Table 73. 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 = UV
measured
k = (0.05-1.10) in steps of 0.01
±5% +60 ms
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
Table 74. Inverse time characteristics for residual 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% +70 ms
Type B curve:
2.0
480
32
0.5
0.035
=
×
-
>
×
-
-
>
æ
ö
ç
÷
è
ø
t
k
U
U
U
EQUATION1437-SMALL V1 EN
k = (0.05-1.10) in steps of
0.01
Type C curve:
3.0
480
32
0.5
0.035
=
×
-
>
×
-
-
>
æ
ö
ç
÷
è
ø
t
k
U
U
U
EQUATION1438-SMALL V1 EN
k = (0.05-1.10) in steps of
0.01
Transformer protection RET650
1MRK 504 137-BEN B
Product version: 1.3
ABB
59
