Carrier Touch Pilot - Cooling and Heating Operation; Control Interlock and Setpoint Logic; Active Setpoint Selection Details

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7.3 - Cooling / Heating
The Touch Pilot control can manage the whole range of
operations ensuring the correct functioning of the air-
conditioning unit. 61XWHZE heat pumps can operate either
in Cooling or Heating.
The unit operation is based on the following parameters:
• Unit On/Off status: This parameter indicates whether
the unit is shut down (not authorised to start) or in
operation (authorised to start).
• Control type: Indicates whether the unit operates in
Local, Remote or Network mode.
• Heating/Cooling selection in Local mode: The operating
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• Heat/Cool switch status in Remote mode: These contacts

• Heat/Cool selection in Network mode: The network
command [HC_SEL] permits heating/cooling control if
the unit is in Network operating mode.
Status Control
type
Heat/Cool
in Local
Heat/Cool
in Remote
Heat/Cool
in Network
Current
mode
o - - - - -
on local cool - - cooling
on local heat - - heating
on local - on_cool - cooling
on local - on_heat - heating
on remote - on_cool - cooling
on remote - on_heat - heating
on network - - cool cooling
on network - - heat heating
7.4 - Control interlock contact
This contact checks the status of a loop (customer safety
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delay at start-up has expired. This open contact leads to an
alarm shut-down, if the unit is running (alarm 10028).
7.5 - Control point
The control point represents the water temperature that the
unit must produce. It enables to decrease the required
capacity depending on the unit load operating conditions.
The heat exchanger entering water temperature is controlled


Control point = Active setpoint + Reset
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     
instead of any other setpoint calculation only when the unit
is in the Network operating type.
7.5.1 - Active setpoint
Two setpoints can be selected when the unit is in Heating
mode, and three setpoints can be selected when the unit is
in Cooling mode. The first cooling/heating setpoint is
normally used during occupied periods and the second
cooling/heating setpoint is used during unoccupied periods,
whereas the third cooling setpoint is used for ice storage (ice

Setpoint 1 Setpoint 2 Setpoint 3
Cooling Occupied Unoccupied Ice storage cooling setpoint
Heating Occupied Unoccupied -
Depending on the current operation type (local/remote/
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Main menu (Heat/Cool Select, GENUNIT) in Local mode,

section 3.8), with network commands in Network mode
(SP_SEL; CCN or BACnet) or automatically with the
setpoint time schedule (schedule 2).
The following table summarises the possible setpoint selections
based on the control type (local, remote, network) and the
following parameters:
• Local parameters:
- Heating/Cooling operating mode
(hc_sel, GENUNIT).
- Setpoint selection (sp_sel, GENUNIT).
• Remote setpoint contacts:
 
(GEN_CONF, Ice_cnfg must be set to “yes”).
- Ice done contact from EMM (SIOB EMM board,
DI4_ICE_SW, by default set to “closed”).
- Dual setpoint switch status (spt_sw).
• Network settings:
- Schedule 2 status for setpoint selection
(GENUNIT, SP_OCC set to “yes” or “no”).
Local operating type
Parameter status
Active
setpoint
Mode sp_sel Ice_cnfg Ice_done spt_sw sp_occ
cool sp-1 - * * - cooling stp 1
cool sp-2 no * * - cooling stp 2
cool sp-2 yes closed * - cooling stp 2
cool sp-2 yes open * - ice stp
cool auto - * * occupied cooling stp 1
cool auto no * * unoccupied cooling stp 2
cool auto yes closed * unoccupied cooling stp 2
cool auto yes open * unoccupied ice stp
heat sp-1 - * * - heating stp 1
heat sp-2 - * * - heating stp 2
heat auto - * * occupied heating stp 1
heat auto - * * unoccupied heating stp 2
Remote operating type
Parameter status
Active
setpoint
Mode sp_sel Ice_cnfg Ice_done spt_sw sp_occ
cool - - * open - cooling stp 1
cool - no * close - cooling stp 2
cool - yes closed close - cooling stp 2
cool - yes open close - ice stp
heat - - * open - heating stp 1
heat - - * close - heating stp 2
Network operating type
Parameter status
Active
setpoint
Mode sp_sel Ice_cnfg Ice_done spt_sw sp_occ
cool - - * * occupied cooling stp 1
cool - - * * unoccupied cooling stp 2
heat - - * * occupied heating stp 1
heat - - * * unoccupied heating stp 2
(*): any conguration (-): default conguration
NOTE: Ice storage conguration [Ice_cnfg] and ice done
contact [Ice_done] apply only to units with the optional
energy management module.