AIR COOLED MINI CHILLER
Models MAC/M4AC080~150C/CR has been designed with two separate refrigerant circuits, i.e. it has two compressors. By doing so, the unit has part loading capabilities, i.e. 0-50-100% of rated capacity.
Scroll Compressors are used (for model which is available) for the units (MAC/M4AC020C/CR using rotary compressor) to give quiet and reliable performance over a wide operating temperature range. However, in order to protect the compressors from damage, a phase protector (for model which is available) is provided to prevent the compressors from rotating in the wrong directions.
M5AC models are using R410A rotary compressors in tandem configuration. Tandem compressors are highly efficient and cost saving. It reduces mechanical losses, minimize gas flow losses and turbulence. There are 3 steps capacity loading (0-40-60-100%) for M5AC040/050CR and 2 steps capacity loading (0-50-100%) for M5AC030/055CR.
Condenser Fan Motor
Models MAC/M4AC080~150C/CR is equipped with two high air flow propeller fan blades which are made of metal. The fans are driven vertically by weather proof motors which are single phase type.
The heat exchanger is made of stainless steel plates closely arranged and brazed together (BPHE) to ensure high heat exchange efficiency. For models MAC/M4AC080~150C/CR, the water flow through the BPHE in a channel on its own, while because of the two compressors, the refrigerant flows through another two separate channels. The refrigeran t will either be in a counter-flow or parallel-flow with respect to the water, depending on the mode of operation (cooling or heating).
The safety protections provided for the mini chiller are:
a) High and low pressure switches
b) Differential water flow switch
c) Compressor, water pump and fan motor overload protectors
d) Anti-freeze protection sensor
During abnormal condition, chiller panel controller will turn off the unit and then display the faults of operation.
Water Tank And Piping Connection
The models M4AC/MAC080~150C/CR does not come with a water buffer tank. However, the unit does come with an 8 liters expansion tank. Besides that, an optional 135L hydraulic tank is also available. The external water piping connection can be made either from the left or right side of the unit. Connection is done with Ø1-1/4 “ female thread couplings for both supply and return pipes. Meanwhile, MAC/M4AC020~060C/CR does come with a 22 L or 40 L (refer to specification) water buffer tank.
The chiller unit has several anti-freeze protection features:
1. Brazed plate heat exchanger anti-freeze The BPHE has a strip heater around it to prevent water freezing inside
2. Auto mode
The chiller controller will force on the unit to the heat mode if the outdoor ambient air temperature becomes too cold.
In order to facilitate of the controller, a rocker switch is provided to power-off the supply to the PCB. However, switching off the switch will not disconnect the main incoming power supply to the chiller unit.