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11.2.
Remote Unit
The size of the plant may force you to place the instrument in a location far from the photovoltaic panels (for example,
an integrated plant on the roof with no possibility of making the electrical connections on the same level as the modules
or strings).
The UT925 remote unit (optional) can be installed next to the photovoltaic panels, thereby making it possible to transmit
the radiation, ambient temperature, and panel temperature measurements to the instrument in REAL TIME (using the
Bluetooth kit). This will make your testing very simple and accurate, and also let you view and store the measurements.
How to make measurements using the remote unit:
-
Place the remote unit next to the panels.
-
Use the included RS232 cable to connect the module or environment temperature probe and the parallel
pyranometer to the Bluetooth adapter.
-
Switch the remote unit ON (green LED ON). The green power LED of the Bluetooth adapter will light (if not,
set the selector on its side to "PoRI").
The remote unit now is ready to transmit measurements to the I-V TRACER 935 instrument.
How to program the I-V TRACER 935 instrument for use with the remote unit:
-
Turn the instrument On and open the "System" menu.
-
Choose the Remote Unit - Bluetooth Adapter option.
-
In the Bluetooth Address (MAC) option, enter the MAC number marked on the BLUETOOTH-RS232 adapter
connected to the remote unit.
-
Click on "Apply" to confirm.
-
Insert the USB-BLUETOOTH adapter into the USB port.
The instrument is now ready to receive measurements from the remote unit.
The LED on the USB-BLUETOOTH adapter will light only when measurements are activated from the "MODULE"
or "STRING" menu.
11.3.
Module or String
The measurement functions are as follows:
Module: to measure a single panel, select the "Module" icon in the main menu,
String: to measure a string of panels, select the "String" icon in the main menu,
Main menu
Selecting the Module or String icon in the main menu displays the connection diagram on the screen; pressing "Continue"
displays the graph. This is how the choice of measurement of a single panel or of a string of panels is activated (the type
of measurement selected is displayed at the top centre of the screen). Independently of the selection made, the control
buttons under the graph let you control the measurements as described below:
• The maximum voltage between the inputs is 1000VDC. Do not measure voltage exceeding the limits in this manual.
• The maximum current the instrument tolerates is 10A DC. Do not carry out tests on FV module strings connected in
parallel.
• Never test FV modules or strings connected to the DC/AC converter.