ABB Relion 670 Series Technical Reference Manual page 720

Section 20
Inverse time characteristics
714
Table 487: Inverse time characteristics for undervoltage protection
Function
Type A curve:
k
=
t
æ ö
< -
U U
ç ÷
è ø
<
U
EQUATION1431-SMALL V1 EN
U< = U
set
U = UV
measured
Type B curve:
×
k 480
=
t
2.0
æ ö
< -
U U
ç ÷
× -
32 0.5
è ø
<
U
EQUATION1432-SMALL V1 EN
U< = U
set
U = U
measured
Programmable curve:
é ù
ê ú
×
k A
ê ú
= +
t
ê ú
P
æ ö
< -
U U
ê ú
ç × - ÷
B C
ë è ø û
<
U
EQUATION1433-SMALL V1 EN
U< = U
set
U = U
measured
Range or value
k = (0.05-1.10) in
steps of 0.01 unless
otherwise stated
k = (0.05-1.10) in
steps of 0.01 unless
otherwise stated
+
0.055
k = (0.05-1.10) in
steps of 0.01 unless
otherwise stated
A = (0.005-200.000)
in steps of 0.001
D
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
1MRK 505 208-UEN B
Accuracy
Class 5 +40 ms
Technical reference manual