Fujitsu AB* A12GATH, Design & Technical Manual

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„ „
CAUTION
Keep the "piping limitation" for correct operation.
„ z
Allowable height difference:
If the height difference between the indoor unit and outdoor unit is larger than the allowable value:
„ 
The pressure loss will be larger → Insufficient cooling and heating
„ 
The refrigerant in liquid pipe will flush → Refrigerant flow noise generate at indoor unit
„ 
The refrigerant oil will not return → Insufficient refrigerant oil resulting in compressor damage
If the height difference between indoor unit is larger than the allowable value:
„ 
The refrigerant flow balance will be poor → Insufficient cooling and heating (poor balance)
„ 
Refrigerant oil will collect in the piping or non-operating indoor units
→ Insufficient refrigerant oil resulting in compressor damage
„ z
Pipe length:
If the pipe length is longer than prescribed:
„ 
The pressure loss will be larger → Insufficient cooling and heating
„ 
Too much refrigerant will be charged → Liquid backs up resulting in compressor damage
„ 
The refrigerant oil will not return → Insufficient refrigerant oil resulting in compressor damage
„ z
Pipe size:
If the pipe size is larger than designated size:
„ 
The refrigerant flow velocity will drop. Refrigerant oil will not return to the outdoor unit.
→ Insufficient refrigerant oil resulting in compressor damage
„ 
The refrigerant in liquid pipe will flush easily → Insufficient cooling and heating
If the pipe size is smaller than designated size:
„ 
The refrigerant circulation volume will drop → Insufficient cooling and heating
„ 
The pressure loss will be larger → Insufficient cooling and heating
„ z
Indoor unit connected capacity:
If the indoor unit connected capacity is larger than the system capable capacity:
„ 
Insufficient system performance → Insufficient cooling and heating
„ 
When heating, refrigerant will collect in non-operating indoor units resulting in an insufficient
refrigerant circulation volume → Insufficient cooling and heating
„ 
The refrigerant oil will not return → Compressor damage
If the indoor unit connected capacity is too small compared to the system capacity:
„ 
The liquid return will be too great → Compressor damage
„ 
The refrigerant will concentrate in the operating unit
→ Continuous operation will become difficult due to triggering of the protection in response
to the pressure high-rise, etc., and noise will be generated by the refrigerant flow when heating
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