Contactors and Contactor Assemblies

3TF, 3TG, 3TB, 3TD, 3TE, 3TK, 3TC contactors

Contac tors and Contactor Assemblies

Technical data
General technical data Page Further specific technical data Page

Permissible mounting position, mounting instructions 3/179 3TG10 3/183

Ratings of the auxiliary contacts 3/180 3TF68 and 3TF69 3/185

Positively driven contacts 3/180 3TB50 to 3TB56 3/189

Endurance of the auxiliary contacts 3/181 3TD68 contactor assemblies 3/192

Endurance of the main contacts 3/181 3TE68 contactor assemblies 3/193

3TK1 3/194

3TC44 to 3TC56 3/196

3TC74 and 3TC78 3/198

Contactor type Permissible mounting position

Permissible mounting position, mounting instructions
3TG10 Any

The contactors are designed for operation on a vertical mounting surface.

For designs for upright mounting, see below.
22,5° 22,5° 22,5° 22,5° 22,5° 22,5°
NSB00649

90° 90°

NSB00650a
3TF6 3TF68 and 3TF69 (AC operation) 1)2) Not suitable
3TF68 and 3TF69 (DC economy circuit) 1)2)

3TB5 Not suitable 3TB50 to 3TB56 3)

3TK1 3TK1 4) Not suitable

3TC Not suitable 3TC4, 3TC5, 3TC7

3TD 3TD68 (AC operation) 1)2) Not suitable

3TE 3TE68 (AC operation) 1)2) Not suitable

Mounting instructions Upright mounting

1) A minimum clearance of 30 mm is recommended between the contactors The following contactors can also be supplied for use in the upright position.
in order to simplify the replacement of the laterally mounted auxiliary swit- In this case the Order No. must be supplemented with "-Z" and the order
ches. code "B01".
2) If the contactors are mounted at a 90° angle (conducting paths horizon- Type Additional charge
tally one above the other), the following reductions apply: 3TC44
Operating frequency: 3TF68 and 3TF69 – to 80% of the standard values 3TC48
3TC52
3) No deviations from the vertical axis are allowed for reversing operation wit- 3TC56
hout a mechanical interlock.
3TF68 and 3TF69
4) 3TK1: upright mounting also permissible.

Siemens NS K · 2002 3/179

 Contactors and Contactor Assemblies

3TF, 3TG, 3TK, 3TC, 3TB contactors

Technical data

Contactor Type 3TG10 3TF68 3TK1 3TC4 3TC5 3TB50 3TB52

and and ...
3TF69 3TC7 3TB56
Ratings of the auxiliary contacts
Rated insulation voltage Ui acc. to IEC 60 947-5-1/DIN VDE 0660 acc. to IEC 60 158-1
(pollution degree 3) Part 200
V 400 690

Conventional thermal current Ith = Ie/AC-1 Ie/AC-1

rated operational current Ie/AC-12 A 20 1)2) 10 10 10 10 10 10

Load ratings with AC

Rated operational current Ie/AC-15/AC-14 Ie/AC-11 Ie/AC-11
at rated operational voltage Ue 24 V A 4 10 6 10 10 10 10
110 V A 4 10 6 10 10 10 10
125 V A 4 10 6 10 10 10 10
220 V A 4 6 6 6 6 6 6
230 V A 4 5.6 6 5.6 5.6 5.6 5.6
380 V A 3 4 4 4 4 4 4
400 V A 3 3.6 4 3.6 3.6 3.6 3.6
500 V A – 2.5 1 2.5 2.5 2.5 2.5
660 V A – 2.5 1 2.5 2.5 2.5 2.5
690 V A – 2.3 1 – – – –

Load ratings with DC

Rated operational current Ie/DC-12 Ie/DC-1 Ie/DC-1
at rated operational voltage Ue 24 V A 16 10 – 10 10 10 10
48 V A 8 10 – 10 10 10 10
110 V A 2 3.2 – 3.2 8 3.2 8
125 V A 1.7 2.5 – 2.5 6 2.5 6
220 V A 1 0.9 – 0.9 2 0.9 2
440 V A – 0.33 – 0.33 0.6 0.33 0.6
600 V A – 0.22 – 0.22 0.4 0.22 0.4

Rated operational current Ie/DC-13 Ie/DC-11 Ie/DC-11

at rated operational voltage Ue 24 V A 3 10 6 10 10 10 (10) 3) 10 (10) 3)
48 V A 1.2 5 6 5 5 5 ( 7) 5 ( 4)
110 V A 0.5 1.14 1.8 1.14 2.4 1.14 ( 3.2) 2.4 ( 1.8)
125 V A 0.4 0.98 – 0.98 2.1 0.98 ( 2.5) 2.1 ( 1.6)
220 V A 0.27 0.48 0.6 0.48 1.1 0.48 ( 0.9) 1.1 ( 0.9)
440 V A – 0.13 – 0.13 0.32 0.13 ( 0.33) 0.32 ( 0.27)
600 V A – 0.07 – 0.07 0.21 0.075 ( 0.22) 0.21 ( 0.18)

Contactor Type 3TG10..-0... 3TF68 and 3TF69 3TB50 ... 3TB56 3TK1
3TC44 ... 3TC56
s, u and U ratings of the auxiliary contacts
Rated voltage max. AC V 600 600 600 600
Auxiliary switch
blocks:300

Making and breaking capacity A 600, Q 300 A 600, P 600 A 600, P 600 A 600, P 600
Conventional
thermal current:
10 A at AC 240 V

Contactor Type 3TF68 and 3TF69 4) 3TC44 ... 3TC56 4) 3TB50 ... 3TB56
Positively driven operation between welded main contacts and
auxiliary NC contacts:
Positively driven contacts of
3TF, 3TC, 3TB contactors
The contacts are positively driven if they are linked together mechanically in such a way that the NO and NC contacts cannot be closed at the same
time (positively driven operation between welded main contacts and auxiliary NC contacts).

