Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual page 324

Model FDC250VSA
Model FDC250VSA
● Be sure to use the accessory pipe to connect the service valve on the gas side with the field pipe.
● Be sure to use the straight pipe （Procured at the field） shown in the table 1 applicable to the model of outdoor unit.
● When tightening the flare, connect the pipe securely by pressing the flared face of pipe against the service valve.
● When brazing between the pipe in place and the attached pipe, confirm that no excessive force is applied to the flare joint.
Otherwise gas could leak from the flare joint.
● Connect the attached pipe according to the following steps ① ‒ ⑤.
① Referring to Table 2 and Table 3, prepare the straight pipe and the elbow in the field, which are used in the construction
‒
examples applicable to the connecting direction.
A D
② Firstly, use the accessory pipe to assemble the connecting pipe assembly outside the outdoor unit.
（As shown in the figure of connecting examples
③ After assembling the connecting pipe, connect it to the service valve on the gas side inside the outdoor unit. Tighten the
flare nut with appropriate torque.
Proper torque
100 ‒ 120N・m
φ19.05
④ After connection of the connecting pipe assembly to the service valve on the gas side, braze the connecting pipe assembly
and the field pipe.
⑤ When connecting pipe contacts wiring, attach heat insulating material to the pipe in order to prevent from contacting of the
pipe and wiring. （If the wiring is rubbed with the pipe and the cover of wiring is teared, there is a risk of a short circuit or
an electric shock.）
About brazing
● Be sure to braze while supplying nitrogen gas.
If no nitrogen gas is supplied, a large amount of impurity
（oxidized film）will be generated, which may clog the capillary
tube and the expansion valve, resulting in fatal malfunction.
Table 1 Pipe specification
Single type FDC250V
FDC224KXZPE1
Multi type
FDC280KXZPE1
● Be sure to use pipes of 1／2H material, and wall thickness
above 1mm. （Pressure resistance of O-type pipe is not enough）
Table 2 Parts used for the connecting pipe assembly
No. Name
1 Accessory pipe A
2 Straight pipe ①
3 Straight pipe ②
4 Elbow
Table 3 Length and specification of straight pipe（Procured in the field）
A
Straight pipe ① 400mm or more 192.5 – 202.5mm 192.5 – 202.5mm
Straight pipe ②
A
Accessory pipe A x 1 pc
（Except FDC224KXZPE1）
Heat insulating material is attached
to the accessory pipe with band.
When installing the heat insulating
material, cut the band and retrieve it.
‒
A
Refrigerant line （one way） length（m）
≦35（m） φ22.22 x T1.0
≦70（m） φ25.4 x T1.0 or φ28.58 x T1.0
≦90（m）
φ19.05 x T1.0
≦120（m）
φ22.22 x T1.0
≦90（m）
φ22.22 x T1.0
≦120（m）
φ25.4 x T1.0 or φ28.58 x T1.0
Quantity Remark
1 Accessory
1 Procured at the field
Procured at the field（Not
1 or 0
required for downward direction）
Procured at the field（Not
1 or 0
required for downward direction）
Downward Forward
B
－
105mm or more
B
Accessory pipe B x 1 pc
（Only use for FDC250V）
● Branching pipe set can be used by
using the accessory pipe B.
When φ22.22（OD）size of the
indoor unit gas pipe is used, the
accessory pipe B is unnecessary.
.）
D
Rightward Backward
C D
210mm
155mm or more 370mm or more
323
- -
'19 • PAC-T-327
PSC012D028C
PSC012D028C
※In case of V-multi
（In case of FDC250V）
Accessory pipe A
Straight pipe ①
φ22.22（OD）to be
procured locally
Elbow to be
procured locally
Branching pipe set
（DIS-WB1G,DIS-TB1G）
Accessory pipe B
Field piping
φ22.22（OD）
Straight pipe ②
φ22.22（OD）to be
procured locally
C
D