Mitsubishi Electric FDT125VNVF Technical Manual page 289

(3) Method for connecting the accessory pipe (Models FDC200,250)
Be sure to use the accessory pipe to connect the operation valve on the gas
side with the field pipe.
① Referring to Table ① and Table ②, prepare the straight pipe and the elbow in the field,
which are used in the construction examples
② Firstly, use the accessory pipe to assemble the connecting pipe assembly outside the
outdoor unit.
As shown in the figures of construction examples
direction(chain double dashed line), braze the accessory pipe and the parts prepared
in the above ①.
③ After assembly of the connecting pipe, connect it to the service valve on the
gas side inside the outdoor unit.
Tighten the flare nut with appropriate torque.
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.
Table ① Parts used for the connecting pipe assembly
No. Name Qty.
1 Accessory pipe A 1
Straight pipe ①
2 1
Straight pipe ②
3 1 or 0
4 Elbow 1 or 0
Table ② Length of the straight pipe (prepared in the field)
Pipe size
Straight
φ22.22×t1.6
pipe①
Straight
φ22.22×t1.6
pipe②
Be sure to use pipes of 1/2H material, and wall thickness above 1mm. (Pressure resistance of O-type pipe is not enough)
●
Switch ON SW5-1 on the control PCB, if O-type pipe must be used and bent with the bender.
●
During heating operation, the high-pressure protection may be actuated under the condition lower than the normal pressure,
and the heating capacity may decrease.
About brazing
Be sure to braze while supplying nitrogen gas.
If no nitrogen gas is supplied, a large amount of impurity
(oxidized fi lm) will be generated, which may clog the capillary
tube and the expansion valve, resulting in fatal malfunction.
Straight pipe φ22.2(OD)
to be procured locally
applicable to the connecting direction.
~
A D
applicable to the connecting
~
A D
Remarks
Accessories
Procured in the field
Procured in the field (Not required for downward direction)
Procured in the field (Not required for downward direction)
Downward Forward
above 415mm 185~235mm
- above 125mm
Branching pipe set can be used by using the accessory pipe B.
●
When φ22.22(OD) size of the indoor unitgas pipe is used, the
accessory pipe B is unnecessory.
Accessory pipe A
Field piping φ22.2(OD)
Elbow to be
procured locally
Position for the
accessory pipe
Rightward Backward
185~235mm 185~235mm
above 125mm above 405mm
Branching pipe set
(DIS-WB1,DIS-TB1)
Accessory pipe B
※In case of V-multi
288
- -
'12 • PAC-T-174
PSB012D917C
PSB012D917C
A B
ID22.22
OD25.4
ID22.22
1 pc
1 pc
Appropriate torque
φ19.05
100~120N·m
Position for connecting
the service valve on
the gas side
Inner face of
the base
(44)
F
F