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REFRIGERANT CIRCUIT
• All chiller units are pre-charged with R410A refrigerant.
SPECIAL PRECAUTIONS WHEN DEALING WITH R410A UNIT
• R410A is a near azeotrope refrigerant blend of hydro fluorocarbon (HFC) which is environmental friendly. It has Zero
Ozone Depletion Potential (ODP=0) and this conforms to Montreal Protocol regulations. It has no flame propagation and
a low toxic refrigerant (rated as A1 by ARI). R410A is a mixture of R32 (50%) and R125 (50%).
• POE oil is used as lubricant for R410A compressor, which is different from the mineral oil used for R22 compressor.
During installation or servicing, extra precaution must be taken not to expose the R410A system too long to moist air.
Residual POE oil in the piping and components can absorb moisture from the air.
• Refrigerant R410A is more easily affected by dust of moisture compared with R22, make sure to temporarily cover the
ends of the tubing prior to installation.
• No additional charge of compressor oil only is permitted.
• No refrigerant other than R410A is permitted.
• Tools designed specifically for R410A only.
i) Manifold gauge and charging hose
ii) Gas leak detector
iii) Refrigerant cylinder/charging cylinder
iv) Vacuum pump c/w adaptor
v) Flare tools
vi) Refrigerant recovery machine
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! CAUTION
• R410A must be charged as liquid. Usually R410A cylinder is equipped with a dip-pipe for liquid withdrawal.
If there is no dip-pipe, the cylinder should be inverted so as to withdraw liquid R410A from the valve.
• Do not top-up when servicing leak, as this will reduce the unit performance. Vacuum the unit thoroughly and then
charge the unit with fresh R410A according to the amount recommended in the specification.
• Do not touch the compressor or refrigerant piping when the chiller is running. If necessary wear protective gloves.
Operation of the mini chillers without any fan speed control is limited to an ambient temperature of 17°C. With the fan speed
control, the units are able to operate down to -5°C.
The fan speed controller does not come as a standard item in the mini chiller units. It is field-installed.
All mini chillers will have a 1/4" access valve provided for along the liquid line of the refrigerant circuit. This valve is for
direct pressure connection to the fan speed controller.
To install the fan speed controller, screw in the female adaptor to the 1/4" access valve. Use a pair of spanners to tighten
properly (max. torque 15 Nm). See Fig. 12. Ensure there is no leakage at the joint.
Wire the fan speed controller to the terminal blocks. See Fig. 13.
FAN SPEED CONTROLLER (OPTIONAL)
ISOLATOR SWITCH FIELD INSTALLATION
The isolator switch does not come as standard item with the units. It is advisable to have it field installed. The isolator switch
must be capable of making, carrying and breaking currents under normal circuit condition. It must be of AC23A duty and fully
compliant to IEC: 947-3.
For isolator switch selection, check the starting and running consumption specified in the Table B. Be sure to connect a ground
wire from incoming power supply, either direct to the terminal box panel or use an auxillary ground terminal in the isolator
switch. To install an isolator switch, wire it to the terminal block as shown in Figure 11.