Hitachi CH-Box Installation Manual page 28

● Tightening Torque for Flare Nut before shipping
Item
Gas Pipe Flare Nut
Liquid Pipe Flare Nut
1. In case of 8 and 10HP type indoor unit connection:
Up to two 8 and 10HP type indoor units can be connected to the CH-Box within the "Maximum
Total Capacity of All Connected Indoor Units". Make sure to increase the pipe connection size by
using the appropriate accessory pipe.
2. In case of 8 and 10HP type indoor unit connection:
Only single unit per branch is allowed to be connected.
3. In case the number of indoor unit connection is less and the piping connections are left over:
● Unused piping connections must be sealed using the
closed flare nut originally attached.
It is unnecessary to attach closed-end piping.
Refrigerant leakage is caused by loosened flare nuts.
Ensure that they are sealed completely.
Use specified tightening torque according to the table
"Tightening Torque for Flare Nut before shipping"
above.
● Any piping connections can be left over.
4. In case there is plan for additional indoor units in the
future:
● Do not plan the piping size for additional indoor
units. Ensure to select the piping again in the future.
● Additional indoor units can be connected only after
the refrigerant is recovered.
(4) Piping Insulation
(a) After the air-tight leakage test, perform insulation work as shown below.
Upstream (Outdoor Unit Side)
Insulation
(Field-Supplied)
High/Low Pressure Gas Pipe
Low Pressure Gas Pipe
18
Tightening Torque
75+7 N m (55.3+5 ft
●
38+4 N m (28.0+3 ft
●
NOTICE
Clamp (Two each)
(Field-Supplied)
Liquid Pipe
Insulation
(Field-Supplied)
Clamp (Accessory)
Insulation
(Field-Supplied)
lbs)
●
lbs)
●
CH-Box
Use three
connection ports.
Above figure illustrate the example of CH-AP04MSSX.
CH-Box
Insulation
(Accessory)
Gas Pipe
Downstream (Indoor Unit Side)
Example;
In case one of the
piping connection is
unused, ensure the
closed flare nut originally
attached is secured.
(For gas and liquid sides)
Clamp
(Accessory)
Insulation
Insulation
(Field-Supplied)
Liquid Pipe
P5417025-rev.1