SIEMENS
3/126
Siemens IC 10 · 2017
Power Contactors for Switching Motors
SIRIUS 3RT12 and 3TF6 vacuum contactors
3
Vacuum contactors
Type
3TF68 and 3TF69
Size
14
Rated data of the auxiliary contacts
According to IEC 60947-5-1
Rated insulation voltage
U
i
(pollution degree 3)
V
690
Conventional thermal current
I
th
= rated operational current
I
e
/AC-12
A
10
AC load
Rated operational current
I
e
/AC-15/AC-14
• For rated operational voltage
U
e
-
At 24 V
A
10
-
At 110 V
A
10
-
At 125 V
A
10
-
At 220 V
A
6
-
At 230 V
A
5.6
-
At 380 V
A
4
-
At 400 V
A
3.6
-
At 500 V
A
2.5
-
At 660 V
A
2.5
-
At 690 V
A
2.3
DC load
Rated operational current
I
e
/DC-12
• For rated operational voltage
U
e
-
At 24 V
A
10
-
At 60 V
A
10
-
At 110 V
A
3.2
-
At 125 V
A
2.5
-
At 220 V
A
0.9
-
At 440 V
A
0.33
-
At 600 V
A
0.22
Rated operational current
I
e
/DC-13
• For rated operational voltage
U
e
Auxiliary contacts with
delayed NC contact:
NS = No specification
-
At 24 V
A
10
6
-
At 60 V
A
5
N S
-
At 110 V
A
1.14
0.98
-
At 125 V
A
0.98
N S
-
At 220 V
A
0.48
N S
-
At 440 V
A
0.13
N S
-
At 600 V
A
0.07
0.07
s
and
u
rated data of the auxiliary contacts
Rated voltage, max.
V AC
600
Switching capacity
A 600, P 600
Endurance of the auxiliary contacts
The contact endurance for utilization category
AC-12 or AC-15/AC-14 depends mainly on the
breaking current. It is assumed that the operat-
ing mechanisms are switched randomly, i. e. not
synchronized with the phase angle of the supply
system.
The characteristic curves apply to 230 V AC.
Contact erosion indication with vacuum
contactors
The contact erosion of the vacuum interrupters
can be checked during operation with the help
of three white double slides on the contactor
base.
If the distance indicated by one of the double
slides is < 0.5 mm while the contactor is in the
closed position, the vacuum interrupter must be
replaced. To ensure maximum reliability, it is
recommended to replace all three vacuum
interrupters at once.
4
3
2
10
8
6
4
3
2
10
8
6
4
3
2
10
7
6
5
10
2
3
4
6 8 10
2
3
4
6 8 10
2
3
4
6 8 10
2
-2
-1
0
1
a
NSB0_00651b
(A)
Operating cycles
Breaking current
© Siemens AG 2016