Overcurrent Elements
Page 3 of 7
20120723
Step 4
Determine the
Neutral Inst Overcurrent Trip Level
setting.
50NN21P = ________________
Set the 50N element to 50 percent of the maximum ground fault current. Obtain the maximum value from
a system fault study.
For this example, assume a 5,000 A ground fault current.
Step 5
Verify that the
Neutral Inst Overcurrent Trip Delay
(50NN1D) is set at minimum value of 0.50.
Step 6
Select
Group 1 > Set 1 > Winding 2 Elements
.
Figure 3 Phase Time-Overcurrent Element Settings
Step 7
Determine the
Winding 2 Phase Time Overcurrent Trip Level
setting.
51P2P = __________________
Set the phase time-overcurrent element to 150 percent of the continuous rated amperes.
Step 8
Set the
Winding 2 Phase TOC Curve Selection
to coordinate with the downstream time-overcurrent
protection.
51P2C = __________________