Basic unit
Basic unit and mounted
auxiliary switches
Basic unit and laterally mounted x x x
auxiliary switches

1) With tab connectors 16 A. 3) The values in brackets apply to auxiliary con- be connected in series.
2) If the three main conducting paths are loaded tacts with a late-opening NC contact.
with 20 A and I > 10 A, the permissible ambient 4) In the case of the 3TF68 and 3TF69 as well as
temperature for the fourth conducting paths the 3TC44, one NC contact belonging to each
40 °C. of the left and right auxiliary switch blocks must

3/180 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TF, 3TB contactors

Technical data

Endurance of the auxiliary contacts

The contact endurance for the 3TF68 and 3TF69 contactors
AC-12 and AC-15/AC-14 utiliza- with AC 230 V
tion categories is mainly de-
4 NSB00651b
pendent on the breaking cur- 3
rent. It is assumed that the op-
2
erating mechanisms are
switched randomly, i. e. not
107
synchronized with the phase 8
angle of the supply system. 6
4
3
2

6
10
8
6
4
3
2
5
10
10 -2 2 3 4 6 8 10-1 2 3 4 6 8 10 0 2 3 4 6 8 10 1 2
Ia ( A )

Endurance of the main contacts

The characteristic curves show 3TB50 to 3TB56 contactors
the contact endurance of the
Contactor type 3TB50 3TB54
contactors when used to switch 3TB52 3TB56
resistive and inductive three- 10 7
8 NSB00652a
phase loads (AC-1/AC-3), de- 6
pending on the breaking cur- 4
Operating cycles at 400 V

rent and the rated operational

2
voltage. It is assumed that the
operating mechanisms are 10 6
8
switched randomly, i.e. not syn- 6
chronized with the phase angle 4
of the supply system.
2
The rated operational current Ie
for the AC-4 utilization category 10 5
8
(breaking six times the rated 6
operational current) is designed 4
for a contact endurance of ap-
proximately 200 000 operating 2
cycles. 104
8
If a shorter endurance is suffi- 6
cient, the rated operational cur- 4
rent Ie/AC-4 can be increased.
2
For mixed operation, i.e. normal
switching (breaking the rated 103
operational current according to 10 30 40 50 60 80 100 200 300 400 600 800 1000 2000 Ia (A) 4000
the AC-3 utilization category) in 110 170 250 400 Ie (A)
combination with intermittent 55 90 132 200 PN (kW)
inching (breaking several times
the rated operational current ac-
cording to the AC-4 utilization ca-
tegory), the contact endurance Where: Legend:
can be calculated approximately X Contact endurance for mixed opera- PN = Ratings of
from the following equation: tion in operating cycles three-phase motors with
A Contact endurance for squirrel-cage rotor at 400 V
A
X = ---------------------------------------------------------- normal operation (Ia = Ie) in Ia = Breaking current
C A
1 + --------- -  ---- – 1 operating cycles Ie = Rated operational current
100 B B Contact endurance for inching
(Ia = multiple of Ie) in
operating cycles
C Inching operations as a percentage of
total switching operations

Siemens NS K · 2002 3/181

 Contactors and Contactor Assemblies

3TF and 3TC contactors

Technical data

Contact erosion indication for 3TF68 and 3TF69 vacuum contactors

The contact erosion of the vac- The vacuum interrupter must be position. It is advisable to re-
uum interrupters can be moni- replaced if the distance indi- place all three interrupters in or-
tored in the closed position by cated by one of the double der to ensure maximum
means of three white double slides is less than 0.5 mm while reliability.
slides on the contactor base. the contactor is in the closed

Endurance of the main contacts

3TF68 and 3TF69 contactors
Contactor type 3TF68 3TF69
10 7
10 7 8 6 8 NSB00654a
8 6
4 6
6 4 4
4 2
Operating cycles at 400 V
Operating cycles at 230 V

Operating cycles at 690 V

Operating cycles at 500 V

2 2
6
2 6 10
10 8 6
10
10 6 8 6 8
8 6
4 6
6 4
4
4
2
2 2
2 5
10
10 5 8 5
5 8 10
10 6 8
8 6
4 6
6 4
4
4 2
2
2
2 4
4 10
10 8 4
8 10
10 4 6 8
8 6 6
4
6 4
4
4
2
2
2
2 10
3
10 3 3
10
100 200 400 600 1000 2000 4000 II a (A) 6000
635
820 I e (A)
335 PN (kW)
450

3TC44 to 3TC56 contactors 3TC74 and 3TC78 contactors

107 20 NSB00656
8 NSB00655
6
18
Operating cycles at 500 V

4
Operating cycles at 500 V

3TC44 3TC48 3TC52 3TC56

2
16
10 6
8
6 14
4
12
2

105 10
8
6
4 8

2
6
104
8 4
6
4
2
2
0,5
103 50 100 150 200 250 300 Ia (A) 400
10 20 40 100 200 400 600 1000 2000 Ia (A) 4000

Legend:
PN = Ratings of
three-phase motors with
squirrel-cage rotor at 400 V
Ia = Breaking current
Ie = Rated operational current

3/182 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TG10 contactors

Technical data

3TG10
General data
Mechanical endurance operating 3 million
cycles
Electrical endurance at Ie operating AC-1 0.1 million
cycles AC-3 0.4 million
Rated insulation voltage Ui (pollution degree 3) V 400
Rated impulse withstand voltage Uimp kV 4
Safe isolation acc. to DIN VDE 0106 Part 101 and A1 (draft 2/89) V up to 300
between coil and contacts
Permissible ambient temperature in operation 1) °C –25 ... +55
when stored °C –50 ... +80
Degree of protection acc. to IEC 60 947-1 and IEC 60 529 (VDE 0470 Part 1) IP 00, coil system IP 20
Shock resistance
Rectangular pulse AC and DC operation g/ms 5.1/5 and 3.5/10
Sine pulse AC and DC operation g/ms 7.9/5 and 5.2/10
Short-circuit protection
Fuse links
Utilization category gL/gG NH Type 3NA
DIAZED Type 5SB
NEOZED Type 5SE
acc. to IEC 60 947-4/DIN VDE 0660 Part 102 Type of coord. "1" 2) A 25
Type of coord. "2" 2) A 10
Miniature circuit-breaker C-characteristic A 10
Control circuit
Coil voltage tolerance 0.85 ... 1.1 × Us

Power consumption of the coils (with coil in cold state and 1.0 × Us)
AC operation VA 4.4
p.f. 0.9 (hum-free)
DC operation W 4

Operating times (break-time = opening time + arcing time) AC operation DC operation

Closing closing time NO ms 10 ... 50 11 ... 50
opening time NC ms 5 ... 45 5 ... 45
Opening opening time NO ms 20 ... 30 19 ... 35
closing time NC ms 20 ... 30 21 ... 39
Arcing time ms 10 ... 15
Main circuit
Load ratings with AC
AC-1 utilization category, switching resistive load
Rated operational current Ie at 55 °C up to 400 V 1)
with screw connection A 20
with tab connector A 16
Ratings Ue of three-phase loads p.f. = 1 V 400 230/220
with screw connection kW 13 7.5
with tab connector kW 10 6.0
Minimum conductor cross-section with Ie load mm2 2.5
AC-2 and AC-3 utilization categories
Rated operational currents Ie up to 400 V A 8.4
Ratings of slipring or squirrel-cage motors kW 4
at 50 Hz and 60 Hz and at 400 V
AC-5a utilization category (permissible supply impedance: ≥ 0.5 Ω)
Switching gas discharge lamps
per main conducting path at 50 Hz 230 V Uncorrected Lead-lag
Rating per lamp W 18 36 58 18 36 58
Rated operational current per lamp A 0.37 0.43 0.67 2 × 0.11 2 × 0.21 2 × 0.32
Number of lamps units 43 37 24 2 × 81 2 × 42 2 × 28

1) If the three main conducting paths are loaded 2) According to excerpt from IEC 60 947-4-4 Type of coordination "2":
with 20 A and I > 10 A, the permissible ambient (VDE 0660 Part 102): No damage can be tolerated to the overload
temperature for the 4th conducting paths is Type of coordination "1": relay, but contact welding on the contactor is
40 °C. Destruction of the contactor and the overload permitted if the contacts can be easily sepa-
relay is permissible. The contactor and/or over- rated.
load relay must be replaced if necessary.

