Basler Electric DGC-2020HD - Manual (Page 353)

9469300990 Rev B 343
Relay Equation
When the 46 function is used, the relay uses the K factor (i.e., 46 time dial setting), 46 minimum pickup
setting, and generator full-load current to create a constant Z (see Equation 13).
𝑍 = 46 𝑇𝑖𝑚𝑒 𝐷𝑖𝑎𝑙 �
𝐼
𝑁𝑜𝑚 𝑆𝑒𝑡𝑡𝑖𝑛𝑔
46 𝑃𝑖𝑐𝑘𝑢𝑝 𝑆𝑒𝑡𝑡𝑖𝑛𝑔�
2
Equation 13
The time to trip equation used in the relay is:
𝑇
𝑇
=
𝑍
𝑀 2
+ 0.028 𝑠𝑒𝑐𝑜𝑛𝑑𝑠
Equation 14
where:
𝑀 =
𝑀𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝐼
2
46 𝑃𝑖𝑐𝑘𝑢𝑝 𝑆𝑒𝑡𝑡𝑖𝑛𝑔
Equation 15
which, when M > 1, reduces to:
𝑇
𝑇
= 46 𝑇𝑖𝑚𝑒 𝐷𝑖𝑎𝑙 �
𝐼
𝑁𝑜𝑚 𝑆𝑒𝑡𝑡𝑖𝑛𝑔
𝐼
2
𝑀𝑒𝑎𝑠𝑢𝑟𝑒𝑑�
2
Equation 16
DGC-2020HD Time Curve Characteristics