13
DEFROST MANAGEMENT
The defrost process is activated during heating mode in the heat pump units, when the outside temperature is very
low and the coil of the external heat exchanger could be frozen.
To melt the ice defrost function will turn on, and brings about the inversion of the reverse cycle valve from heating
mode to defrost function.
For this control, the defrost cycle is done trough auxiliary printed boards.
The defrost auxiliary printed boards have 2 leds, one for the supply and other for the defrost.
When one circuit is on the defrost cycle, the led of its auxiliary printed board will be on.
If you press the button in the auxiliary printed board the defrost cycling will be on for this circuit.
DEFROST CYCLE SEQUENCE:
During defrost cycle, the inversion of the reverse cycle (from heating mode to defrost function), the outdoor fan
will stop and the inner fan keeps going on.
START DEFROST CYCLE
The defrost cycle begins when outdoor probe temperature reaches -3ºC.
END DEFROST CYCLE
The defrost cycle ends when outdoor probe temperature reaches 25ºC.
DELAY BETWEEN TWO DEFROST REQUESTS
The time between 2 defrost cycles will be calculated between the end of one and the beginning of the other and
it will be between 14 and 35 minutes depending on external conditions.
The defrost cycle is separately done for both circuits, it is not at the same time. When one circuit is on the defrost
cycle, the other one remains waiting.
POWER BOARD OF THE SYSTEM AT THE ELECTRICAL BOX OF THE AIR-CONDITIONING UNIT
- The board features a signaling green LED which flashes when unit is electrically supplied.
- The control features a minimum run timer, which ensures that once started in heating or cooling mode, the
compressor (and other associated components) remain running for a minimum of 5 minutes. The unit will not
respond to a change in mode for this period of time. This prevents premature wear of components. Please bear
this in mind when carrying out maintenance to the unit.
