ABB RET670 Product Manual page 88

Transformer protection RET670
Customized
Product version: 1.2
Inverse characteristic
Table 109. ANSI Inverse time characteristics
Function
Operating characteristic:
æ ö
A
ç ÷
= + ×
t B k
( )
ç ÷
P
è - ø
I 1
EQUATION1249-SMALL V1 EN
Reset characteristic:
t r
= ×
t k
( )
2
-
I 1
EQUATION1250-SMALL V1 EN
I = I /I
measured set
ANSI Extremely Inverse
ANSI Very inverse
ANSI Normal Inverse
ANSI Moderately Inverse
ANSI Long Time Extremely Inverse
ANSI Long Time Very Inverse
ANSI Long Time Inverse
88
Range or value
k = (0.05-999) in steps of 0.01
A=28.2, B=0.1217, P=2.0 , tr=29.1
A=19.61, B=0.491, P=2.0 , tr=21.6
A=0.0086, B=0.0185, P=0.02, tr=0.46
A=0.0515, B=0.1140, P=0.02, tr=4.85
A=64.07, B=0.250, P=2.0, tr=30
A=28.55, B=0.712, P=2.0, tr=13.46
A=0.086, B=0.185, P=0.02, tr=4.6
1MRK 504 117-BEN D
Accuracy
-
ANSI/IEEE C37.112, 5%
+ 40 ms
ABB