Carrier Touch Pilot Junior - Heating, Cooling, and Standby Modes; Operating Mode Control Logic

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8.2 - Heating/Cooling/Standby
The control determines the heat/cool state of the unit.
Chillers tted 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 insufcient. 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 congured otherwise.
The pump may be stopped depending on pumps
conguration (
pump_sby, PUMPCONF – Pump
Conguration).
Figure 3: Heating /Cooling changeover for heat pumps and chillers tted with a boiler
8.2.1 - Operating mode control
The operating mode, i.e. cooling or heating, is determined
based on the following parameters:
• Control type: Local, Remote or Network.
• Local heat/cool selection [hc_sel]: Heat/Cool
selection when the unit is running in Local mode.
Control type Heat / Cool (Local) Heat / Cool (Remote) Heat / Cool (Network) Outdoor Air Temperature ** Operating mode
local cool - - - cool
local heat - - - heat
local auto* - - > cauto_sp + 1 cool
local auto* - - < hauto_sp -1 heat
local auto* - - hauto_sp + 1 < oat < cauto_sp -1 standby
local - on_cool - - cool
local - on_heat - - heat
local - on_auto - > cauto_sp +1 cool
local - on_auto - < hauto_sp - 1 heat
remote - on_cool - - cool
remote - on_heat - - heat
remote - on_auto - > cauto_sp + 1 cool
remote - on_auto - < hauto_sp - 1 heat
remote - on_auto - hauto_sp + 1< oat < cauto_sp - 1 standby
network - - cool - cool
network - - heat - heat
network - - auto* > cauto_sp + 1 cool
network - - auto* < hauto_sp - 1 heat
network - - auto* hauto_sp + 1 < oat < cauto_sp - 1 standby
* If auto changeover has been selected through user conguration; otherwise, by default set to “cooling”.
** cauto_sp = cooling changeover setpoint; hauto_sp = heating changeover setpoint; oat = outdoor air temp.
• 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.