10-32 Testing and Troubleshooting Date Code 20080110
SEL-387E Instruction Manual
SLP1 = slope 1 setting
SLP2 = slope 2 setting
IRS1 = intersection where SLP2 begins
IRT = restraint quantity at which the calculation is carried out
For example:
Slope 1 = 25 percent
Slope 2 = 60 percent
PCT2 = 20 percent
IRS1 = 3, and choose IRT = 6
()
⎟
⎠
⎞
⎜
⎝
⎛
−−−
⎟
⎠
⎞
⎜
⎝
⎛
= 6025
6
3
60200•
200
20
harmonic% = 15.75 percent
Note: The second and fourth harmonics are combined to form the restraint
quantity.
Over-/Undervoltage Elements
Purpose: Verify the operation of over- and undervoltage elements.
Verify the operation of overvoltage elements.
Step 1.
Connect a source of variable three-phase voltage to the relay as shown in Figure
10.5.
Step 2.
Purpose: Verify the expected phase overvoltage pickup setting.
Method: Execute the
SHOWSET
command via the relay front panel or serial port
and verify the setting (i.e.,
SHO 59P1P <Enter>
).
Step 3.
Purpose: Display the appropriate Relay Word bit on the front-panel LEDs.
Method: Execute the
TARGET
command (i.e.,
TAR F 59P1 <Enter>
). The
SEL-387E Relay now displays the state of the overvoltage elements on
the bottom row of front-panel LEDs.
Step 4.
Purpose: Apply balanced three-phase voltage below the setting and raise one phase
voltage until the appropriate LED illuminates.
Method: Apply balanced three-phase voltages as shown in
Figure 10.5, adjusted to
a value below the
59P1P
setting. Raise one phase voltage until the
59P1
LED illuminates. The voltage should equal the
59P1P
setting
±2 V
and
±5% of setting. Repeat the test for the other two phases.
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