"Liquid" sensor

"Liquid" sensor This is in the liquid line of the outdoor coil. It begins the defrosting cycle after a period of 30, 60 or 90 minutes (as selected) has elapsed from the start-up or since the previous defrosting, when the temperature detected drops to -5°C or less. It stops the defrost cycle when the liquid temperature reaches 13°C or stays at a minimum of 7°C for at least 5 minutes. It prevents defrost in mild climates when it does not detect a sufficiently low temperature. The reading for the beginning of defrost of 30, 60 or 90 minutes is nominal. These periods are based on an outside temperature of 2°C, a highly unfavourable level which causes considerable frost formation. At lower temperatures the overall humidity content of the ambient air is lower, making it possible to postpone the defrost cycles, thus saving energy. For example, at -10°C outside temperature, the reading times for the beginning of defrost will be 60, 90 & 120 minutes. Balance point It prevents functioning of the support system when the outside temperature is higher than the balance point as adjusted on the plaque. In this way, we save the heater's functioning as long as the heat pump is capable of satisfying the building's requirements. The balance point can be adjusted between 14°C and -4°C. This avoids the necessity of fitting an additional outside thermostat.