Technibel PHRIE Series - Electronic Expansion Valve Control; Water Circulating Pump Control

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4.10 FAN CONTROL
Performed by A3 board
• Cooling Mode:
The appropriate rotations per minute for the fan are determined in accordance with the outdoor air
temperature and the frequency of the compressor inverter.
The fan step is controlled between a range of W1 (Step 1) and WF (Step 16).
• Heating Mode:
The appropriate rotations per minute for the fan are determined in accordance with the outdoor air
temperature and the frequency of the compressor inverter.
The fan step is controlled between a range of W1 (Step 1) and WF (Step 16).
Note
: However, the fan is halted (Step 0) when defrosting is being carried out.
4.11 ELECTRONIC EXPANSION VALVE CONTROL
Performed by A3 board
The electrical expansion valve controls the amount of refrigerant that is allowed to flow in accordance with the
operation status.
The valve is adjusted in accordance with the discharge temperature (TD), the outdoor heat exchanger
temperature sensor (C1), the suction temperature sensor (TS), and the heat exchanger temperature sensors (E1
and E2).
• Cooling Mode:
Controlled so that the suction temperature (TS) - water heat exchange temperature minimum (E1 and E2)
is between 1°C and 5°C under normal conditions.
There are cases where the aperture opens wider than usual if the discharge temperature increases.
• Heating Mode:
Controlled so that the Suction Temperature (TS) - Outdoor heat exchange temperature (C1) is between
1°C and 5°C under normal conditions.
There are
4.12 WATER CIRCULATING PUMP CONTROL
Performed by A2 board -
see presentation § 3.2.4
In normal operation, water pump is actuated automatically by system control
(see details in the corresponding technical manual) :
-in heating mode when outdoor temperature is lower than the “non heating threshold”,
-during “Domestic Hot Water” cycle,
-in cooling mode (as soon as it is selected).
Anyway, it is possible to operate the circulating pump in a forced way; then water pump runs permanently. This
kind of operation can be needed for commissioning or maintenance (or operation without system control).
Forced circulating water pump operation:
- Make sure that the hydraulic circuit is ready (no leakage, pressure, valves open…).
- Press during 5 seconds the “RESET” button of the CWC2 control board.
The circulating pump starts (if it was stopped). This action has the priority to any control signal from the system.
The circulating pump indicator light “PP” flashes.