
2Installation
For dimension drawings, see graphics section, Fig. I
and II.
Mounting position: any
Mounting of 70 mm devices:
■ Snap-on mounting on 35 mm mounting rail in con-
formity with EN 50 022 or
■ srew mounting by means of inserted lugs as
accessory (3RB1900-0B).
Mounting of the 120 mm, 145 mm und 230 mm
devices:
■ Crew mounting integrated in the casing.
■ In addition for 120 mm size:
Baseplate for snap-on fastening on 75 mm mount-
ing rail (3UF1900-0J) available as accessory.
3 Connection
3.1 Main conductor connection
3.1.1 Current range up to 100 A
■ Rated motor currents from 1.25 A to 100 A:
Insert the motor leads per phase through the open-
ings (x) in the unit (see graphics section, Fig. Ia).
■ Rated motor currents less than 1.25 A:
Insert the motor leads per phase through the open-
ings (x), take them back through the loop opening (y)
and insert them again through the openings (x). You
will produce two loops in this way (see graphics sec-
tion, Fig. Ia).
The following table lists the number of loops for the
various rated motor currents.

Connection
3ZX1012-0RB12-1AA1 13
English
The device setting current Iecalculated according to:
Ie= n x IN
Example IN= 0.5 A; n = 3; Ie= 1.5 A
Protection of
single-phase
motors
If single-phase AC motors are to be protected by the
3RB12 solid-state overload relay, phase L must be
looped through the device.
The main circuits must be connected as shown in
Fig. III.
Note
This is only possible if the device has no internal earth
fault detection:
3RB12 46- ...0., -...1.
3RB12 53- ...0., -...1.
3RB12 57- ...0., -...1.
3RB12 62- ...0., -...1.
Number of loops n 5 4 3 2
Rated motor current IN [A] 0.25 to
0.3
0.31 to
0.41
0.42 to
0.62
0.63 to
1.24

Connection
14 3ZX1012-0RB12-1AA1
English
3.1.2 Current range 50 A to 820 A
Busbar connection: see graphics section, Fig. II
3.2 Auxiliary conductor connection
Thermistor
sensor A link (A) is in place when the device is delivered. This
link must be removed when the sensor is connected
(see illustration in Fig. V and VI).
3.3 Connection scheme
See graphics section of Fig. IV for circuit diagram,
showing Automatic resets and remote resets.
Facility for connecting summation current transformer
3UL22 for external earth fault monitoring.
Finely stranded
conductor with
cable lug
[mm2]
Stranded con-
ductor with
cable lug
[mm2]
Connection
screws Tightening torque
[Nm/lb.in]
Tag
termination
[mm x mm]
3RB1253 35 to 95 50 to 120 M8 10 to 14 /
89 to 24
20 x 4
3RB1257 50 to 240 70 to 240 M10 14 to 24 /
124 to 210
30 x 6
3RB1262 50 to 240 185 to 240 M 10
(Connec-
tion to con-
tactor
3TF68)
14 to 24 /
124 to 210
40 x 8
M 12 (Con-
nection to
contactor
3TF69)
20 to 35 /
177 to 310
Solid
[mm2]
Finely stranded with/
without end sleeve
[mm2]
AWG Connecting screws
[mm]
Tightening torque
[Nm/lb.in]
1x(0.5 to 4)
2x(0.5 to 2.5)
1x(0.5 to 2.5)
2x(0.5 to 1.5)
20 to 14 0.8x4...5.5
Pozidriv 2
0.8 to 1.2/
7 to 11

Operation
3ZX1012-0RB12-1AA1 15
English
4Operation
4.1 Setting the current
■ Use the current setting range knob to set the
appropriate current.
4.2 Adjust tripping classes
Note
The motor, leads and contactor must be rated for the
appropriate class. Class 10 as delivered.
■ Check the class setting before initial start-up and
correct it if necessary!
■ Use the class changeover switch to select the appro-
priate tripping characteristic (see graphic section of
Fig. VII).
In the event of unsymmetry > 40 % (as per NEMA) and
phase failure, tripping occurs as shown in Fig. VIII. The
characteristics apply to a cold start. For starting under full
load, the tripping times tAare reduced.
Note
With the aid of the sealable cover plate 3RB1900-0A,
the current range setting knob and the class changeover
switch can be protected from tampering. To do this,
simply snap on the cover plate instead of the middle
nameplate.

