12.9
Date Code 20090730 Instruction Manual SEL-734 Meter
Testing and Troubleshooting
Testing Methods and Tools
The SEL-734 accepts subsequent TEST MODE commands when a TEST
mode session is already in progress, but only if command entry occurs at the
same port that issued the original command. Enter the TEST MODE OFF
command at any port to exit TEST mode.
Test Methods
Test the pickup and dropout of meter elements by using one of three methods:
target command indication, output contact closure, or sequential events
recorder (SER).
The examples below show the settings necessary to route the first KYZ
element KYZD1 to the output contacts and the SER. The KYZD1 element,
like many in the SEL-734, is controlled by enable settings and/or SEL
OGIC
®
control equations. To enable the KYZD1 element, set the EKYZ enable
setting to the following:
EKYZ = 1 (via the SET command)
Testing Via Front-Panel Indicators
Display the state of meter elements, inputs, and outputs by using the front-
panel or serial port TAR commands. Use this method to verify the pickup
settings of elements.
Access the front-panel TAR command from the front-panel ENTER pushbutton
menu. To display the state of the KYZD1 element on the front-panel display,
press the ENTER pushbutton, cursor to the
TAR option, and press ENTER. Press
the UP ARROW pushbutton until
TAR 12 displays on the top row of the LCD.
The bottom row of the LCD displays all elements asserted in Meter Word Row
12. The meter maps the state of the elements in Meter Word Row 12 on the
bottom row of LEDs. The KYZD1 element state is reflected on the left-most
digit. See Table 10.18 for the correspondence between the Meter Word bits
and the TAR command.
To view the KYZD1 element status from the serial port, issue the TAR
KYZD1 command. The meter will display the state of all elements in the
Meter Word row containing the KYZD1 element.
Review the TAR command descriptions in Section 10: Communications and
Section 11: Front-Panel Operation for further details on displaying element
status via the TA R commands.
Testing Via Front-Panel and Output Contacts
When comparing front-panel energy registers and the number of KYZ output
pulses, please follow the pulse schedule detailed in Table 12.3 to ensure
0.02 percent measurement accuracy per IEC 687: Output devices generally do
not produce homogeneous pulse sequences. Therefore, the manufacturer shall
state the necessary number of pulses to ensure a measure accuracy of at least
1/10 of the class of the meter at the different test points. Once the number of
pulses exceeds the value listed in Table 12.3, the difference between the front-
panel pulse outputs is negligible.
Courtesy of NationalSwitchgear.com
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