Mitsubishi Heavy Industries V Multi FDC71VNX Technical Manual page 160

(V) Model FDC250VSA
Replace the inverter PCB (Fig.1) according to the following procedure.
1) Replace the PCB after elapsing 3 minutes from power OFF.
In the situation that harnesses are connected to control PCB, be sure to measure voltage (DC) of two places ((A),
2
)
(B)) and check that the voltage is discharged sufficiently. (Refer to Fig.2)
3) Remove the harnesses from bands, clips and connectors on the control PCB. Then, remove the appointed screws
(4 places) of a control. (Refer toFig.3)
4) Open main layer and measure voltage (DC) of aplace (C) and check that the voltage is discharged sufficiently.
(Refer to Fig.4)
5) Disconnect connectors from the inverter PCB (Refer to Fig.1), remove a snubber capacitor (Refer to Fig.4) and
harnesses ("P", "N" ,"U", "V" and "W"), and exchange the inverter PCB then. In the situation of being opening
main layer, do not press the control from above. It will cause the product deformation or injury.
6) Match the setting of switches (JSW10, 11) of new PCB with former PCB.
7) After exchanging the inverter PCB, install the snubber capacitor to power transistor (Refer to Fig.5), and reconnect
the connectors and the harnesses as before. (Confirm the connectors are not half inserted.)
Be careful not to pinch the wiring at the time of closing main layer. The wiring is damaged, and it will cause a short
circuit or fire.
CNA
Fig.1 Parts arrangement view of inverter PCB
(A) Power source for control PCB : CNA1, 1 –3 pin or CNA2, 1 - 4 pin
※：Presence and shape of electric component
may vary according to a model.
(B) Power source for fan motor (DC) : CNA2, 1 - 3 pin or CNA1, 1 - 4 pin
Fig.2 Voltage measurement points
159
- -
PCB012D057A
CNI2
After elapsing 3 minutes
from power OFF
CNR
JSW10,11
LED1
Connectors are not
Parts No .
half inserted
(－) (＋)
or
(＋) (－)
(＋)
or
(＋)
(－)
(－)
'19 • PAC-T-327
D