Carrier 30RQ Operation And Maintenance Instructions page 30

Depending on the current operations, the active setpoint
can be selected by choosing the item in the Information
menu, with the user's volt-free contacts, with network
commands or with the setpoint timer program (schedule 2).
Local operating mode
Heating/cooling operating Local setpoint selection
mode
Cooling sp 1
Cooling sp 2
Cooling [2] Auto
Cooling [2] Auto
Cooling Auto
Cooling Auto
Heating sp 1
Heating sp 2
Heating Auto
Heating Auto
Remote operating mode
Heating/cooling operating Local setpoint
mode selection
Cooling [2] sp control
Cooling
Cooling
Cooling [2]
Cooling [2]
Cooling [2]
Heating
Heating
Remote operating mode - dual-circuit units
Parameter status
Heating/cooling operating mode
Cooling
Cooling
Cooling [2]
Cooling [2]
Heating
Heating
[2] Only with energy management option.
5.6.2 - Reset
Reset means that the active setpoint is modified so that
less machine capacity is required (in cooling mode, the
setpoint is increased, in heating mode it is decreased). This
modification is in general a reaction to a drop in the load.
For the Pro-Dialog control system, the source of the reset
can be configured in the User 1 configuration: it can be
provided either by the outdoor temperature (that gives a
measure of the load trends for the building) or by the return
water temperature (delta T that gives an average building
load) either for the reset setpoint based on a 4-20 mA input
(with energy management option) or based on the room
temperature, using a room temperature sensor (when the
energy management option is used). In response to a drop
in the outdoor temperature or to a drop in delta T, the
cooling setpoint is normally reset upwards in order to
optimise unit performance:
In the three cases the reset parameters, i.e. slope, source
and maximum value, are configurable in the Setpoints
menu (see section 4.3.8). Reset is a linear function based
on three parameters.
30
Ice storage
configuration [2]
Activated
Activated
Deactivated
Ice storage
configuration [2]
Activated
Activated
Activated
Ice storage configuration [2]
Activated
Activated
The following tables summarise the possible selections
depending on the control types (local, remote or CCN)
and the following parameters:
• setpoint select in local control: item #13 of the Infor-
mation menu permits selection of the active setpoint,
if the unit is in local operating type.
• Heating/cooling operating mode.
• Control contacts 2: status of control contact 2.
• schedule 2 status: schedule for setpoint selection.
Ice storage contact
status [2]
Open
Closed
Ice storage contact
status [2]
Open
Closed
Ice storage contact status [2]
Open
Closed
• A reference at which reset is zero (outdoor
temperature or delta T - no reset value).
• A reference at which reset is maximum (outdoor
temperature or delta T - full reset value).
• The maximum reset value.
Reset example in cooling mode based on the outside
Legend
A Maximum reset value
B OAT or delta T for no reset
Schedule 2 status Active setpoint
Cooling setpoint 1
Cooling setpoint 2
Unoccupied Ice storage setpoint
Unoccupied Cooling setpoint 2
Occupied Cooling setpoint 1
Unoccupied Cooling setpoint 2
Heating setpoint 1
Heating setpoint 2
Occupied Heating setpoint 1
Unoccupied Heating setpoint 2
Control contact 2 Active setpoint
Control setpoint
sp 1 (open) Cooling setpoint 1
sp 2 (closed) Cooling setpoint 2
Open Cooling setpoint 1
Closed Ice storage setpoint
Closed Cooling setpoint 2
sp 1 (open) Heating setpoint 1
sp 2 (closed) Heating setpoint 2
Schedule 2 status Active setpoint
Occupied Cooling setpoint 1
Unoccupied Cooling setpoint 2
Unoccupied Ice storage setpoint
Unoccupied Cooling setpoint 2
Occupied Heating setpoint 1
Unoccupied Heating setpoint 2
temperature
Outdoor temperature (OAT)
Evaporator Delta T
C OAT or delta T for full reset
D Building Load