AH - A 6
Air Handler
Continuous Fan
When only the G is energized, the control will energize
the blower for fan only operation. When the G input
turns off, the control turns off the blower immediately.
Cooling Operation
• When the air handler receives Y1 or Y1 & Y2
demands, the 1st or 2nd stage blower will be selected
depending on the Y1 & Y2 input combinations. The
number of cooling stages can be selected via the User
Interface. The air handler is shipped for single stage
operation.
Heating Operation
• The Air Handler control will operate blower for Heat
Pump stages (Mechanical Heating) the same as in
cooling mode. (Reference table 2 above).
• If W1, W2 or W3 (without Y1, Y2 or G) signals are
present, the control will turn on the blower even if the
G signal is not present. The control will energize the
blower in the heating speed.
• There is no blower On or Off Delays in Electric Heat
mode; the Cooling Off Delay only applies after the Heat
Pump (Mechanical Heat) turns off.
• If more than one stage of Electric Heat demand is
called, the Heat calls, W1, W2 and W3 will be
energized at least 0.5 seconds apart.
24V Mode
Heat Pump & Electric Heat Applications
(Communicating Heat Pump)
When the request for electric and mechanical heat is
received, the AHC will energize the blower at auxiliary
heat airflow and turn on the electric heat contactors.
The number of heating contactors (stages of electric
heat installed and available) is determined by the
Comfort Control. If a blower request for a higher airflow
is received, the AHC will energize the blower at the
higher airflow. When the request to terminate electric
heat is received, the AHC will turn off the corresponding
heater outputs. If the mechanical heat demand
remains, the AHC will keep blower energized at
mechanical heat airflow. When the request to terminate
mechanical heat is received, the AHC will de-energize
the blower once any user selected fan-off delays have
expired.
(Non-communicating Heat Pump)
Operation of the AHC in with a non-communicating
Heat Pump is not allowed.
• When only one stage of Cooling is selected, the
indoor blower speed will default to Cooling HI fan speed.
• When two stages of Cooling are selected, the 1st
stage CFM can be selected via the User Interface
Assembly. In addition, the control will ignore Y2 when
Y1 is not present.
• If one stage of Cooling is selected, Y2 input will be
ignored by the air handler control.
• The Cool-On-Delay (selectable) will begin when both
Y1 & G are present. When the Y1 & G inputs are
removed, the blower will turn off after the Cool-Off-
Delay (selectable) has timed out.
Note: The O input must be present for cooling mode
to allow blower speed changes for dehumidification,
i.e. Fan Pre-Run and Short-Run.
Blower Operation vs. Y1 & Y2 Inputs - A/C &
Heat Pumps
To Next Page
Loading...