Operation
16 3ZX1012-0RB12-1AA1
English
4.3 Device statuses
Five minutes after overload tripping, the 3RB12 can be
reset to operating mode.
Type 3RB12..-..... 3RB12..-...0.
3RB12..-...2. 3RB12..-...1. 3RB12..-...3.
Status Operating indic. Auxiliary switch
Device ready for
operation
no overload
not tripped
Ready LED:
Green steady
light
95/96, 05/06 closed
97/98, 07/08 open
Changed auxiliary switch statuses
Overload alarm Overload LED:
Red flashing
light*
05/06 open
07/08 closed
Overload trip/
thermistor trip
Overload LED:
Red steady light
95/96 open
97/98 closed
Earth fault alarm Gnd. Fault LED:
Red steady light
05/06 open
07/08 closed
95/96 open
97/98 closed
* The overload LED flashes when the limit tripping current is reached and
indicates that tripping is imminent.
Status Mode indicator Auxiliary switch
Device not ready
for operation
control voltage
failure
Ready LED:
Dark
Monostable version of device:
95/96, 05/06 open
97/98, 07/08 closed
Bistable version of device:
Switching statuses are retained

Operation
3ZX1012-0RB12-1AA1 17
English
4.4 Test
Statuses after the Test/Reset button has been pressed:
Test Status Without
main current
With
main current*
button O.k. Faulty O.k. Faulty
Press for
up to 2 s
LED Ready
LED Gen. Fault
LED Overload
Status of auxiliary
switching elements unchanged
Press for
after 2 s
LED Ready
LED Gen. Fault
LED Overload
Status of auxiliary
switching elements
un-
changed
Reset** un-
changed
Reset**
Press for
> 5 s
LED Ready
LED Gen. Fault
LED Overload
Status of auxiliary
switching elements Reset
LED lights up LED flashes LED flickers LED dark
*Unless current is detected in all three phases, the device behaves as listed in the
"Without main circuit current“ column.
**Status of auxiliary switching elements "Reset":
95/96, 05/06 open, 97/98, 07/08 closed.

Operation
18 3ZX1012-0RB12-1AA1
English
Note
The test with a test time of less than 5 s can be per-
formed during operation. In a fault-free state the outputs
remain unchanged.
4.5 Reset
Reset
function with
free trip
The protection functions are not impeded by holding
down the test/reset button.
When the
3RB12 has
tripped because
of
Reset the overload relay after the following times by
briefly pressing
the test / reset
button
Remote reset
(briefly press but-
ton at Y1-Y2)
automatic-reset
(bridge** Y1-Y2)
Test immediately
Overload*after 5 min
Thermistor*If the temperature has reached 5 K below the response
temperature
Earth fault immediately not effective
*If thermistor- and overload has tripped simultaneously, the longer reset
phase applies.
** Bridge (B) is fixed to Y1 as delivered (see graphics section of Fig. V and VI).

