Orion System HB Controller - Manual (Page 6)

Sequence of Operations
HB Controller Technical Guide 6
Controller Sequence of Operations
SAT Lockout Modes
Note: The SAT Lockout Modes only apply if a Supply Air
Temperature Sensor is installed on the HB unit.
SAT High Temperature Limit Cut Off Mode
During the Heating Mode, if the Supply Air Temperature rises above
the Supply Air High Temperature Limit Cut Off (150° F), the Heating
will stage off, but the main Supply Fan will remain on in Low-Speed
operation. If this occurs, the Supply Air Temperature must fall below
80° F in order for the Heating to stage back on. If this condition oc-
curs 2 times consecutively during a Heating call, the HB Controller
will lockout in Supply Air High Temperature Limit Cut Off. To restore
normal operation, either remove the call for Heating or cycle power to
the HB Controller.
SAT Low Temperature Limit Cut Off Mode
During the Heating Mode, if the Supply Air Temperature falls below
the Supply Air Low Temperature Limit Cut Off (40° F), the Outdoor
Air Damper will close. If the Supply Air Temperature is still too cold
and remains there for 15 minutes, the Heating and the Supply Fan will
be turned off and locked out. This condition can only happen once, and
then the HB Controller will lockout in Supply Air Low Temperature
Limit Cut Off. To restore normal operation, either remove the call for
Heating or cycle power to the HB Controller.
Exhaust Fan Control
The Exhaust Fan is energized via the Auxiliary Relay. The Exhaust Fan
has two Economizer Position Activation points based on the Low- and
High-Speed Supply Fan condition. The air balancing contractor should
determine these settings for proper Building Pressure Control.
HB Processor Board
When the HB Controller has the optional HB Processor board installed,
a Space Temperature Sensor can be connected to it for HVAC Mode
Control. When the Space Temperature Sensor is used, the Push-Button
Override and Slide Adjust options are also available. Occupied and
Unoccupied Modes are available through week scheduling, force sched-
ule, and a broadcast schedule. The HB Processor board also provides
communication with other HB controllers. Up to 60 other controllers
can be connected together via the RS-485 loop.
Space Temperature Control Sequence
When the Space Temperature Sensor is confi gured for control, Cooling
and Heating setpoints are used to activate the HVAC Modes of operation.
An HVAC Mode Deadband setpoint is used to determine the temperature
at which the Cooling and Heating Modes are activated above or below the
setpoints. Once in the Cooling Mode, the Space Temperature must drop
below the Cooling setpoint minus the deadband to enter the Vent Mode.
The same is true for the Heating mode; the Space Temperature must rise
above the Heating setpoint plus the deadband to enter the Vent Mode.
An additional Cooling Stage is activated for each 1° F rise of the Space
Temperature above the Cooling Setpoint up to the maximum number of
Cooling Stages available. In like manner, an additional Heating Stage is
activated for each 1° F drop of the Space Temperature below the Heating
Setpoint up to the maximum number of Heating Stages available.
When the Space Temperature rises above the Cooling setpoint plus the
deadband, the HB Controller enters the Cooling Mode, and Cooling Stage
1 is activated. Cooling Stage 2 is activated if the Space Temperature rises
by another 1° F above the Cooling setpoint. Cooling Stage 2 deactivates
when the Space Temperature drops below the Cooling setpoint. Cool-
ing Stage 1 deactivates when the Space Temperature drops below the
Cooling setpoint minus the deadband.
When the Space Temperature drops below the Heating setpoint minus
the deadband, the HB Controller enters the Heating Mode, and Heating
Stage 1 is activated. Heating Stage 2 is activated if the Space Temperature
drops by 1° F. Heating Stage 3 is activated if the Space Temperature
drops by another 1° F below the Heating setpoint. Heating Stage 3 and
Heating Stage 2 both deactivate when the Space Temperature rises
above the Heating setpoint. Heating Stage 1 deactivates when the Space
Temperature rises above the Heating setpoint plus the deadband.
The Slide Adjust feature on the Space Temperature Sensors that are
equipped with this option allows the user to change the Heating and
Cooling setpoints up or down by the Slide Adjust setpoint value. If 3°
F is entered as the Slide Adjust setpoint, when the slider is all the way
up, the Heating and Cooling setpoints will be raised by 3° F. When the
slider is all the way down, the Heating and Cooling setpoints will be
lowered by 3° F. The Override Button feature on Space Temperature
sensors that are equipped with this option allows the user to force the
HB Controller into the Occupied Mode. The time the controller is in
Occupied Mode is determined by the Override Time Setpoint. Once
this time is expired, the HB Controller will follow its normal schedule.
A momentary push of the Override Button will activate the Override.
Once in the Override Mode, pushing down and holding the Override
Button for 5 seconds will deactivate the Override Mode.