EKF VA-99M EKF - Page 10

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IR (A) - Set point of overload protection tripping, A. Setting values
for each dimension are shown in Table 4.
Kt1 (s) - Time delay of overload current tripping for current 2Ir1, s.
Possible setting is 12-100 s.
Isd (xIR) – Set point of short-circuit current protection tripping is set relative to
the preset Ir1. The switch has 10 positions (2-12xIr1).
Ktsd (s) - Time delay of short-circuit current tripping, s. Possible setting is
0.06-0.3s. The function is available when any time t2 is set except off.
Ii (xIR) - Set point of instantaneous short-circuit current protection is set
relative to the preset Ir1. The switch has 10 positions (4-14xIr1).
IRO (xIR) – Set point of overload alarm current is set relative to the preset Ir1,
it does not trip the circuit breaker. The switch has 8 positions (0.7-1xIr1).
Description of the electronic trip unit for VA-99M
0.65
0.7
0.8
0.9
1.0
1.0
0.4
0.5
0.55
0.6
IR (A) Kt1 KtsdIsd (
+
IR ) Ii (
+
IR ) IRO (
+
IR )
OFF
12
60
100
150
5
6
7
8
10
12
2
2.5
3
4
9
10
11
12
14
OFF
4
6
7
8
.85
.9
.95
1
1
1
1
.7
.75
0.8
OFF
.06
0.1
0.2
0.3
Table 5.1 - Kt1 Settings
Reverse delay
time (s)
(2Ir1)
2
I
2
t1
T=
(Isd>I>Ir1)
Kt1 (s)
Encoder settings
12 60
80
(100)
100
(150)
E.g.: 2Ir1
In≤250
(T) Tripping time
12 60 80 100
OFF
(without
protec-
tion)
E.g.: 4Ir1 3 15 20 25
E.g.: 2Ir1
In≥400
(T) Tripping time
12 60 100 150
E.g.: 4Ir1 3 15 25 37.5
Error ±20%