ABB RET670 Product Manual page 82

Transformer protection RET670 ANSI
Pre-configured
Product version: 1.2
Table 83. Inverse time characteristics for residual overvoltage protection
Function
Type A curve:
td
=
t
æ ö
-
V VPickup
ç ÷
è ø
VPickup
EQUATION1661 V1 EN
V = V
measured
Type B curve:
×
td 480
=
t
æ ö
-
V VPickup
ç × - ÷
32 0.5
è ø
VPickup
EQUATION1662 V1 EN
Type C curve:
×
td 480
=
t
æ ö
-
V VPickup
× -
ç ÷
32 0.5
è ø
VPickup
EQUATION1663 V1 EN
Programmable curve:
×
td A
=
t
P
æ ö
-
V VPickup
× -
ç ÷
B C
è ø
VPickup
EQUATION1664 V1 EN
82
Range or value
td = (0.05-1.10) in steps
of 0.01
td = (0.05-1.10) in steps
of 0.01
2.0
-
0.035
td = (0.05-1.10) in steps
of 0.01
3.0
-
0.035
td = (0.05-1.10) in steps
of 0.01
A = (0.005-200.000) in
+
D
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
1MRK 504 118-BUS A
Accuracy
Class 5 +40 ms
ABB