Siemens NS K · 2002 3/183

 Contactors and Contactor Assemblies

3TG10 contactors

Technical data

3TG10
Main circuit
Load ratings with AC
Switching gas discharge lamps with correction, electronic ballast Parallel correction El. ballast, 1 lamp El. ballast, 2 lamp
per main conducting path at 50 Hz 230 V
Rating per lamp W 18 36 58 18 36 58 18 36 58
Capacitor µF 4.5 4.5 7 6.8 6.8 10 10 10 22
Rated operational current per lamp A 0.11 0.21 0.32 0.10 0.18 0.27 0.18 0.35 0.52
Number of lamps units 15 15 10 39 39 26 2 x26 2 × 26 2 x1
AC-5b utilization category, switching incandescent lamps kW 1.6
per main conducting path at 50 Hz 230 V
Load ratings with DC
L
DC-1 utilization category, switching resistive load ( ---- ≤ 1 ms)
R
Rated operational currents Ie
Conducting paths connected in series 1 2 3 4
up to 24 V A 16 16 18 20
60 V A 6 16 18 20
110 V A 2 6 16 20
220 V/240 V A 0.8 1.6 6 20
L
DC-3 and DC-5 utilization categories, ( ---- ≤ 15 ms)
shunt and series motors R

Rated operational currents Ie

Conducting paths connected in series 1 2 3 4
up to 24 V A 10 16 16 18
60 V A 0.5 5 16 16
110 V A 0.15 0.35 10 10
220 V/240 V A – – 1.75 2
Operating frequency
Operating frequency z in operating cycles per hour
Rated operation No-load op. frequency 1/h 10000
for AC-1 1/h 1000
for AC-2 1/h 500
for AC-3 1/h 1000
Conductor cross-sections for designs
with screw connections
Terminal screws M3
Finely stranded with end sleeve (DIN 46 228, style A/D/C) mm2 2 × (0.75 ... 2.5)
Solid mm2 2 × (1 ... 2.5)
mm2 1×4
with tab connectors
Finely stranded 6.3 ... 1 mm2 0.5 ... 1
When using push-on contact acc. to DIN 46 245/46 247 6.3 ... 2.5 mm2 1 ... 2.5
s and u ratings (screw connection)
Rated insulation voltage AC V 600

Conventional thermal Free air and enclosed A 20

current

Maximum horsepower ratings Single-phase 3-phase

(s and u-approved values)
Ratings of three-phase motors at 115 V hp 1/
2 –
at 60 Hz 200 V hp 1 3
230 V hp 11/2 3
460 V/575 V hp – 5
600 V hp – 5

Overload relay Type 3UA7

Setting range A 6.3 ... 10

3/184 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TF68 and 3TF69 vacuum contactors

Technical data

Contactor Size 14 14
Type 3TF68 3TF69
General data
Mechanical endurance operating cycles 5 million
Electrical endurance operating See page 3/182
cycles
Rated insulation voltage Ui V 1 000
(pollution degree 3)
Rated impulse withstand voltage Uimp kV 8
Safe isolation 1) between coil and main contacts V up to 1 000
Permissible ambient temperature in operation °C –25 ... +55
when stored °C –55 ... +80
Degree of protection acc. to IEC 60 947-1 and DIN 40 050 IP 00/open type, control system IP 40
Shock resistance Rectangular pulse AC g/ms 8.1/5 and 4.7/10 9.5/5 and 5.7/10
DC g/ms 9/5 and 5.7/10 8.6/5 and 5.1/10
Sine pulse AC g/ms 12.8/5 and 7.4/10 13.5/5 and 7.8/10
DC g/ms 14.4/5 and 9.1/10 13.5/5 and 7.8/10
Short-circuit protection
Main circuit
Fuse links, utilization category gL/gG
NH Type 3NA, DIAZED Type 5SB, NEOZED Type 5SE
– acc. to IEC 60 947-4/EN 60 947-4-4 Type of coord. "1" 2) A 1 000 1 250
(VDE 0660 Part 102) Type of coord. "2" 2) A 500 630
Weld-free 3) A 400 500
Auxiliary circuit
Fuse links, utilization category gL/gG A 10
(weld-free protection at Ik ≥ 1 kA)
DIAZED Type 5SB, NEOZED Type 5SE
or miniature circuit-breaker with C-characteristic (Ik < 400 A)
Control circuit
Coil voltage tolerance 0.8 Us min ... 1.1 × Us max

Power consumption of the coils (with coil in cold state and 1.0 × Us)
AC operation Hz 50/60 50/60
Us min Us max Us min Us max
closing VA 1200 1850 600 950
p.f. 1 1 0.98 0.98
closed VA 13.5 49 12.9 30.6
p.f. 0.47 0.15 0.43 0.31
DC economy circuit closing 4) W 1010 5) 960 5)
closed W 28 5) 20.6 5)

Operating times at 0.8 ... 1.1 × Us (The values apply with the coil in the cold state and
Break-time = opening time + arcing time at operating temperature)
AC operation closing time ms 70 ... 120 (22 ... 65) 6) 80 ... 120
opening time ms 70 ... 100 70 ... 80
DC economy circuit closing time ms 76 ... 110 86 ... 280
opening time ms 50 19 ... 25
Arcing time ms 10 ... 15 10

Operating times at 1.0 × Us

AC operation closing time ms 80 ... 100 (30 ... 45) 6) 85 ... 100
opening time ms 70 ... 100 70
DC economy circuit closing time ms 80 ... 90 90 ... 125
opening time ms 50 19 ... 25

Minimum command duration for closing standard ms 120 120

shortened operat. time ms 90 –
Minimum interval time between two ON commands ms 100 300

1) Acc. to DIN VDE 0106 Part 101 and A1 Type of coordination "2": 3) Test conditions acc. to IEC 60 947-4-1.
(draft 2/89). No damage can be tolerated to the overload 4) At DC 24 V; deviations up to ± 10 % are possible
2) According to excerpt from relay, but contact welding on the contactor is with other voltages.
IEC 60 947-4 (DIN VDE 0660 Part 102): permitted if the contacts can be easily sepa- 5) Reversing contactor supplied.
Type of coordination "1": rated.
6) The values in brackets apply to contactors with
Destruction of the contactor and the overload shortened operating times.
relay is permissible. The contactor and/or over-
load relay must be replaced if necessary.

