ABB RET670 Product Manual page 86

Transformer protection RET670
Pre-configured
Product version: 1.1
Table 91. RI and RD type inverse time characteristics
Function
RI type inverse characteristic
1
= ×
t k
0.236
-
0.339
I
EQUATION1137-SMALL V1 EN
I = I /I
measured set
RD type logarithmic inverse
characteristic
æ ö
I
- ×
ç ÷
= 5.8 1.35 In
t
è ø
k
EQUATION1138-SMALL V1 EN
I = I /I
measured set
86
Range or value
k = (0.05-999) in steps of 0.01
k = (0.05-999) in steps of 0.01
1MRK 504 091-BEN B
Issued: June 2010
Accuracy
IEC 60255-3, class 5
+ 40 ms
IEC 60255-3, class 5
+ 40 ms
ABB