Heating; Water Heating - Sinclair S therm Series Service Manual

temperature, the main unit will stop as per the shutdown frequency but the water pump keeps normal operation.
When it is detected that the leaving water temperature of the plate heat exchanger is equal to or larger than
the freeze protection withdrawing temperature, freeze protection will stop. At this point, once the compressor has
stopped for three minutes and conditions for startup have been satisfied, the compressor will run for cooling.

2.2 Heating

2.2.1 Control to the Compressor
When the unit is controlled by the leaving water temperature, the operating frequency of the compressor will be
adjusted by the temperature difference in the way that it increases as the temperature difference goes up and it
decreases as the temperature difference goes down. When the compressor reaches the minimum frequency but
the temperature frequency is still quite large, the unit will shut down (temperature difference= actual leaving water
temperature-leaving water temperature set point).
2.2.2 Over-temperature Protection
When the compressor is running and it is detected that the leaving water temperature of the auxiliary electric
heater is higher than the over-temperature protection temperature, the compressor will lower its frequency to the
minimal. Then if it is still detected that the leaving water temperature of the auxiliary electric heater is higher than
the over-temperature protection temperature, all loads except the water pump of the main unit and the 4-way valve
will stop. Over-temperature protection will stop until the leaving water temperature of the auxiliary electric heater is
lower than the over-temperature withdrawing temperature. After that, the unit will resume normal operation.
2.2.3 Control to the Optional Electric Heater
When the Optional electric heater is deactivated through the wired controller, it will never come into operation.
When it is activated, it will run based on the outdoor temperature.

2.3 Water Heating

Water heating can be achieved by either the solar system or the main unit (heat pump).
2.3.1 Water Heating by the Main Unit
(1) When the outdoor temperature is out of the operation range, the compressor will not start, and water
heating will be done by the water tank heater.
(2) When the outdoor temperature is within the operation range, water heating will be done by the main
unit. The output frequency of the compressor will be adjusted by the difference between the water tank
temperature set point and the actual water tank temperature.
(3) Control to the Water Tank Electric Heater
when the water tank temperature set point is lower than the maximum value of the water heating range
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of the main unit, the auxiliary electric heater of the main unit will run depending on the temperature
difference, and the water tank keeps shut-down.
when the water tank temperature set point is higher than the maximum value of the water heating range
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of the main unit but the actual water tank temperature is lower than the maximum value of the water
heating range of the main unit, the auxiliary electric heater of the main unit will run depending on the
temperature difference. If the actual water tank temperature is higher than the maximum value of the
water heating range of the main unit, the water tank heater will start. At any time, only one between the
auxiliary electric heater and the water tank heater is allowed to run.
(4) Over-temperature Protection for Water Heating
When the compressor is running, if it is detected that the leaving water temperature of the auxiliary electric
heater of the main unit is higher than the over-temperature protection temperature, the compressor will lower its
operating frequency until it reaches the minimal operating frequency. At this point, if it is still detected that leaving
water temperature is still lower than the over-temperature protection, all loads except the water pump of the main
unit and the 4-way valve will stop. Over-temperature protection will exit when the leaving water temperature is
lower than the over-temperature protection temperature. Then, the main unit will resume normal operation.
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