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The functional testing of AHU with FDD controls shall be in accordance with the following steps:
Step 1: Sensor drift/failure:
  1. Disconnect outside air temperature sensor from unit controller.
  2. Verify that the FDD system reports a fault.
  3. Connect OAT sensor to the unit controller.
  4. Verify that FDD indicates normal system operation.
Step 2: Damper/actuator fault:
  1. From the control system workstation, command the mixing box dampers to full open (100 percent outdoor air).
  2. Disconnect power to the actuator and verify that a fault is reported at the control workstation.
  3. Reconnect power to the actuator and command the mixing box dampers to full open.
  4. Verify that the control system does not report a fault.
  5. From the control system workstation, command the mixing box dampers to a full-closed position (0 percent outdoor air).
  6. Disconnect power to the actuator and verify that a fault is reported at the control workstation.
  7. Reconnect power to the actuator and command the dampers closed.
  8. Verify that the control system does not report a fault during normal operation.
Step 3: Valve/actuator fault:
  1. From the control system workstation, command the heating and cooling coil valves to full open or closed, then disconnect power to the actuator and verify that a fault is reported at the control workstation.
Step 4: Inappropriate simultaneous heating, mechanical cooling, and economizing or all functions:
  1. From the control system workstation, override the heating coil valve and verify that a fault is reported at the control workstation.
  2. From the control system workstation, override the cooling coil valve and verify that a fault is reported at the control workstation.
  3. From the control system workstation, override the mixing box dampers and verify that a fault is reported at the control workstation.

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