Siemens NS K · 2002 3/185

 Contactors and Contactor Assemblies

3TF68 and 3TF69 vacuum contactors

Technical data

Contactor Size 14 14
Type 3TF68 3TF69
Main circuit
Load ratings with AC
AC-1 utilization category, switching resistive load
Rated operational currents Ie at 40 °C up to 690 V A 700 910
at 55 °C up to 690 V A 630 850
at 55 °C up to 1000 V A 450 800
Ratings at 230 V kW 240 323
of three-phase loads with 400 V kW 415 558
p.f. = 1 at 55 °C 500 V kW 545 735
690 V kW 720 970
1000 V kW 780 1385
Minimum conductor cross-sections with Ie load at 40 °C mm2 2 × 240 Ie ≥ 800 A: 2 × 60 × 5
at 55 °C mm2 2 × 185 Ie < 800 A: 2 × 240

AC-2 and AC-3 utilization categories

Rated operational currents Ie up to 690 V A 630 820
1000 V A 435 580
Ratings of slipring or squirrel-cage motors at 50 Hz and at 230 V kW 200 260
60 Hz 400 V kW 347 450
500 V kW 434 600
690 V kW 600 800
1000 V kW 600 800

AC-4 utilization category (at Ia = 6 × Ie)

Rated operational current Ie up to 690 V A 610 690
Ratings of squirrel-cage motors at 400 V kW 355 400
at 50 Hz and 60 Hz
For a contact endurance of approx. 200000 operating cycles:
Rated operational currents Ie up to 690 V A 300 360
1000 V A 210 250
Ratings of squirrel-cage motors at 230 V kW 97 110
at 50 Hz and 60 Hz 400 V kW 168 191

Max. permissible rated operational current

Ie/AC-4 q Ie/AC-3 up to 500 V 500 V kW 210 250
with reduced contact endurance 690 V kW 278 335
and reduced operating frequency 1000 V kW 290 350

AC-6a utilization category,

switching three-phase transformers
with inrush n 30 20 30 20
Rated operational currents Ie up to 400 V A 342 513 450 675
Ratings of three-phase transformers at 230 V kVA 130 195 171 256
with an inrush of n = 30 or 20. 400 V kVA 226 338 297 445
The ratings must be re-calculated 500 V kVA 296 444 389 584
for other inrush factors x: 690 V kVA 390 586 514 771
30 1000 V kVA 592 752 778 1003
Px = Pn 30 ⋅ ------
x

AC-6b utilization category,

switching low-inductance
(low-loss, metallized-dielectric) three-phase capacitors
Rated operational currents Ie up to 400 V A 433
Ratings at 230 V kvar 175
of single capacitors 400 V kvar 300
at 50 Hz, 60 Hz 500 V kvar 400
690 V kvar 300
Ratings of capacitor banks at 230 V kvar 145
(minimum inductance between parallel capacitors 6 µH) 400 V kvar 250
at 50 Hz, 60 Hz 500 V kvar 333
690 V kvar 250

3/186 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TF68 and 3TF69 vacuum contactors

Technical data

Contactor Size 14
Type 3TF68 3TF69
Main circuit
Load ratings with AC
Used as stator contactors (up to 690 V)
(AC-2 utilization category)
Stator currents Ies
Relative ON period 1) 10 % A 1144 1544
with intermittent duty 20 % A 970 1307
40 % A 768 1039
60 % A 690 925
80 % A 630 850

Used as rotor contactors

Rotor currents Ier 3)
Relative ON period 1) 5% A 1900 2500
with intermittent duty 10 % A 1814 2440
20 % A 1530 2065
40 % A 1216 1640
60 % A 1083 1462
80 % A 995 1343
NSB01010 Uninterrupted duty A 995 1343
Locked rotor Starting V 2000 2000
voltages Uer Variable speed V 1000 1000
Plugging V 1000 1000

Short-time current-carrying capacity (5 to 30 s) 10 s current 2) 5040 7000

CLASS 5 and 10 A 630 820
15 A 630 662
20 A 536 572
25 A 479 531
30 A 441 500
Power loss per conducting path at Ie/AC-3/690 V W 45 70
Operating frequency
Operating frequency z Operation: Operation:
AC DC AC DC
Contactors without overload relays No-load operating 1/h 2000 1000 1000 1000
frequency
Dependence of the operating frequency z’ on the for AC-1 1/h 700 700 700 700
operational current I’ and the operational voltage U’: for AC-2 1/h 200 200 200 200
for AC-3 1/h 500 500 500 500
z’ = z ⋅ ---- ⋅ ----------  1/h.
Ie 400 V 1.5 for AC-4 1/h 150 150 150 150
I′  U ′ 
Contactors with overload relays (mean value) 1/h 15 15
Conductor cross-sections
Screw connection Main conductor:
– Busbar connection
Finely stranded with cable lug mm2 50 ... 240 50 ... 240
Stranded with cable lug mm2 70 ... 240 70 ... 240
Solid or stranded AWG 2/0 ... 500 MCM 2/0 ... 500 MCM
Connecting bar (max. width) mm max. 50 Max. 60 (Ue ≤ 690 V)
50 (Ue > 690 V)
Terminal screw M 10 × 30 M 12 × 40
Tightening torque 14 ... 24 Nm 20 ... 35 Nm
(124 ... 210 lb.in) (177 ... 310 lb.in)
– With box terminal 4)
Connection for laminated copper bars
Width mm 15 ... 25 15 ... 38
Max. thickness mm 1 × 26 or 2 × 11 1 × 46 or 2 × 18
Terminal screw, hexagon socket mm 6 8
Tightening torque 25 ... 40 Nm 35 ... 50 Nm
(221 ... 354 lb.in) (266 ... 443 lb.in)

Auxiliary conductor:
Solid mm2 2 × (0.5 ... 1); 2 × (1 ... 2.5)
Finely stranded with end sleeve mm2 2 × (0.5 ... 1); 2 × (0.75 ... 2.5)
Pin-end connector (DIN 46 231) mm2 2 × (1 ... 1.5)
Solid or stranded AWG 2 × (18 ... 12)
Tightening torque 0.8 ... 1.4 Nm
(7 ... 12 lb.in)

1) Relative ON period in % = 2) Acc. to DIN VDE 0660, Part 102.

ON period 3) Conductor currents in the supply lead to the
× 100, cycle times up to 10 min.
Cycle time contactor.
Max. operating frequency z = 50 1/h; with higher 4) See accessories on page 3/173.
operating frequencies z the following equation
must be used for the calculation: Ioff ~ 1/z.

