©2025 Copeland LP.
026-1803 R13 Supervisor I&O User Guide 9 - 21
9.13.14 Determine the Analog Damper
Position
The analog damper position is determined by using a PID
loop. The output is based on the mixed air temperature
compared to the occupied or unoccupied mixed air setpoint
(“Occ CL Mix Temp” or “Unoc CL Mix Tmp”). The output is
limited to the occupied or unoccupied minimum damper
position. If the economization is inactive, the analog damper
is set to the occupied or unoccupied minimum damper
position, based on the current occupancy state. If the
economization is active, the output from the Economizer PID
loop is written to the analog damper output.
9.13.15 Determine the Digital Damper
Position
The digital damper output turns ON when economization is
active.
9.13.16 Heat Pump Control
If any heat pump stages are defined, they activate in
parallel with the first cooling and heating stages defined. For
example, if one heat pump stage and one heat stage are
defined, when a call for heat occurs, the heat pump stage is
considered stage one and it turns on along with the heat
stage (HEAT STAGE 1). If a second stage of heat is required,
two heat stages should be defined. Likewise, for cooling, if
one heat pump stage and one standard cooling stage are
defined, and a call for cooling occurs, the heat pump stage is
considered cool stage one and it turns on along with the
COOL STAGE 1 output. If a second stage of cooling is
required (not a heat pump stage), two cool stages should be
defined.
9.13.17 Reversing Valve
The reversing valve must be identified as either a heating or
cooling reversing valve by setting the “Reversing Valve”
parameter. When the reversing valve is set to cooling, the
reversing valve turns on when a call for cooling is active and
turns off when a call for heating is active. Likewise, when the
reversing valve is set to heating, the reversing valve turns on
when a call for heating is active and turns off when a call for
cooling is active. Once the call for heating or cooling is no
longer active, the reversing valve remains in its last known
state. When the AHU application is reset, the reversing valve
output initializes the OFF state.
9.13.18 Compressor Output
When either a call for heating or cooling is active, the
compressor output for the called stage turns on. When the
heating or cooling call is no longer active, the compressor
turns off.
Control Temperature
A control temperature advisory occurs after a user-specified
time delay for both high and low temperature conditions. This
advisory must have associated parameters to allow the user
to specify the high and low advisory value and the delay, and
must be separate setpoints for occupied and unoccupied
mode.
Supply Fan Proof Failure
A supply fan proof failure advisory is generated when the
AHU is calling for the supply fan to be ON and the fan status
input indicates the fan is not operating. This advisory should
have an associated parameter to allow the user to enable or
disable the advisory and a parameter to specify the time delay
before the advisory is activated.
9.13.19 Curtailment
To set up curtailment in the system software, the user must
designate which specific heating and cooling stages is
subject to curtailment. When the power company sends a
curtail command (for example, the value of the curtailment
device switches to “CLOSED”), all stages that are set up to be
curtailed is shut off and locked out.
NOTE
NOTE: Fan control is not directly affected by a
call for curtailment.
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