Technical data
3ZX1012-0RB12-1AA1 19
English
5 Technical data
Specifications DIN VDE 0660 Part 102 / IEC 60947-4-1,
DIN VDE 0660 Part 200 / IEC 60947-5-1,
UL 508, CSA C 22.2
EMC Pulse packets (burst), IEC 61000-4-4 2 kV
Discharge of static electricity, IEC 61000-4-2 8 kV
Radiated high-frequency fields, IEC 61000-4-3 3 V/m
Surge voltage, IEC 61000-4-5 2 kV
Weight 70 mm: 0.6 kg 145 mm: 1.9 kg
120 mm: 1.0 kg 230 mm: 3.2 kg
Rated control
supply
voltage
Working range:
AC 0.85 to 1.1 x Us; 2 VA
24 V DC: 0.85 to 1.2 x Us (DIN 19 240); 2W
Main circuit Frequency 50/60 Hz
Rated insulation voltage Ui1000 V
3RB1246 690 V
Permissible ambient temperature -25 to +70 °C
Storage: -40 to +80 °C
Tripping limit values with three-pole
symmetrical overload:
Tripping current 110...120% x Ie
Tripping time < 20 min
Auxiliary
circuit Contacts 2 x (1 NO and 1 NC)
Electrical isolation of the auxiliary switch (potential-free)
IEC: Rated insulation voltage Ui300 V
Switching capacity:
AC-15: 6A/24V; 6A/120V; 3A/230V
DC-13: 2A/24V; 0.55A/60V; 0.25A/125V
UL/CSA: B300, R300

Technical data
20 3ZX1012-0RB12-1AA1
English
Short-circuit
protection Main circuit
Short-circuit protection with fuses for motor feeders with
short-circuit currents up to 50 kA at 690 V, 50/60 Hz (see
data given in catalog)
Control circuit
Fuse links, duty class gL/gG 6 A
quick-acting 10 A
Protective circuit-breaker 1.6 A
C characteristic
Thermistor
protection Thermistor sensor in the motor is connected to terminals
T1/T2
Total cold resistance Rcold 1.5 kΩ
Measuring circuit loading ≤5 mW
(at Rcold = 1.5 kΩ)
Voltage at sensor circuit ≤2 V (at Rcold = 1.5 kΩ)
Response value 2.7 to 3.1 kΩ
Return value 1.5 to 1.65 kΩ
Earth fault
protection The following information based on sinusoidal fault
currents of 50/60 Hz:
external
Summation current transformers 3UL220.-.A are con-
nected to terminal C1/C2. The pick-up delay is 200 ms ≤
t ≤ 500 ms.
internal
With a motor current between 0.3 and 2 times the set
current, the device trips in the event of an earth-fault cur-
rent of 30% of the set current.
With a motor current between 2 and 8 times the set cur-
rent, the device trips in the event of an earth-fault current
of 15% of the set current.
The pick-up delay is 0.5 to 1 seconds.

Description de l'appareil
3ZX1012-0RB12-1AA1 21
Français
Protection partielle contre les contacts directs
Degré de protection selon CEI 60529:
IP 20 pour relais de largeur 70 mm
IP 00 pour relais de largeur > 70 mm
Protégé contre l'accès avec un doigt selon
DIN VDE 0106, partie 100
Mise en service et maintenance uniquement par des per-
sonnes qualifiées. Respectez les instructions de service!
1 Description de l'appareil
Le relais électronique de surcharge 3RB12 dispose de
différents mécanismes de protection pour les matériels
électriques tels que moteurs triphasés et transforma-
teurs.
Protection
contre les
surcharges
Le 3RB12 compare le courant momentané du moteur
avec le courant de réglage du relais et traite les valeurs
dans un microprocesseur.
Protection de
moteurs par
thermistance
Les sondes à thermistance CTP placées dans les en-
roulements du moteur assurent la mesure de la tempé-
rature de ce dernier. Lors du dépassement d'un seuil, le
relais provoque le déclenchement.
Protection
contre les
défauts
à la terre
Appareils avec reconnaissance interne de défauts à la
terre pour réseaux 3 conducteurs.
Appareils avec reconnaissance de défauts à la terre par
transformateur sommateur externe pour réseaux á 3 ou
4 conducteurs.
Attention !
Tension dangereuse !
Risque d’électrocution et de brûlure.
Isoler cet appareil du réseau avant d’y
intervenir pour travaux.