Siemens NS K · 2002 3/187

 Contactors and Contactor Assemblies

3TF68 and 3TF69 vacuum contactors

Technical data

Contactor Size 14
Type 3TF68 3TF69

s and u ratings
Rated insulation voltage AC V 600 600

Conventional thermal Free air and enclosed A 630 820

current

Maximum horsepower ratings

(s and u-approved values)
Ratings of three-phase motors at 200 V hp 231 290
at 60 Hz 230 V hp 266 350
460 V hp 530 700
575 V hp 664 860

NEMA/EEMAC ratings SIZE 6 7

Conventional thermal current Free air A 600 820
Enclosed A 540 810
Ratings of three-phase motors at 200 V hp 150 –
at 60 Hz 230 V hp 200 300
460 V hp 400 600
575 V hp 400 600

Overload relay Type 3RB12

Setting range A 200 ... 820

For short-circuit protection with overload relays, see Part 4.

3/188 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TB50 to 3TB56 contactors

Technical data

Contactor Size 6 8 10 12
Type 3TB50 3TB52 3TB54 3TB56
General data
Mechanical endurance operating cycles 10 million

Electrical endurance operating cycles See page 3/181

Rated insulation voltage V 1000

Safe isolation 1) between coil and main contacts V 690

Permissible ambient temperature in operation °C –25 ... +55

when stored °C –50 ... +80

Degree of protection IP 00 (open type), control system IP 40

acc. to IEC 60 947-1 and DIN 40 050

Shock resistance (rectangular pulse) g/ms 5/10 5.9/10 5.9/10 5.9/10

Short-circuit protection
Main circuit
Fuse links NH Type 3NA
Utilization category gL/gG DIAZED Type 5SB
I 2) A 125 160 200 315
II 3) A 224 250 315 500

Auxiliary circuit (short-circuit current Ik ≥ 1 kA)

Fuse links DIAZED Type 5SB A 16
Utilization category gL/gG NEOZED Type 5SE
Miniature circuit-breaker with C-characteristic A 10

Control circuit
Coil voltage tolerance 0.8 ... 1.1 × rated control supply voltage

Power consumption of the coils (with coil in cold state and 1.0 × Us)
closing = closed W 25 30 60 86

Operating times at 0.8 ... 1.1 × Us (The values apply up to and including 20 % undervoltage and
Break-time = opening time + arcing time 10 % overvoltage, and with the coil in the cold state and at operating
temperature)
closing time ms 105 ... 360 115 ... 400 105 ... 400 110 ... 400
opening time 4) ms 18 ... 30 22 ... 35 24 ... 55 40 ... 110
arcing time ms 10 ... 15 10 ... 15 10 ... 15 10 ... 15

Operating times at 1.0 × Us

closing time ms 120 ... 230 130 ... 250 115 ... 250 120 ... 250
opening time 4) ms 20 ... 26 24 ... 32 35 ... 50 60 ... 95
Main circuit
Load ratings with AC
AC-1 utilization category, switching resistive load
Rated operational current Ie at 40 °C A 170 230 325 425
at 55 °C A 160 200 300 400
Ratings of three-phase loads 5) 230 V kW 61 76 114 152
p.f. = 0.95 (at 55 °C) 400 V kW 105 132 195 262
500 V kW 138 173 260 345
690 V kW 183 228 340 455
Minimum conductor cross-section with Ie load mm2 70 95 185 240

AC-2 and AC-3 utilization categories

Slipring or squirrel-cage motors See selection tables on page 3/165

AC-4 utilization category 6)

Rated operational current Ie A 52 72 103 120
Ratings of squirrel-cage motors 230 V kW 15.6 21 31 37.5
at 50 Hz and Ia = 6 × Ie 400 V kW 27 37 55 65
500 V kW 35 48 72 85.5
690 V kW 45 64 92 106
Max. permissible rated operational current Ie/AC-4 at 400 V A 110 170 250 400

1) Acc. to DIN VDE 0106 Part 101 and A1 4) The opening times may increase if the contactor 6) The contact endurance (approximately 200 000
(draft 2/89). coils are protected against voltage peaks. operating cycles) has been rated for typical
2) Completely weld-free. 5) Industrial furnaces and electric heaters with applications; see characteristic curves on
3) Slight, separable contact welding, no further resistance heating, for example (higher current page 3/181.
damage. input allowed for during heating up).

Siemens NS K · 2002 3/189

 Contactors and Contactor Assemblies

3TB50 to 3TB56 contactors

Technical data

Contactor Size 6 8 10 12
Type 3TB50 3TB52 3TB54 3TB56
Main circuit
Load ratings with AC
Switching low-inductance (low-loss,
metallized-dielectric) three-phase capacitors 1)
Rated operational current Ie at 400 V A 87 144 217 289
Ratings of 230 V kvar 35 58 87 115
individual capacitors at 50 Hz 400 V kvar 60 100 150 200
500 V kvar 80 130 190 265
690 V kvar 60 100 150 200
Ratings of capacitor banks (minimum 230 V kvar 30 40 66 85
inductance between parallel capacitors 400 V kvar 50 70 115 150
6 µH) at 50 Hz 500 V kvar 66 90 145 195
690 V kvar 50 70 115 150

Used as stator contactors

(AC-2 utilization category)
Stator current Ies 2)
Relative ON period 3) 20 % A 245 308 462 617
with intermittent duty 40 % A 195 245 367 490
60 % A 174 218 327 436
80 % A 160 200 300 400

Used as rotor contactors

Rotor current Ier 2)
Relative ON period 3) 10 % A 395 560 759 1075
with intermittent duty 20 % A 388 487 730 975
40 % A 308 387 580 775
60 % A 275 345 517 689
80 % A 252 316 474 632

NSB01010 Uninterrupted duty A 252 316 474 632

Locked rotor voltages Uer Starting V 2000 2000 2000 2000
Variable speed V 1000 1000 1000 1000
Plugging V 1000 1000 1000 1000
Load ratings with DC
DC-1 utilization category, switching resistive load
(L/R ≤ 1 ms)

Rated operational current Ie (at 55 °C)

Number of conducting paths connected in series 1 2 3 1 2 3 1 2 3 1 2 3
24 V A 160 160 160 200 200 200 300 300 300 400 400 400
60 V A 80 160 160 80 200 200 300 300 300 330 400 400
110 V A 18 160 160 18 200 200 33 300 300 33 400 400
220 V A 3.4 20 160 3.4 20 200 3.8 300 300 3.8 400 400
440 V A 0.8 3.2 11.5 0.8 3.2 11.5 0.9 4 11 0.9 4 11
600 V A 0.5 1.6 4 0.5 1.6 4 0.6 2 5.2 0.6 2 5.2

