Charging - Toshiba HFC R407C Service Manual

Charging the system with additional refrigerant
Adding the refrigerant
After the airtight test, replace the vacuum pump with a refrigerant bottle to charge the system.
Calculating the additional refrigerant required
The Super Multi contains sufficient refrigerant to operate an installation having 5 metres of pipework (when
delivered). The refrigerant amount at shipment does not include the refrigerant needed for the piping - so
first calculate this amount, and then add it.
The total refrigerant charge must be calculated by the weight and within a tolerance of ± 50 g.
Refrigerant charge amount shipped from the factory:
Outdoor unit model name
Charging amount (kg)
Maximum gas charge (kg)
The amount of additional refrigerant is calculated from the actual length of the liquid pipe.
To calculate the additional refrigerant volume, refer to the diagram and follow the steps below:
(i) The main pipe length is taken as the addition of pipes X, Y and Z.
(ii) The sub pipe length is taken as the addition of the two longest of the four (if 4 Multi Controllers).
(iii) The branch pipe lengths must be individually calculated using the 8 longest pipes.
(iv) Do not attempt to add gas above the maximum shown in the table above.
(v) For systems with one Multi Controller ignore the sub-pipe section within the additional gas charge
calculation.
(vi) When using three Multi Controllers, it is important that a reducer is used on the pipework for the third
Multi Controller. Pipework before the reducer is classed as main piping and after as sub piping.
Charging the system
• Keeping the outdoor unit valve closed, charge the refrigerant from the service port on the liquid side.
• If the specified amount of refrigerant cannot be charged - fully open all the outdoor unit's valves, then
perform the cooling operation with the valve at the gas side slightly closed.
• If leaks cause a shortage of refrigerant - recover the refrigerant from the system, and recharge with
new refrigerant to the total refrigerant charge.
• Prolonged operation with either an overcharge or deficiency in refrigerant will lead to a loss of
performance, increased running costs and will cause damage to the machine. Warranty will be void.
Refrigerant pipe installation
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