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10.11
Date Code 20171006
Instruction Manual
SEL-400 Series Relays
Testing, Troubleshooting, and Maintenance
Test Methods
The operating time (t
p
) for a time dial (TD) equal to 1 for the U3 (Very Inverse)
Curve is:
Equation 10.2
In this example, use QuickSet to configure the relay. You must have a computer
that is communicating with the SEL-451 and running the QuickSet (see
Settings Changes in Initial Global Settings on page 3.20
). You also need a vari-
able current source for relay testing.
Step 1. Prepare to control the relay with QuickSet by establishing communi-
cation, checking passwords, and reading relay settings.
Step 2. Set the selectable operating quantity time-overcurrent element for
test operation.
a. Open the
Group 1 > Set 1> Relay Configuration > Time Over-
current
branch of the
Settings
tree view (see
b. Verify that enable setting E51S (Selectable Inverse-Time
Overcurrent Element) is set to 1, or greater.
c. In the
Time Overcurrent
dialog box, change setting
51S1O
Operating Quantity
to
3I0L
.
d. Change the remaining element configurations to match
t
p
TD • 0.0963
3.88
M
2
1
–
----------------
+
=
1 • 0.0963
3.88
1.5
2
1
–
-------------------
+
=
3.2 seconds
=
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