DC-2 to DC-5 utilization categories, shunt and

series motors (L/R ≤ 15 ms)

Rated operational current Ie (at 55 °C)

Number of conducting paths connected in series 1 2 3 1 2 3 1 2 3 1 2 3
24 V A 16 160 160 16 200 200 35 300 300 35 400 400
60 V A 7.5 160 160 7.5 200 200 11 300 300 11 400 400
110 V A 2.5 160 160 2.5 200 200 3 300 300 3 400 400
220 V A 0.6 2.5 160 0.6 2.5 200 0.6 2.5 300 0.6 2.5 400
440 V A 0.17 0.65 1.4 0.17 0.65 1.4 0.18 0.65 1.4 0.18 0.65 1.4
600 V A 0.12 0.37 0.75 0.12 0.37 0.75 0.125 0.37 0.75 0.125 0.37 0.75
Operating frequency
Operating frequency in operating cycles
per hour
Contactors without overload for AC-1 1/h 1000
relays
Rated operation for AC-2 and AC-3 1/h 500
for AC-4 1/h 250
Contactors with overload relays (mean value) 1/h 15

1) Contact endurance 0.1 million operating cycles. 3) Relative ON period in % =

2) For contact endurance at these loads, ON period
× 100, cycle times up to 10 min.
see characteristic curves on page 3/181. Cycle time

3/190 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TB50 to 3TB56 contactors

Technical data

Contactor Size 6 8 10 12
Type 3TB50 3TB52 3TB54 3TB56
Conductor cross-sections
Screw connection Main conductor:
Finely stranded with cable lug mm2 16 ... 70 35 ... 95 50 ... 240 50 ... 240
Stranded with cable lug mm2 25 ... 70 50 ... 120 70 ... 240 70 ... 240
Busbars mm 15 × 3 20 × 3 25 × 5 2 × (25 × 3)
Terminal screw M6 M8 M 10 M 10
Auxiliary conductor:
Solid mm2 1 ... 2.5
Finely stranded with end sleeve mm2 0.75 ... 1.5
Pin-end connector (DIN 46 231) mm2 2 × 1 ... 2.5
Protective conductor:
Stranded with cable lug mm2 – 25 ... 70 35 ... 70 50 ... 120

s and U ratings
s Conventional thermal current Free air A 150 170 240 300
Enclosed A 135 153 215 270
Ratings of three-phase motors 115 V hp 25 30 40 50
at 60 Hz (enclosed) 230 V hp 50 60 75 100
460 V hp 100 120 150 200
575 V hp 125 160 200 250
Overload relay Type 3RB1056 3RB1056 3RB1066 3RB1066
Setting range A 50 ... 200 50 ... 200 50 ... 250 200 ... 540
EEMAC SIZE contactors Size 4 4 4 5
Starters (contactors and overload relays, enclosed) Size 3 4 4 5

u Conventional thermal current Free air A 150 150 240 390

and Enclosed A 135 135 215 350
U Ratings of three-phase motors 115 V hp 25 25 30 –
at 60 Hz (enclosed) 230 V hp 50 50 75 125
460 V hp 100 100 150 250
575 V hp 125 125 200 300 1)
Overload relay Type 3RB1056 3RB1056 3RB1066 3RB1066
Setting range A 50 ... 200 50 ... 200 50 ... 250 200 ... 540
NEMA SIZE contactors Size 4 4 4 5
Starters (= contactors + overload relays, enclosed) Size 3 4 4 5

Specified short-circuit protection devices (u-approved):

Fuses Class RK5 RK5 RK5 RK5
A 400 400 450 600
Circuit-breakers A 175 175 250 600

1) Max. rated motor current 325 A and motor

starting current 3250 A at AC 575 V (AC 600 V).

Siemens NS K · 2002 3/191

 Contactors and Contactor Assemblies

3TD68 contactor assemblies

Technical data

Contactor Size 14
Type 3TD68

s and u ratings
Rated insulation voltage AC V 600

Conventional thermal current Enclosed A 550

Maximum horsepower ratings

(s and u-approved values)
Ratings of three-phase motors at 60 Hz at 200 V hp 200
230 V hp 229
460 V hp 464
575 V hp 582

NEMA/EEMAC ratings
NEMA/EEMAC SIZE 6
Conventional thermal current Free air A 600
Enclosed A 540
Ratings of three-phase motors at 60 Hz at 200 V hp 150
230 V hp 200
460 V hp 400
575 V hp 400

Overload relay Type 3RB10

Setting range A 300 ... 630

For short-circuit protection with overload relays, see Part 4.

The technical data is identical to that of the 3TF68 and 3TF69 contactors listed on pages 3/179 and 3/185 to 3/188.
The mechanical endurance is 5 million operating cycles for 3TD68.
For the unassigned auxiliary contacts of the contactors, see the circuit diagrams of the control circuits on page 3/204.
The s and u approvals only apply to the complete contactor assemblies and not to the components for customer assembly.

3/192 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TE68 contactor assemblies

Technical data

Starters Type 3TE68

Mechanical endurance operating cycles 3 million

Size of contactors Line K1 Type 3TF68

Delta K3 Type 3TF68
Star K2 Type 3TF56

Unassigned auxiliary contacts of the contactors 1)

Current-carrying capacity with reversing time up to 10 s

Rated operational current up to 690 V A 1090
Ratings at 230 V kW 355
of three-phase motors 400 V kW 612
at 50 Hz and 500 V kW 800
690 V kW 1046
Operating frequency with overload relay 1/h 3

Current-carrying capacity with reversing time up to 15 s

Rated operational current up to 500 V A 923
690 V A 883
Ratings at 230 V kW 295
of three-phase motors 400 V kW 515
at 50 Hz 500 V kW 677
690 V kW 885
Operating frequency with overload relay 1/h 2

Current-carrying capacity with reversing time up to 20 s

Rated operational current up to 500 V A 800
690 V A 765
Ratings at 230 V kW 244
of three-phase motors 400 V kW 444
at 50 Hz 500 V kW 590
690 V kW 770
Operating frequency with overload relay 1/h 2

Short-circuit protection
Main circuit
Fuse links, utilization category gL/gG
NH Type 3NA, DIAZED Type 5SB, NEOZED Type 5SE
– acc. to IEC 60 947-4-1/EN 60 947-4 (VDE 0660 Part 102)
Type of coord. "1" A 1000
Type of coord. "2" A 500 2)

Auxiliary circuit
Fuse links, utilization category gL/gG A 10
(weld-free protection at Ik ≥ 1 kA)
DIAZED Type 5SB, NEOZED Type 5SE
or miniature circuit-breaker with C-characteristic (Ik < 400 A)

Short-circuit protection with fuses for motor feeders with short-circuit currents up to 50 kA and 690 V
Contactor Rated motor Overload Current setting range Permissible short-circuit fuses for starters, comprising contactor assemblies and overload
assembly current relay (the overload relays relays. Single or double infeed 2)
must be set to 0.58 Fuse links
times the rated motor NH Type 3NA NH TYPE 3ND Siemens u-listed British Standard fuses
current) DIAZED Type 5SB Utilization category Canada fuses BS88
NEOZED Type 5SE aM fuses HRC CLASS RK5
Style II
Type of coordination Type of coordination Type of coordination
"1" "2" "2" "1" "2"
Type A Type A A A A A A A A

3TE68 346 ... 935 3RB10 66 200 ... 540 1000 500 630 1000 1200 1000 500
520 ... 1090 3RB10 66 300 ... 630 CLASS L

For short-circuit protection with overload relays, see Part 4.

