ABB REG670 - Page 1266

Table 969: IEC Inverse time characteristics for Voltage restrained time overcurrent protection
Function Range or value Accuracy
Operating characteristic:
( )
1
= ×
-
æ ö
ç ÷
ç ÷
è ø
P
A
t k
I
EQUATION1251-SMALL V1 EN
I = I
measured
/I
set
0.10 ≤ k ≤ 3.00 IEC 60255-151, ±5.0%
or ±40 ms whichever is
greater
IEC Normal Inverse A=0.14, P=0.02
IEC Very inverse A=13.5, P=1.0
IEC Inverse A=0.14, P=0.02
IEC Extremely inverse A=80.0, P=2.0
IEC Short time inverse A=0.05, P=0.04
IEC Long time inverse A=120, P=1.0
Table 970: Inverse time characteristics for overvoltage protection
Function Range or value Accuracy
Type A curve:
=
- >
>
æ ö
ç ÷
è ø
t
k
U U
U
EQUATION1436-SMALL V1 EN
U> = U
set
U = U
measured
k = (0.05-1.10) in
steps of 0.01
±5.0% or ±45 ms
whichever is greater
Type B curve:
2.0
480
32 0.5
=
⋅
− >
⋅ −
0.035+
>
 
 
 
t
k
U U
U
EQUATION1437-SMALL V2 EN
k = (0.05-1.10) in
steps of 0.01
Type C curve:
 
3.0
480
32 0.5
=
⋅
⋅ −
− >
0.03
5
+
>
 
 
t
k
U U
U
EQUATION1438-SMALL V2 EN
k = (0.05-1.10) in
steps of 0.01
Programmable curve:
×
= +
- >
× -
>
æ ö
ç ÷
è ø
P
k A
t D
U U
B C
U
EQUATION1439-SMALL V1 EN
k = (0.05-1.10) in
steps of 0.01
A = (0.005-200.000)
in steps of 0.001
B = (0.50-100.00) in
steps of 0.01
C = (0.0-1.0) in steps
of 0.1
D = (0.000-60.000) in
steps of 0.001
P = (0.000-3.000) in
steps of 0.001
Section 25 1MRK502052-UEN B
Inverse time characteristics
1260
Technical manual