Table 74. Inverse time characteristics for residual overvoltage protection
Function
Range or value
Accuracy
Type A curve:
=
-
æ
ö
ç
÷
è
ø
t
td
V
VPickup
VPickup
EQUATION1661 V1 EN
V = V
measured
td = (0.05-1.10) in
steps of 0.01
Class 5 +40 ms
Type B curve:
=
×
-
×
-
-
æ
ö
ç
÷
è
ø
2.0
480
32
0.5
0.035
t
td
V
VPickup
VPickup
EQUATION1662 V1 EN
td = (0.05-1.10) in
steps of 0.01
Type C curve:
=
×
-
×
-
-
æ
ö
ç
÷
è
ø
3.0
480
32
0.5
0.035
t
td
V
VPickup
VPickup
EQUATION1663 V1 EN
td = (0.05-1.10) in
steps of 0.01
Breaker protection REQ650 ANSI
1MRK 505 269-BUS -
Product version: 1.1
Issued: April 2011
84
ABB