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1. Under Range. The meter is being asked to display a value which is more
--Ur--
negative than its limit of -199999
2. Over Range. The meter is being asked to display a value which is higher
--Or--
than its limit of 999999
These fault codes could be displayed because the signal is too negative, too
positive, or because there is a wiring error, or because the display's scaling
has been adjusted to give excessive sensitivity, or because there is a fault in
the display.
a. If you are connecting a 4-20mA signal to the display, please measure the
DC millivolt signal between terminals 2(-) and 3(+) Ideally, you will measure
132mV at 4mA and 660mV at 20mA.
If the voltage is much higher, there may be a problem with the 33 Ohm input
shunt resistor.
You can verify this as follows...
Remove the input signal and power connectors to the meter, and measure
the resistance between terminals 2 and 3. This should be 33 Ohms. If it is
more than this, the resistor has probably been overloaded and burned by
having a voltage connected across it. Please check your field wiring to en-
sure that no more than 30mA or 1V can be applied to the current input
terminals.
Sometimes excessive current can feed to the current input of the display if
your 2 wire 4-20mA transmitter is faulty or is wired incorrectly, because we
rely on the transmitter to regulate the loop current between 4 and 20mA. The
excitation power supply for the loop may have a much higher capacity than
20mA.
b. If the measurements above were satisfactory, the problem may be caused
by the scaling being too sensitive.
If you are happy to do so, it is a simple matter to reset the display's scaling to
the factory default conditions. Put the lockout switch off and press all 4
buttons together for around 3 seconds until the display shows "dEFS n".
Then press the UP button once so the display shows "dEFS Y". Now press
the OK button and the display will be reset to factory defaults.
If still no success, please return the display to us for the attention of our QA
Manager, with a report of what you found, for repair.
Error codes and fault finding
39
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