Heating/Cooling/Standby; Heating/Cooling Selection - Carrier SmartView Manual

6 - STANDARD CONTROL OPERATIONS AND OPTIONS

6.2 - Heating/Cooling/Standby

The control determines the heat/cool state of the unit. Chillers
fitted with a boiler may operate in cooling or heating mode. Without
a boiler, the unit remains in Cooling mode. Heat pumps may
operate in cooling or heating mode.
When the chiller is in Heating mode, the control utilises the boiler
to satisfy the heating demand. For heat pumps, the boiler is used
when mechanical heating is impossible or insufficient. Additionally,
when the outside air temperature is very low, electric heaters can
be used as a form of supplemental heating.
When Cooling mode is selected, the unit will operate in the
Cooling mode and, as a result, the boiler or electric heating will
not be activated.
If the unit is in Standby mode, it does not cool or heat and
compressors are stopped. The pump is running with no mechanical
cooling or heating unless configured otherwise. The pump may
be stopped depending on pumps configuration (PUMPCONF –
Pump Configuration).
HEATING STANDBY
Heating
threshold
Figure 4: Heating/Cooling changeover for heat
pumps and chillers fitted with a boiler
Operating mode control
The operating mode, i.e. cooling or heating, is determined based
on the following parameters:
■ Unit on/off status [status]: Unit running status.
■ Control type [ctrl_typ]: Local, Remote or Network.
■ Local heat/cool selection [hc_sel]: Heat/Cool selection when
the unit is running in Local mode.
■ Remote heat/cool selection [onsw_cr]: Heat/Cool selection
when the unit is running in Remote mode.
■ Network heat/cool selection [HC_SEL]: Heat/Cool selection
when the unit is running in Network mode.
■ Outdoor air temperature [OAT]: Heat/Cool setpoint selection
when the automatic changeover has been enabled.
Heating/
On/Off Control Cooling
status type selection in
local mode
off - -
on local cooling
on local heating
on remote -
on remote -
on network -
on network -
COOLING
Outdoor Air
Temperature
Cooling
threshold
Heating/
Heat/
Cooling Operating
Cool
contact in mode
select
local mode
- - cooling
- - cooling
- - heating
on cooling - cooling
on heating - heating
- cooling cooling
- heating heating

6.3 - Heating/Cooling selection

Heating/Cooling selection applies to chillers with the boiler and
heat pumps. Heating/cooling selection can be controlled in various
ways, depending on the active operating type. By default, the
cooling mode is selected.
Heating/Cooling selection can be determined:
■ Locally at the unit using the HC_SEL item in the GENUNIT
menu
■ Remotely via the heating/cooling selection contact, if the unit
is in the Remote mode
■ Via a network command if the unit is in the Network mode
Heating/Cooling mode can be set manually by the user or
automatically by the control. When heating/cooling is automatic, the
outdoor air temperature determines the heat/cool/standby
changeover (see the SETPOINT menu for cooling and heating mode
changeover thresholds). The automatic changeover is optional and
requires user configuration (GENUNIT – General Parameters).
To set cooling / heating / auto changeover
1. Navigate to the Main menu.
2. Select General Parameters (GENUNIT).
3. Set Heat/Cool Select [HC_SEL].
Heat/Cool Select [HC_SEL]
0 Cooling
1 Heating
2 Automatic changeover
To set cool / heat changeover setpoint
1. Navigate to the Main menu.
2. Select Setpoint Configuration (SETPOINT).
3. Set Cool Changeover Setpt [cauto_sp]
or Heat Changeover Setpt [hauto_sp].
Cool Changeover Setpt [cauto_sp]
3.9 to 50°C 23.9°C
39 to 122°F 75°F
Heat Changeover Setpt [hauto_sp]
0 to 46.1°C 17.8°C
32 to 115°F 64°F
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