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Electronic Theatre Controls Inc

Sensor CEM Displays Airflow Errors and May Flash Loads

  1. ETC has found that the airflow sensor used in the CEM is very sensitive, and can on occasion give false readings of lack of airflow.  The CEM Airflow Deflector (ETC P/N 7050A1059) should be installed.
  2. The filters in the rack are dirty and not allowing adequate airflow to the rack.  The filters should be cleaned, either with an air hose or tap water.
  3. The fan in the rack has stopped spinning and is no longer creating airflow in the rack.  Replace the fan.
  4. The fan relay in the CEM could be the problem.  This can be tested via the backdoor diagnostics airflow test.
  5. On Touring Racks, the fan is on the bottom of the rack.  DO NOT STORE THE FEEDER CABLES UNDER RACK.

Workaround / Fix

  1. Remove filters, clean, dry, and replace.
    Filters can be blown out, vacuumed, or washed out with water. If using water, make sure filter is completely dry before replacing into rack.
  2. Determine if the CEM or the fan is the problem, and obtain servicing on problem equipment.
  3. Install a CEM airflow deflector in the CEM to help direct airflow over the airflow sensor.  (Part number 7050A1059)