Regulation Logic; Temperature Control; Close Control Units With Direct Expansion Coil - Lennox @DNOVA pCO1 User Manual

2 REGULATION LOGIC

2.1 Temperature control

The heating and cooling devices are managed based on the temperature value measured by the ambient (or
room temperature) probe. The measured temperature is compared to the set temperature (set point); the
devices are enabled based on the difference between the two values. The proportional band identifies the
air-conditioning unit working range and can take different values in heating and cooling mode. The dead
zone identifies the devices non-action zone round the set point. The following diagrams show the action of
the heating and cooling devices. The percentage values indicate the modulating valves opening range. The
warm and cold valves start and end opening parameters correspond to 0% and 100% respectively (default
values) and are different for the two valves; if need be, the values may be modified to delay opening start
and bring complete opening forward.

2.1.1 Close control units with direct expansion coil

HEATING
100%
19.5
3°C
Warm proportional band
1 HEATER
19.5
HEATER 1
19.5
BINARY MANAGEMENT
HEATER 3 HEATER 2
19.5 20.5
0-10 Volt WARM WATER VALVE
100%
0%
19.5
100%
0%
19.5
Three-position valve running time
4
0%
22.5
0.5°C
Dead z.
22.5
HEATER 2
21.5 22.5
HEATER 1
21.5 22.5
22.5
22.5 23.0
Temperature set
COOLING
0%
23.0 23.5
0.5°C
Dead z. Cold proportional band
1 COMPRESSOR
23.0 23.5
COMP.1
23.0 23.5
COMP.1 C1 c.c.
23.0 23.5 24.2
23.0
Opening start point (0%)
Opening end point (100%)
100%
26.5
3°C
Ambient
26.5
Ambient
COMP.2/
C1 capacity control
25.0 26.5
COMP.2 C2 c.c.
25.0 25.7 26.5
INNOV@-pCO1-IOM-0907-E
temp. (°C)
temp. (°C)
Ambient
temp. (°C)
Ambient
temp. (°C)
Ambient
temp. (°C)
Ambient
temp. (°C)