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Programming and Operation,
continued
39
After a few seconds the screen displays the test
result as seen below. This is a raw reading that
verifies the sensor decoder is working.
4. Click
OK
to return to the
Test of Sensor
Decoders
screen and use the
up
and
down
arrows
to choose another sensor decoder to test
and select
OK
.
5. Repeat
Step 4.
as necessary to test all the sensor
decoders or select ‘- ‘to return to the
Main Menu
.
Finding a short in the system
You can use the MDC2 Controller to help trace and
locate
shorts
in the lines.
1. Attach a clamp from a Clamp Amperemeter to
one of the communications wires connected to
either L1 or L2 terminals in the controller.
2. Turn on the controller and navigate to the
Test
menu.
3. Move the
indicating arrow
to
3. Short Finding
and select
OK
to reach the
Short Finding
screen. In
Short Finding Mode
, the MDC
changes the frequency of the line voltage from 1
to 50 Hertz (Hz).
4. Check that the Clamp Amperemeter reads the
current supplied by the controller. If the reading
is higher than you expected, you have either a
short
or an
overload
in the system.
Note:
If the
short
takes a high current, the MDC2
Controller automatically limits the current to a safe
value of 200 mA. When this happens, the controller
will go into the 50 Hz mode and a
Short Circuit
Warning
shows on the display. Please see
Sensing
a Short Circuit
on page 55.
5. To locate the
short
, “follow” the current from
the controller to the decoders in the field.
6. Watch the reading on the Clamp Amperemeter
closely. The reading disappears the moment you
pass the
short
.
7. Once you locate the
short
, press any button on
the controller to return to the
Test
menu.
*** Test of Sensor Decoders ***
01:38 PM
Sensor Decoder: SD1 50085
Got answer: 32
Use ‘ ’ to Cancel
–
Short Finding Mode
Summary of Contents for MDC2
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