ABB RET670 - Inverse Time Characteristics for Undervoltage Protection

Table 121. Inverse time characteristics for undervoltage protection
Function Range or value Accuracy
Type A curve:
=
< -
<
æ ö
ç ÷
è ø
k
t
U U
U
EQUATION1431-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
0.055
32 0.5
×
= +
< -
× -
<
æ ö
ç ÷
è ø
k
t
U U
U
EQUATION1432-SMALL V1 EN
U< = U
set
U = U
measured
k = (0.05-1.10) in steps of 0.01
Programmable curve:
×
= +
< -
× -
<
é ù
ê ú
ê ú
ê ú
æ ö
ê ú
ç ÷
ëè ø û
P
k A
t D
U U
B C
U
EQUATION1433-SMALL V1 EN
U< = U
set
U = U
measured
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
Transformer protection RET670 2.0
1MRK 504 141-BEN C
Product version: 2.0
102 ABB