Programming Guide

VAV-SVP01A-EN 85
Troubleshooting
Diagnostic Table
Ta ble 16 , p . 85 shows the VAV VV550/551 Controller diagnostics.
Table 16. Controller diagnostics
Diagnostic Air valve Fan Reheat
Invalid unit configuration
(a)
0 VDC 0 VDC 0 VDC
Controller failure Closed Off Off
Discharge air temperature failure (space temperature control) Normal Normal Normal
Discharge air temperature failure (ventilation flow control without
reheat)
Normal Don't care Don't care
Discharge air temperature failure (ventilation flow control with
reheat)
Closed Don't care Off
Discharge air temperature failure (flow tracking control) Normal Don't care Don't care
Low airflow (space temperature control) Normal Normal Local electric heat is Off;
local hydronic and all remote
heat is normal
Low airflow (ventilation flow control) Normal Don't care Local electric heat is Off;
local hydronic is normal;
remote is Don't care
Primary air temperature failure (space temperature control) Normal Normal Local electric heat is Off
(b)
;
local hydronic and all remote
heat is normal
Primary air temperature failure (ventilation flow control) Normal Don't care Normal
Primary air temperature failure (flow tracking control) Normal Don't care Don't care
Space temperature fail (space temperature control)
(c)
Occupied: cool minimum
flow setpoint Unoccupied:
closed
Series fan enabled;
parallel fan Off
Off
Space temperature fail (ventilation flow control)
(c)
Normal Don't care Normal
Space temperature fail (flow tracking control)
(c)
Normal Don't care Don't care
Local setpoint failure Normal Normal Normal
Flow sensor failure or flow sensor calibration failure (space
temperature control)
Normal pressure
dependent control
Normal Normal
Flow sensor failure or flow sensor calibration failure (ventilation flow
control)
Normal pressure
dependent control
Don't care Normal
Flow sensor failure or flow sensor calibration failure (flow tracking
control)
If the configured airflow
tracking offset is positive,
configure maximum
airflow. If the configured
airflow tracking offset is
negative, configure
minimum airflow
Don't care Don't care
Freeze protection active (ventilation flow control) Closed Off Off
Thumbwheel in */** position (single star position) Minimum airflow Normal Normal
Thumbwheel in */** position (double star position) Maximum airflow Normal Normal
Normal Normal Normal Normal
(a) When the unit configuration is invalid, all outputs are de-energized (0 VDC) so that they return to their normal state.
(b) If system mode is heat or auto with a warm or hot primary air temperature.
(c) When a temperature sensor fails after being valid, the controller generates a diagnostic to indicate the sensor loss condition. The controller automatically
clears the diagnostic once a valid sensor temperature value is present (non-latching diagnostic).