Use a double infeed for higher rated motor currents
(see circuit diagram on page 3/205).

1) See the circuit diagrams of the control circuits on 2) The maximum rated motor current must not be
page 3/204. exceeded.

Siemens NS K · 2002 3/193

 Contactors and Contactor Assemblies

3TK10 to 3TK17 contactors

Technical data

Contactor Type 3TK10 3TK11 3TK12 3TK13 3TK14 3TK15 3TK17

General data
Mechanical endurance operating mill. 10 5
cycles

Electrical endurance operating mill. 0.8 0.8 0.8 0.4 0.65 0.5 0.4
at Ie/AC-1 and 55 °C cycles

Rated insulation voltage Ui V 1000

(pollution degree 3)

Permissible ambient temperature

in operation °C –25 ... +55
when stored °C –50 ... +70

Degree of protection IP 00
acc. to IEC 60 947-1 and DIN 40 050

Shock resistance Sine pulse g/ms 10/15

Short-circuit protection
Main circuit
Fuse links, utilization category gL/gG

NH Type 3NA
DIAZED Type 5SB
NEOZED Type 5SE
– acc. to IEC 60 947-4-1 Type of coord. "1" A 250 355 800 1000
(DIN VDE 0660 Part 102) Type of coord. "2" A 250 315 630 850

Auxiliary circuit
(Short-circuit current Ik ≥ 1 kA)
Fuse links, utilization category gL/gG
DIAZED Type 5SB A 10
NEOZED Type 5SE A 10
Control circuit
Coil voltage tolerance 0.85 ... 1.1 × Us

Power consumption of the coils

(with coil in cold state and 1.0 × Us) Hz 50 60 50 60 50 60

closing VA 820 990 1100 1200 3500 4000

p.f. 0.4 0.35 0.35 0.31 0.26 0.22
closed VA 44 52 52 65 125 140
p.f. 0.34 0.35 0.35 0.34 0.4 0.43

Operating times at 1.0 × Us

Break-time = opening time + arcing time
closing time ms 20 ... 40 30 ... 60
opening time ms 7 ... 15 10 ... 20
Arcing time ms 10 ... 15 10 ... 15

3/194 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TK10 to 3TK17 contactors

Technical data

Contactor Type 3TK10 3TK11 3TK12 3TK13 3TK14 3TK15 3TK17

Main circuit
Load ratings with AC
AC-1 utilization category,
switching resistive load
Rated operational currents Ie at 40 °C up to 690 V A 200 250 300 350 550 800 1000
at 55 °C up to 690 V A 180 230 270 310 470 650 850
Ratings at 230 V kW 76 95 114 132 208 303 378
of three-phase loads 400 V kW 132 165 197 230 362 527 658
p.f. = 0.95 (at 40 °C) 500 V kW 165 206 247 288 452 658 828
690 V kW 227 284 341 397 624 908 1135
Minimum conductor cross-section at 40 °C mm2 95 150 185 240 2 × 185 2 × 240 2 × 300
with Ie load

AC-2 and AC-3 utilization categories

Rated operational currents Ie (at 55 °C) up to 400 V A 120 145 210 210 400 550 700
Ratings of motors at 230 V kW 30 45 75 75 110 160 220
with slipring or squirrel-cage rotor 400 V kW 55 75 110 110 200 280 370
at 50 Hz and 60 Hz

Short-time current at 40 °C in cold state up to 10 s A 900 1200 1600 1600 5300 5300 6400

Operating frequency
Operating frequency z
Contactors without No-load operating frequency 1/h 3600
overload relays for AC-1 1/h 300
for AC-3 1/h 300
Dependence of the operating frequency z’ on the
operational current I’ and the operational voltage U’:

z’ = z ⋅ ---- ⋅ ----------  1/h

Ie 400 V 1.5
I′  U ′ 

Conductor cross-sections
Main conductor:
Stranded with cable lug mm2 2 × 70 2 × 120 2 × 120 2 × 300
Solid or stranded AWG MCM 2 × 00 2 × 250 2 × 250 2 × 600
Connecting bars (max. width) mm 30 30 33 55
Terminal screw M6 M 10 M 10 M 10
Tightening torque Nm 5 16 16 16
lb. in 42 135 135 135
Auxiliary conductor:
Solid mm2 2 × (0.5 ... 2.5)
Finely stranded with end sleeve mm2 2 × (0.5 ... 2.5)
Solid or stranded AWG MCM 2 × (20 ... 14)
Tightening torque Nm 1.2
lb. in 10

Siemens NS K · 2002 3/195

 Contactors and Contactor Assemblies

3TC44 to 3TC56 contactors

Technical data

Contactor Size 2 4 8 12
Type 3TC44 3TC48 3TC52 3TC56
General data
Mechanical endurance operating cycles 10 million

Electrical endurance operating cycles See page 3/182

Rated insulation voltage Ui V 800 1000

(pollution degree 3)

Safe isolation between coil and main contacts V up to 300 up to 660

acc. to DIN VDE 0106 Part 101 and A1 (draft 2/89)

Permissible ambient temperature in operation °C –25 ... +55

when stored °C –50 ... +80

Degree of protection acc. to IEC 60 947-1 and DIN 40 050 IP 00/open type, with AC operation, control system IP 40

Shock resistance Rectangular pulse g/ms 7.5/5 and 3.4/10 10/5 and 5/10 12/5 and 5.5/10 12/5 and 5.6/10
Control circuit
Coil voltage tolerance 0.8 ... 1.1 × Us

Power consumption of the coils

(with coil in cold state and 1.0 × Us)
DC operation closing = closed W 10 19 30 86

