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Additional Functions
The WLTS has two additional functions to assist in testing and
commissioning: activating the trip unit for setting parameters
and testing the metering display.
Activation the trip unit
To activate the trip unit, press the "N" and "G" buttons
simultaneously.
The trip unit will remain activated until another button on the
handheld test device is depressed.
With this function, the "T.U.-Error"-LED can be checked if the
status test indicates that the trip unit must be replaced.
Activating the trip unit can allow additional diagnostic steps
to be performed.
This function activates the ETU and display only and does not
power the metering module or any connected CubicleBUS
modules.
Testing the measured value display
This function applies signals to the trip unit inputs which
simulate load currents in each of the phases for 30s. The
simulated load current is displayed as a single-phase current
on the display of the trip unit, and the measured value of the
current is also transmitted via the communication interface
to the connected
CubicleBUS
Modbus / PROFIBUS-DP networks.
Currents will be displayed on the trip unit only if the trip unit
is equipped with an integrated display (WLETU745 with
WLLCD748, WLETU748 with WLLCD748, WLETU776). Current
values will be available to be communicated when a
communication interface is installed.
1.
Connect 24 V dc to power the trip unit.
2.
Press the [I] and [N] buttons simultaneously
The simulated load current will be present on the first phase
for 30 seconds before switching to the next phase. The cycle
runs in the order L1, L2, L3, N, G). The test cycle is completed
when signals for all phases have been output.
modules and the connected
When a trip unit with the MeteringPLUS option (WLMETERP)
is tested without applying 24V dc, no simulated values will
appear on the display. In order to see and communicate the
simulated load currents, 24V dc must be present and power
up the trip unit and communications module.
Sample Test Report
See the following page for a sample test report.
Technical Support
For technical support, please contact the Technical Support
Hotline at 1- 800-333-7421, or submit a request through
Online Support Request:
http://support.automation.siemens.com/US
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