Mitsubishi Electric FDT125VNVF Technical Manual page 347

(c) Outdoor inverter PCB replacement procedure
• Since the following precaution is the important contents for safety, be sure to observe them.
WARNING and CAUTION are described as follows:
！ WARNING
！ CAUTION
• Securely replace the PCB according to this procedure.
If the PCB is incorrectly replaced, it will cause an electric shock or fire.
• Be sure to check that the power source for the outdoor unit is turned OFF before replacing the
PCB. The PCB replacement under current-carrying will cause an electric shock or fire.
• After finishing the PCB replacement, check that wiring is correctly connected with the PCB before
power distribution. If the PCB is incorrectly replaced, it will cause an electric shock or fire.
• Band the wiring so as not to tense because it will cause an electric shock.
Replace the inverter PCB according to the following procedure.
1) Model FDC71VN
1) Model FDC100VN, 125VN, 140VN
a) Replace the PCB after elapsing 3 minutes from power OFF.
Replace the PCB after elapsing 3 minutes from power OFF.
a)
(Be sure to measure voltage (DC) on both capacitor terminals located in controller back, and check that the
(Be sure to measure voltage (DC) between T26 and T27 on inverter PCB, and check that the voltage is
voltage is discharged sufficiently.(Refer to Fig.1))
discharged sufficiently (10V or less). (Refer to Fig.1))
b) Take off the connection of inverter PCB terminal block connector and remove the screw of power transistor then
b) Take off the connection of inverter PCB terminal and connector, and remove the screw of power transistor (IC10),
remove the PCB. Wipe off the silicon grease neatly on the controller's radiation heat fins.
active filter (IC2), and diode stack (DS1) then remove the PCB. Wipe off the silicon grease neatly on the controller's
c) Refer to table1 for the setting of switch (JSW10,11) of new PCB.
radiation heat fins. (Refer to Fig.1 and 2)
d) Before installing the power transistor on the new PCB,Apply uniformly a bundled of silicon grease first on the
c) Refer to table1 for the setting of switch (JSW10, 11) of new PCB.
surface of power transistor.Make sure it is applied to prevent damage on power transistor.
d) Before installing the power transistor (IC10), active filter (IC2), and diode stack (DS1) on the new PCB, apply
e) Tighten the screw of power transistor on inverter PCB and connect the terminal block.Confirm the connection and
silicon grease equally to the their surface. (Make full use of the silicon grease.) They may be damaged unless
don't use soldering in the connection.Tighten properly the power transistor with a screw and make sure there is no
they apply it.
clearance gap.Power transistor can be damage if not properly tighten.(Recommended power transistor tightening
e) Tighten the screw of power transistor (IC10), active filter (IC2), and diode stack (DS1) on inverter PCB and connect
torque:0.98~1.47N∙m)
terminal and connector. Confirm the connection and there is not the half insertion. Tighten properly power
transistor, (IC10) active filter (IC2), and diode stack (DS1) with a screw and make sure there is no
Terminal block
slack. They can be damage if not properly tighten. (Recommended tightening torque: power transistor
TB1
(IC10)1.2±0.1 and active filter (IC2)0.98±0.1, diode stack(DS1) 0.5±0.1 Unit N·m
TB2
CNG2
T22
(WHITE)
TB6
T21
(RED)
TB5
T24
(YELLOW)
TB7
CNI4
TB8
TB9
Parts arrangement view
T27 T25
(BLUE) (YELLOW)
Parts arrangement view
Connectors are
not half inserted
Precautions for Safety
Indicates an imminently hazardous situation which will result in death or serious
injury if proper safety procedures and instructions are not adhered to.
Indicates a potentially hazardous situation which may result in minor or moderate
injury if proper safety procedures and instructions are not adhered to.
Parts No.
T30 (BLUE)
T28 (RED)
PCA565A151-1
SCREW OF POWER TRANSISTOR (IC10)
T29(WHITE)
Parts No.
JSW11
CNACT1
JSW10
CNI2
SCREW OF DIODE STACK (DS1)
T26 CNO1
(RED)
Table. 1 Switch setting
-1
-2
JSW10
JSW10
-3
-4
！
WARNING
！
CAUTION
Terminal block
TB10
TB11
Connector
CNI2
CNI4
Switch
JSW11
JSW10
Fig.1 Position of capacitor
SCREW OF ACTIVE FILTWER (IC2)
Fig. 1 Position of fastontab and terminal
Table. 1 Switch setting
OFF
- 1
OFF
OFF
- 2
OFF
JSW11
OFF
- 3
OFF
OFF
- 4
OFF
346
- -
'12 • PAC-T-174
PCA012D025D
Voltage measurement parts
after elapsing 3 minutes
from power OFF
Voltage measurement point
(T26 (red), T27 (blue))
-1 ON
- 1
ON
-2 OFF
- 2
ON
JSW11
-3 OFF
- 3
OFF
-4 ON
- 4
OFF
F