Brochure
SENTRON
switch disconnectors 3KA/3KE:
Switching without fuses.
Standards IEC 60947-1, IEC 60947-3, VDE 0660 Part 107
Disconnector Type 3KA50 3KA51 3KA52 3KA53 3KA55 3KA57 3KA58
Rated continuous current I
u
A 63 80 125 160 250 400 630
Rated operating voltage U
e
50 Hz/60 Hz AC V 690
DC V 440 (3 conducting paths connected in series)
V 220 (2 conducting paths connected in series)
Rated short-circuit making capacity
with upstream fuses
at 690 V AC 50Hz/60 Hz kA (peak value) 220 220 220 220 220 220 220
Rated conditional short-circuit current
with upstream fuses
at 690 V AC 50 Hz/60 Hz kA (peak value) 100 100 100 100 80 80 50
Max. rated current I
n
of the fuses A 63 80 160 160 400 400 630
Permissible let-through current of fuses kA 8 10 17 17 30 30 40
Max. permissible I
2
t let-through value kA
2
s 55 55 223 223 1000 1000 2600
Switching capacity (feed from either the top or bottom)
at 400 V AC
Breaking current I
c
(cos = 0.35) A (RMS value) 500 650 1000 1280 2000 3200 5040
AC-21A, AC-22A, AC-23A A 63 80 125 160 250 400 630
Motor switching capacity AC-23A kW 30 40 65 80 132 200 350
at 500 V AC
Breaking current I
c
(cos = 0.35) A (RMS value) 500 640 1000 1280 2000 3200 3200
Rated operating current I
e
at
AC-21A, AC-22A A 63 80 160 250 400 630
AC-23A A 63 80 125 160 250 400 400
Motor switching capacity AC-23A kW 40 50 90 110 185 280 280
at 690 V AC
Breaking current I
c
(cos = 0.35) A (RMS value) 500 500 1000 1280 2000 3200 3200
Rated operating current I
e
at
AC-21A, AC-22A A 63 80 125 160 250 400 630
AC-23A A 63 63 125 160 250 400 400
Motor switching capacity AC-23A kW 50 50 110 150 220 375 375
at 440 V DC (3 conducting paths connected in series)
Breaking current I
c
(L/R = 15 ms) A (RMS value) 250 260 500 640 1000 1600 1600
Rated operating current I
e
for DC-23A A 63 63 125 160 250 400 400
Technical data: Switch disconnectors 3KA
8 l 9
The specialists for fuseless disconnection
These switch disconnectors without fuses are used in distribution systems in residential
and commercial buildings as well as in industrial switchboards. Switch disconnectors
3KA and 3KE reliably ”isolate” and ”switch under load” the specified rated current
through either three or four phases. This means that they are predestined as main
control, EMERGENCY-STOP, repair or line changeover switch – and they guarantee safe
isolation in all low-voltage networks.