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3VT3 Molded Case Circuit Breakers up to 630 A
Overcurrent releases
4/22
Siemens LV 36 · 2008
4
Overcurrent releases ETU MPS-Motors, setting timing selectivity
• Direct protection for motors and generators
• Possibility for protecting lines and transformers
• Enables adjusting time delay of independent release
The 3VT9 3..-6AS00 release is intended for 3VT3763-.AA36-
0AA0 and 3VT3763-.AA46-0AA0 switching units. The operation
of the release is controlled by a microprocessor. The release is
equipped with a thermal memory that can be disabled by turn-
ing a switch on the front panel from position T
(t)
to position T
(0)
.
After disabling of the thermal memory, the thermal release re-
mains active.
When one or two phases fail (due to current greater than
I
r
in the
remaining phases), in the M-characteristic mode, the switch will
open with a 4 s delay (so-called undercurrent release).
Another parameter for adjusting the release consists of the rated
current and tripping level of the delayed short-circuit release.
The time delay (t
v
) can be set on the delayed short-circuit
release at 0, 100, 200 or 300 ms. The operational state 70% of
I
r
is signalled by an LED indicator that flashes green in a 1.5 s in-
terval. As the load grows, the blinking frequency of the diode in-
creases. In case of a load larger than 110% of
I
r
, this LED will
turn red and just before tripping will begin to blink red. On the
lower part of the release cover are two photocells for communi-
cating with the prospective signalling unit.
The releases have tripping characteristics especially designed
for practical purposes that provide for optimal exploitation of
transformers up to 1.5
I
r
. A total of 8 characteristics can be set
on the release. Mode “M” provides 4 characteristics suitable for
protecting motors, and in mode “TV” are 4 characteristics for
protecting transformers and lines. The shape of each character-
istic can be changed using a selector switch.
Adjustable specifications
Order No.
Rated
current
I
n
Overload
protection
I
r
t
r
(7.2 x
I
r
) Restart Instanta-
neous
short
circuit
protection
I
i
A A
S
kA
ms
100
1 (TV 1)
T
(0)
3
110
3 (TV 3)
T
(0)
5
0
115
10 (TV 10) T
(0)
7
125
20 (TV 20) T
(0)
9
137
20 (M 20) T
(0)
3
144
15 (M 15) T
(0)
5
100
160
8 (M 8)
T
(0)
7
3VT9 325-6AS00 250 172
3 (M 3)
T
(0)
9
180
3 (M 3)
T
(t)
3
190
8 (M 8)
T
(t)
5
200
200
15 (M 15) T
(t)
7
210
20 (M 20) T
(t)
9
220
20 (TV 20) T
(t)
3
231
10 (TV 10) T
(t)
5
300
243
3 (TV 3)
T
(t)
7
250
1 (TV 1)
T
(t)
9
160
1 (TV 1)
T
(0)
3
172
3 (TV 3)
T
(0)
5
0
180
10 (TV 10) T
(0)
7
190
20 (TV 20) T
(0)
9
200
20 (M 20) T
(0)
3
210
15 (M 15) T
(0)
5
100
220
8 (M 8)
T
(0)
7
3VT9 340-6AS00 400 231
3 (M 3)
T
(0)
9
243
3 (M 3)
T
(t)
3
250
8 (M 8)
T
(t)
5
200
275
15 (M 15) T
(t)
7
290
20 (M 20) T
(t)
9
315
20 (TV 20) T
(t)
3
345
10 (TV 10) T
(t)
5
300
360
3 (TV 3)
T
(t)
7
400
1 (TV 1)
T
(t)
9
250
1 (TV 1)
T
(0)
3
260
3 (TV 3)
T
(0)
5
0
275
10 (TV 10) T
(0)
7
290
20 (TV 20) T
(0)
9
305
20 (M 20) T
(0)
3
315
15 (M 15) T
(0)
5
100
345
8 (M 8)
T
(0)
7
3VT9 363-6AS00 630 360
3 (M 3)
T
(0)
9
400
3 (M 3)
T
(t)
3
435
8 (M 8)
T
(t)
5
200
455
15 (M 15) T
(t)
7
480
20 (M 20) T
(t)
9
500
20 (TV 20) T
(t)
3
550
10 (TV 10) T
(t)
5
300
575
3 (TV 3)
T
(t)
7
630
1 (TV 1)
T
(t)
9