Congratulations
for
thermostat. Made with top quality materials rigourously abiding by safety rules,
the "PXA E" is easy to use and will be by your side for many years to come.
The PXA E regulation thermostats are control panels for fan coils for
wall-mounted installation.
They control the fan coil function in accordance with the mode set, the
room temperature and water temperature in the circuit to maintain the set
temperature in the room.
The panels must be wall-mounted; they must be used on four- or two-
®
pipe plus PLASMACLUSTER
connecting two On - Off valves to cut
off the supply of water to the coils or
®
one valve and a
air purifier.
Each control panel can control a
single fan coil.
The control panel only consists of
mains voltage (230V) electrical
circuits; all the inputs for the probes
and controls must therefore be
correspondingly insulated for this
voltage.
The valve servo commands must also
be scaled for 230V.
PXA meets the requirement of the
Low Voltage directives 73/23 (EN
60730-1, EN 60730-2-9, EN 60335-
1) and electromagnetic compatibility
directive 89/336 (EN 61000-4-1, EN
55011, 55022, 55014).
The panel may only be opened and
installed by specialised personnel.
Cut off the supply voltage before
removing the lid of the control
panel. Contact with live components
can cause dangerous electric shocks.
This is particularly true also for the
setting of contacts on the Sw1 and
Sw2 cut outs.
OPERATION
The thermostat's job is to keep the temperature set on selector (B)
constant in the room.
Frost Protection, with selector (A) in the OFF position, prevents rooms
that are unoccupied for long periods from falling to temperatures
below 7°C that would make them hard to heat when they are used
again. If the fan coil is fed with warm water it will start in AUTO until
the room temperature is 9°C.
The Frost Protection function must be programmed by the installation
engineer.
All Off, selector (A) in the OFF position, the fan coil is completely off.
VENTILATION
In the two-pipe system, the thermostat makes it possible to enable the
heating ventilation only if the temperature of the water exceeds 35° or
39°C (programmable in the installation phase); in the same way the
ventilation in cooling mode is only enabled if the water temperature
is less than 17°C or 22°C (programmable in the installation mode).
The ventilation is delayed compared with the start and turn off
commands.
The functions described on the one hand prevent unwanted cold
variation in winter functioning and on the other allow all the terminals
to come on and go off depending on the temperature of the water.
The ventilation mode is set with selector (A).
Manual mode (selector in position V1, V2, V3) the fan uses On-Off
cycles on the speed selected.
Automatic mode (selector in AUTO position) the fan speed is
managed by the microprocessor of the PXA.
The delay between opening or closing of the warm water valve and
the turning on or off of the fan can last for up to 2' 40".
6
purchasing
the
purifier systems with the possibility of
C
-
A
PXA
E Aermec
The panel comprises:
– (A) on-off selector switch and ventilation speed;
– (B) temperature selector;
– (C) blue / red/ fuchsia leds, operating modes (Cooling/ Heating/
Antifreeze/ Autotest)
– (D) yellow led, fan coil operation, Autotest.
+
AUTOMATIC CHANGE OVER : AIR SIDE
The control makes it possible to automatically set the fan coil
functioning mode at hot or cold.
- In the two-pipe no valve systems or those with probe up line
from the valve, the functioning mode change is determined by the
temperature of the water circulating in the plant.
- In the four-pipe no valve systems or with probe up line of the
valve,the functioning mode change is determined by the temperature
of the water circulating in the plant if this is at a value higher than
the enabling threshold. If the temperature of the water circulating is
lower than the disabling threshold, the functioning mode change is
determined by the difference between the temperature measured in
the room and the set temperature.
- In two-pipe systems with probe downline of the valve and in all the
systems without water temperature probes, the change of functioning
mode is determined by the difference between the temperature
measured in the room and the set temperature.
electronic
control
B
D
V1 = Minimum speed
V2 = Medium speed
V3 = Top speed
panel
with