Installation & Operation Manual - Model AVC5000
Contents of this Manual are Subject to Change Without Notification
Page 36
6.6.4.2.5
Configure Alarms
Because there can be up to 4-levels of user-defined control set points based on the DI states,
each available alarm must be configured to coincide with a corresponding control setpoint
based on the DI states. The AVC5000 has the following alarms and parameters available.
6.6.4.2.5.1
Face Velocity Alarms
(programmable Alarm delays are available)
-
Low Face Velocity Alarm
: Indicates when the measured face velocity is less than the low
velocity alarm threshold.
-
High Face Velocity Alarm
: Indicates when the measured face velocity is greater than the
high velocity alarm threshold.
-
Face Velocity Set Point Deviation Alarm:
Indicates when the measured face velocity
deviates from set point by more than the programmed value (% set point).
6.6.4.2.5.2 Volume Alarms
(programmable Alarm delays are available)
-
Low Volume Alarm
: Indicates when the measured airflow volume is less than the low
volume alarm threshold.
-
High Volume Alarm:
Indicates when the measured airflow volume is greater than the high
volume alarm threshold.
-
Volume Deviation Alarm:
Indicates when the measured airflow volume deviates from set
point by more than the programmed value (% set point)
6.6.4.2.5.3 Sash % Open Alarm
(programmable Alarm delays are available)
Indicates when the sash open area is greater than the programmed sash high % alarm threshold
6.6.4.2.5.4 Sash Sensor Fault Alarm
Provides an alarm if the vertical or horizontal sash sensor exceeds their normal range of
operation which occurs if a wire breaks or a sensor is damaged.
6.6.4.2.5.5 Actuator Fault Alarm
(programmable Alarm delays are available)
Indicates when the actuator feedback signal deviates from the control input signal by more
than the programmed value. The value can be programmed anywhere between 5% and 100%.
6.6.4.2.5.6 Face Velocity High Alarm Override
Enabling this feature will temporarily suspend the face velocity alarms from occurring when the
controller is actively controlling to the minimum airflow volume limit. All other alarms will
remain active during this time. When the sash is raised to the point where the minimum
volume limit is exceeded, the face velocity alarm functionality will return to normal.
Note: Reason for Using the Volume Limits
VAV fume hood control applications utilize volume limits to conserve energy and
maintain safe operating conditions. The maximum volume limit conserves energy by
limiting the airflow when the sash is opened above the sash stops. The maximum
volume limit is also used to ensure the exhaust volume does not exceed the system
capacity when multiple fume hoods that share a common exhaust system have their
sashes opened simultaneously. The minimum volume limit is selected to ensure the
fume hood continues to draw clean air from the room into the fume hood when the sash
is closed or nearly closed. This minimum volume limit is normally selected to provide
sufficient dilution of the fume hood exhaust to meet local safety and building code
requirements based on the application.
