Acson international A4AC100C, Technical Manual

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5
2. FEATURES
REFRIGERANT CIRCUIT
Models AMAC/A4AC80~150C/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. This will
improve the reliability and energy efficiency of the unit, especially during low loading operations. Each circuit
is factory brazed and evacuated before accurately charged with refrigerant to ensure optimum performance.
Because each circuit is separated, there is no danger of cross-contamination should either one of the
compressor experiences a burnt-up. Each circuit is also equipped with a carefully sized thermostatic expansion
valve (for cooling only units) to give optimum performance characteristic. For the heatpump version, the
expansion process is done with capillary tubes.
SCROLL COMPRESSOR
S
croll Compressors are used (for model which is available) for the units (AMAC/A4AC20C/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.
TANDEM COMPRESSOR
A5AC 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 A5AC40/50CR and 2 steps capacity loading (0-50-100%) for A5AC30/
55CR.
CONDENSER FAN MOTOR
M
odels AMAC/A4AC80~150C/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.
EVAPORATOR
The heat exchanger is made of stainless steel plates closely arranged and brazed together (BPHE) to ensure
high heat exchange efficiency. For models AMAC/A4AC80~150C/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).
SAFETY PROCETECTION
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 A4AC/AMAC80~150C/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, AMAC/A4AC20~60C/CR does come with a 22 L or 40 L (refer to specification) water buffer tank.