Copyright © D 369 -10/00
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Cooling Unit
15 16
Cooling
Cooling
Thermostat
28 29
Com tN1/2
5
tN1
6
30 31
Indr
6
Item
Menu
UnOcc 1
°
F
View
Cooling Unit
15 16
Cooling
Display RTU
Section B2: Cooling Enable
COOLING ENABLE (ENBL)
The
Cooling relay can be used to enable a cooling system, which can be
controlled by a cooling thermostat. The changeover between heating
and cooling is described in the Heat / Cool Changeover section.
HEAT / COOL CHANGEOVER
The changeover between heating and cooling is based on whether or not a display RTU is connected to zone 6 (
tN1 6). If a display
RTU is connected to zone 6 (
tN1 6), the changeover between heating and cooling is selected at RTU 6. A pointer in the lower right
hand display of the RTU indicates that this RTU is the designated heat / cool RTU. Heat / cool changeover can be achieved
automatically or manually through the RTU. The MODE adjustment in the Adjust menu of RTU 6 allows the selection between HEAT,
COOL, AUTO or OFF. When HEAT is selected at RTU 6, the cooling system is locked out and only heating is allowed as required.
When COOL is selected at RTU 6, the heating system is locked out and all the heating zones assigned to the cooling group shut off.
Cooling is then allowed to operate as required. When AUTO is selected at RTU 6, the changeover between heating and cooling occurs
based on the Cooling Interlock function. Cooling is then allowed to operate as required. When OFF is selected at RTU 6, zone 6
becomes inactive and cooling operation is disabled. If a display RTU is not connected to zone 6 (
tN1 6), the changeover between
heating and cooling is automatic.
COOLING WHILE FLOOR WARMING
The 369 can use a 063 display RTU to provide floor (slab) and air temperature control. The 063 RTU has a built-in air sensor which
is used to control the heating and cooling air temperature, while a slab sensor connected to the 063 RTU controls the floor (slab)
temperature. During mild conditions the floor (slab) is maintained at a minimum temperature, and as the outdoor temperature drops
the floor (slab) will rise above the minimum setting and the air sensor takes over. As the outdoor temperature rises and cooling is
required, the control targets the cooling setpoint and the floor (slab) is still maintained at a minimum temperature.
Note:
During mild conditions, it is possible to overheat the space if the floor (slab ) is maintained at a minimum temperature.
Section B3: Cooling Control
COOLING CONTROL (CTRL)
A display RTU connected to zone 6 (
tN1 6) can be used to control a heating zone as well as the cooling group. This RTU is designated
as the controlling device for the cooling system. The actual cooling “room” temperature is an average of the room temperature of all
the zones assigned to the cooling group. The desired cooling temperature is set using the COOLING adjustment in the Adjust menu
of RTU 6. When cooling, the 369 varies the on time of the
Cooling relay based on a cycle length. The cooling cycle length is adjustable
through the COOL CYC setting in the Control Adjust menu of the control. If COOL CYC is set to AUTO, the control automatically
calculates a cooling cycle length. During every cycle, the control turns on the
Cooling relay for a specific on time. The required on
time is calculated based on the PID response of the cooling group during the previous cycle period. If the cooling group requires more
cooling, the on time is increased, and if the cooling group requires less cooling, the on time is reduced. The changeover between
heating and cooling is described in the Heat / Cool Changeover section.
Note:
If a non-display RTU is connected to
tN1 6 or if an indoor sensor is connected to Indr 6, cooling control (CTRL) can not be
selected.
- 01/09
- 01/09