AC operation Hz 50 50/60 60 50/60 50 60 50 60 50 60

(at (at
50 Hz) 60 Hz)
closing VA 68 79 95 73 300 365 640 730 1780 2140
p.f. 0.86 0.83 0.79 0.78 0.5 0.45 0.48 0.38 0.30 0.30
closed VA 10 11 12 9 26 35 46 56 121 140
p.f. 0.29 0.28 0.3 0.27 0.24 0.26 0.23 0.24 0.22 0.29
Operating times (The values apply up to and including 20 % undervoltage and 10 % overvoltage,
Break-time = opening time + arcing time and with the coil in the cold state and at operating temperature)
DC operation closing time ms 35 ... 190 90 ... 380 120 ... 400 110 ... 400
opening time 1) ms 10 ... 25 17 ... 28 22 ... 35 40 ... 110
AC operation closing time ms 10 ... 40 20 ... 50 20 ... 50 20 ... 50
opening time 1) ms 5 ... 25 5 ... 30 10 ... 30 10 ... 30
Arcing time DC-1 ms 20
DC-3/5 ms 30
Short-circuit protection of contactors
Main circuit
Fuse links, utilization cate- NH Type
gory gL/gG 3NA
DIAZED Type
5SB
NEOZED Type
5SE
I 2) A 35 63 80 250
II 3) A 50 160 250 400

Auxiliary circuit
(Short-circuit current Ik ≥ 1 kA)
Fuse links, DIAZED Type A 16
utilization category gL/gG 5SB
NEOZED Type 5SE
Miniature circuit-breaker with C-characteristic A 10

1) The opening times may increase if the contactor 2) Completely weld-free.

coils are protected against voltage peaks. Only 3) Slight, separable contact welding, no further
3TC44 contactors are allowed to be fitted with damage.
diodes.

3/196 Siemens NS K · 2002

 Contactors and Contactor Assemblies

3TC44 to 3TC56 contactors

Technical data

Contactor Size 2 4 8 12
Type 3TC44 3TC48 3TC52 3TC56
Main circuit
Load ratings with DC
DC-1 utilization category, switching resistive load (L/R ≤ 1 ms)
Rated operational currents Ie (at 55 °C) up to Ue 750 V A 32 75 220 400
Minimum conductor cross-section mm2 6 25 95 240
Rating at Ue 220 V kW 7 16.5 48 88
440 V kW 14 33 97 176
600 V kW 19.2 45 132 240
750 V kW 24 56 165 300

DC-3 and DC-5 utilization categories,

shunt and series motors (L/R ≤ 15 ms)
Rated operational currents Ie (at 55 °C) up to Ue 220 V A 32 75 220 400
440 V A 29 75 220 400
600 V A 21 75 220 400
750 V A 7.5 75 170 400
Rating at Ue 110 V kW 2.5 6.5 20 35
220 V kW 5 13 41 70
440 V kW 9 27 82 140
600 V kW 9 38 110 200
750 V kW 4 45 110 250
Operating frequency
Operating frequency z
DC and AC operation with resistive load
DC-1 utilization category 1/h 1500 1000
with inductive load
DC-3 and DC-5 utilization categories 1/h 750 600
Conductor cross-sections
Screw connection Main conductor:
(1 or 2 conductor Solid mm2 2 × (2.5 ... 10) – – –
connections possible) Finely stranded with end sleeves mm2 2 × (1.5 ... 4) – – –
Stranded with cable lug mm2 – 2 × 35 2 × 120 2 × 150
Pin-end connector (DIN 46 231) mm2 2 × 1 ... 6 – – –
Busbars mm – 15 × 2.5 25 × 4 2 × (25 × 3)
Terminal screw M5 M6 M 10 M 10
Auxiliary conductor:
Solid mm2 2 × (1 ... 2.5)
Finely stranded with end sleeve mm2 2 × (0.75 ... 1.5)

Siemens NS K · 2002 3/197

 Contactors and Contactor Assemblies

3TC74, 3TC78 contactors

Technical data

Contactor Type Single-pole contactors 2-pole contactors

3TC74 3TC78
General data
Mechanical endurance operating cycles 30 million
Electrical endurance operating cycles See page 3/182

Rated insulation voltage Ui (pollution degree 3) V 1500

Rated impulse withstand voltage Uimp kV 8
Safe isolation between coil and main contacts V up to 630
acc. to DIN VDE 0106 Part 101 and A1 (draft 2/89)
Permissible ambient temperature °C –25 ... +55
Degree of protection acc. to IEC 60 947-1 and DIN 40 050 IP 00/open type
Short-circuit protection
Main circuit
Fuse links, utilization category gL/gG NH Type 3NA A 500
Auxiliary circuit (short-circuit current Ik ≥ 1 kA)
Fuse links, utilization category gL/gG DIAZED Type 5SB A 16
NEOZED Type 5SE
Miniature circuit-breaker with C-characteristic A 10
Control circuit
Coil voltage tolerance
DC operation 24 V 0.8 ... 1.2 × Us
> 24 V 0.7 ... 1.2 × Us
AC operation 24 V 0.7 ... 1.15 × Us
> 24 V 0.7 ... 1.2 × Us
Power consumption of the coils (with coil in cold state and 1.0 × Us)
DC operation closing = closed W 46 92
AC operation closing / p.f. VA 80 / 0.95 160 / 0.95
closed / p.f. VA 80 / 0.92 160 / 0.92
Operating times (The values apply up to and including 15 % undervoltage and
Break-time = opening time + arcing time 10 % overvoltage, and with the coil in the cold state and at operating
temperature)
DC and AC operation closing time ms 60 ... 100
opening time ms 20 ... 35
arcing time at 0.06 ... 4 × Ie ms 40 ... 70
Main circuit
Load ratings with DC
DC-1 utilization category, switching resistive load (L/R ≤ 1 ms)
Rated operational current Ie/DC-1 (at 55 °C) A 500 500
Minimum conductor cross-section mm2 2 × 150 2 × 150
Ratings at 220 V kW 110 110
440 V kW 220 220
600 V kW 300 300
750 V kW 375 375
1200 V kW – 600
1500 V kW – 750
Critical currents at which 440 V A ≤ 7 –
the arc is not extinguished 600 V A ≤ 13 –
750 V A ≤ 15 –
≤ 880 V A – ≤ 7
1200 V A – ≤ 13
1500 V A – ≤ 15
DC-3 and DC-5 utilization categories, switching DC motors See selection tables on page 3/168
Permissible rated current for plugging at 110 V ... 600 V A 400
Operating frequency
Operating frequency
DC and AC operation with resistive load, DC-1 utilization category 1/h 750 1000
with inductive load, DC-3 and DC-5 utilization
categories 1/h 500 500
Conductor cross-sections
Screw connection Main conductor:
Stranded with cable lug mm2 2 × up to 150
Busbars mm 2 × (30 × 4)
Auxiliary conductor:
Solid mm2 1 ... 2.5
Finely stranded with end sleeve mm2 0.75 ... 1.5

3/198 Siemens NS K · 2002