Protection Against Instantaneous Short-Circuit "Iinst; Summary Table Of Protections - ABB Tmax T7 Operating Instructions Manual
T7-t8-x1 low voltage air circuit breakers protection releases
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Also See for Tmax T7:
- Quick start manual (4 pages) ,
- Installation directions manual (17 pages)
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WARNING: In some installations, where particularly high harmonics occur, the current circulating on the neutral
may be higher than that of the phases.
WARNING: For three-pole circuit-breakers without external neutral, the Neutral protection setting must be Off,
otherwise the sensor presence error will be signalled (Error CS).
In these cases, connect T5-T6 to the sliding contacts, as shown in the wiring diagrams.
WARNING: Failure to comply with the setting limits of "I1" and "InN" may result in damage to the circuit-break-
er and consequent risks even for the operator.
WARNING: The protection setting is automatically 100% when the current value exceeds 15.5xIn on the neutral.
2.4.7.
Protection against instantaneous short-circuit "Iinst"
The purpose of this protection is to maintain the integrity of the circuit-breaker and installation in the case of particularly high
current requiring shorter reaction times than those guaranteed by the instantaneous short-circuit protection.
The protection cannot be disabled. It has a single fixed time protection curve and the threshold level is exclusively at the charge
of ABB personnel.
2.4.8.
Summary table of protections
Trip threshold
0.4 - 0.425 - 0.45 - 0.475 - 0.5 -
0.525 - 0.55 - 0.575 - 0.6 - 0.625 -
L
I1
0.65 - 0.675 - 0,7 - 0.725 - 0.75 -
(t=k/I
)
=
2
0.775 - 0.8 - 0.825 - 0.85 - 0.875 -
0.9 - 0.925 - 0.975 - 1 x In
S
I2
1 - 1.5 - 2 - 2.5 - 3 - 3.5 - 4 - 5 -
(t=k)
=
6 - 7 - 8 - 8.5 - 9 - 9.5 - 10 x In
S
I2
1 - 1.5 - 2 - 2.5 - 3 - 3.5 - 4 - 5 -
(t=k/I
)
=
6 - 7 - 8 - 8.5 - 9 - 9.5 - 10 x In
2
I
I3
1,5 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 -
(t=k)
=
10 - 11 - 12 - 13 - 14 - 15 x In
6,0xIn ≤ I
MCR
5
(t=k)
step 0,1xIn
I4
0,2 - 0,3 - 0,4 - 0,6 - 0,8 - 0,9 -
G
=
1 x In
(t=k)
I4
0,2 - 0,3 - 0,4 - 0,6 - 0,8 - 0,9 -
G
=
1 x In
(t=k/I
)
2
(1) The minimum value of this trip is 1s regardless of the type of curve
set (self-protection).
(2) These tolerances apply in the following conditions:
- Self-energized protection release in service conditions (no start-up)
with 2 or 3 supplied phases
and/or in presence of auxiliary supply. .
- operating temperature within the -25° ...70° range
- primary current values within the operating limits (see par. 1.2.7)
(3) The interval of time for which the protection is activated can be
selected via Ekip Connect, and is calculated from the moment the
CB closes.
B0431
Model
≤15xIn
B1751
Trip time
t1
3 - 12 - 24 - 36 -
=
48 - 72 - 108 -
144 s
(1)
@I
=3I1
f
Where I
> I2
f
t2
0.1 - 0.2 - 0.3 - 0.4 -
=
0.5 - 0.6 - 0.7 - 0.8 s
t2
0.1 - 0.2 - 0.3 - 0.4 -
=
0.5 - 0.6 - 0.7 - 0.8 s
@ 10 In
≤ 30 ms
@I
>I
f
5
≤ 30ms
(3)
Where I
> I4
f
t4
0.1 - 0.2 - 0.4 - 0.8 s
=
Minimum trip time
t4
0.1 - 0.2 - 0.4 - 0.8 s
=
For all cases not covered by the above hypotheses, the following tolerances apply:
Protection rip threshold
L
Release between 1,05 e 1,25 x I1
S
± 10%
I
± 15%
G
± 10%
Others
± 20%
Apparatus
Emax X1-Tmax T7-Tmax T8
Doc. No
Trip
threshold
tolerance
(2)
tolerance
Release
between
± 10% I
1.05 and 1.2
± 20% I
x I1
± 7% I
≤ 6
f
x In
The best of the two data:
± 10% o ± 40 ms
± 10% I
>6
f
x In
≤ 6
± 7% I
f
x In
± 15% I
± 10% I
>6
± 20% I
f
x In
± 10%
±10%
The best of the two data:
± 7%
± 10% o ± 40 ms
± 7%
± 15%
Trip time
± 20%
± 20%
≤ 60ms
± 20%
1SDH000587R0002
Trip
time
(2)
≤ 6 x In
f
> 6 x In
f
≤ 6 x In
f
> 6 x In
f
Scale
Page No
13/66
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