Hitachi YUTAKI Series - Page 38

Water pipe
installation
Service Manual
36
Piping work connection considerations
SMGB0066 rev.0 - 12/2009

note
(1)
- The shaded part of the pipe system below. (Excluding the expansion tank (cistern))
Calculate and ensure that the water volume in the system is equal or greater than the larger value obtained from:
Protective water volume for product1.
Minimum water volume for temperature drop during defrost operation2.
Whentheminimumwatervolumecannotbeensured,useaBuffertanktocompensatetheshortage(<0)ofwater(2).See
gurebelow.
Expansion tank
Pump
Yutaki unit
Load
system
Expansion tank
Pump
Yutaki unit
Buffer tank
Load
system

note
(2)
- Shortage = Minimum water volume – Water volume in circulation system
The following part shows the minimum water volume in the system for product protection and temperature drop during
defrost operation.
1.
Ensurethatthewatervolumeisequalorgreaterthanthoseshownbelow,inordertoreduceON/OFFfrequencyoftheunit
atnoloadorextremelightload.Whenwatervolumeislessthanthevolumeindicated(minimumwatervolume),compressor
operationfrequentlystopsatlightload,whichmayresultinshorterlifeorfailure.
Model
ON/OFF
Temp. differential
   
4ºC 28 38 46 56
3ºC 36 48 58 70
2ºC 50 65 80 96
1ºC 80 107 130 156
(Units are in ltrs.)