©2025 Copeland LP.
026-1803 R13 Supervisor I&O User Guide 9 - 19
Multiple Stage Support
Multiple Stage Support is activated based on a stage delay in
conjunction with the T-Stat Deadband parameter when
multiple heating or cooling stages are defined.
The Two Delay Parameters are the Following:
• Cool Stage Delay - The delay between cool stage
activations or deactivations. After a cool stage is
activated, the AHU waits an amount of time equal to the
Cool Stage Delay. If the temperature is still above the cool
setpoint (plus one-half the deadband) it activates the next
stage of cooling. Similarly, after a cool stage is
deactivated, the AHU waits until the Cool Stage Delay has
elapsed, and if the temperature is still below setpoint
(minus one-half the deadband) it deactivates the next
cool stage.
• Heat Stage Delay - The delay between heat stage
activations or deactivations. After a heat stage is
activated, the AHU waits an amount of time equal to the
Heat Stage Delay. If the temperature is still below the heat
setpoint (minus one-half the deadband) it activates the
next stage of heating. Similarly, after a stage is
deactivated, the AHU waits until the Heat Stage Delay has
elapsed, and if the temperature is still above setpoint
(plus one-half the deadband) it deactivates the next heat
stage.
9.13.6 Heat/Cool Lockout Based on
Outside Air Temperature
The heating and cooling functions can be disabled if the
outside air temperature is outside of a specified range.
Cooling can be configured for OAT lockout by setting the
“Cool Lockout En” parameter to Yes. When enabled, if the
outside air temperature falls below the value specified by
“COOL OAT LO, C”, all cooling functions are disabled. When
the outside air temperature rises above this setpoint, cooling
is enabled.
Heating can be configured for OAT lockout by setting the
“Heat Lockout En” parameter to Yes. When enabled, if the
outside air temperature rises above the value specified by
“HEAT OAT LOC”, all heating functions are disabled. When
the outside air temperature falls below this setpoint, heating is
enabled.
9.13.7 System Shutdown
If the SHUTDOWN input is turned ON, the application goes
into a shutdown mode that immediately turns off any heating
or cooling stages presently on. The heating and cooling
stages remain OFF as long as the SHUTDOWN input is ON.
9.13.8 Fan Control
The AHU application supports a single-speed indoor fan.
9.13.9 Fan Mode
The fan can be designated as Continuous, Auto, or Summer
On/Winter Auto. There are separate fan mode settings for
occupied heating, unoccupied heating, occupied cooling
and unoccupied cooling. When the fan mode is set to “Auto”,
the fan only turns on if there is an active stage of heating/
cooling or if economization is enabled. When the fan mode is
set to “Continuous”, the fan runs continuously in the selected
heating or cooling mode, regardless of whether any stages of
heating or cooling are currently active. When the fan mode is
set to “Sum ON/Win Auto”, the fan runs continuously during
the summer season, and runs in Auto mode during the winter
season.
9.13.10 Plenum Warmup/Purge
The application supports a plenum warmup/cooldown delay
on startup and a purge delay when turning off. There are
separate delays for both heating and cooling modes, and
these are only used when the fan is in Auto mode. The
warmup/cooldown delays allow the plenum to reach a target
temperature before turning on the fan to prevent undesirable
supply air from reaching the building occupants. The purge
delays are used to extract the remaining heat/cold from the
plenum after the heating/cooling has turned off.
9.13.11 Fan Proof Failure
When Fan Prf Fail En is enabled and a fan proof failure is
detected, heating and cooling loads are shut down until the
proof failure goes away or the fan proof alarm is reset or
cleared. If the fan is configured to shut down on a fan proof
failure, the system is restarted by setting the FAN FAIL RST
input to ON or clearing the fan proof failure from the advisory
log.
9.13.12 System Shutdown
If the SHUTDOWN input is turned ON, the application goes
into a shutdown mode that turns off the fan. The fan remains
OFF as long as the SHUTDOWN input is ON.
NOTE
NOTE: The variable speed fan support may be
incorporated into this application in a later phase
of the product.
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