General
All CD-12 units are factory calibrated and 100% tested for proper operation. During normal operation the green status indicator LED
light will be on steady, the fan & alarm relay will be in standby mode and the 4-20 mA output will be at 4mA (in clean air). The unit also
performs a regular automatic self-test during normal operation. If the unit detects an improper voltage or inoperable component, it will
default into Error mode. In this error mode, the Alarm relay will be activated, the 4-20 mA current loop will go to 24 mA, the unit will
display the error code, the green status indicator LED light will flash and the buzzer will chirp intermittently. The Fan relay will also
engage if the Trouble Fan Setting Option is set to "ON".
Operation Test
Check that the green CD-12 status indicator LED light is illuminated continuously. If not, do not proceed with the tests. If the unit is in
error mode contact your local representative or Macurco technical service representative for information on resolving the problem.
1. Remove the single screw in the middle of the front cover of the CD-12.
2. Remove the front cover.
3. Observe the LED light on the front of the CD-12.
4. If the light is solid green proceed to step 6.
5. If the green status indicator LED light is off or flashing, refer to the General section above.
6. Locate the switch labeled ENTER/TEST on the left side of the printed circuit board. Press the Test switch once.
7. The CD-12 will step through a cycle test:
a. The display progresses through the BUZ (Buzzer Test), Art (alarm relay test), Frt (fan relay test) then 42t (4-20 mA output
test). Make sure that the settings are "on" or not disabled "diS".
b. During the first 10 seconds of the test cycle, the display will show BUZ and set off the audible buzzer
c. The alarm relay will be closed, so any devices connected to that relay will be tested.
d. The Fan relay will be activated for the next 1 minute of the test, so if the fan circuits are wired in the normal manner, the fan
should run.
e. The 4-20mA output will then ramp up from 4 to 16 mA over the next 130 seconds of the test, so if the circuit is wired in the
normal manner, the control panel or building automation system should respond.
f. At the end of the test cycle, the light will turn green and be on steady (Normal Operation), the fan & alarm relay will be in
standby mode and the 4-20 mA output will return to 4 mA (in clean air).
8. When testing is completed reassemble the unit or units.
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