Daikin VRV IV+ Service Manual page 262

3 | Components
To perform a power transistor check of the fan inverter PCB
Problem solved?
Service manual
262
Blown fuse on the fan inverter PCB?
No
Prerequisite: Stop the unit operation via the central controller.
Prerequisite: Turn OFF the respective circuit breaker.
Prerequisite: Remove the required plate work, see
1 Set the multimeter to diode measurement.
DANGER: RISK OF ELECTROCUTION
Confirm the rectifier voltage is below 10 V DC before proceeding, see
rectifier voltage" [
2 Check the fan inverter PCB in reference with the tables below.
a
a Fan inverter PCB A4P
b Connector P1
c Connector N1
d Connector X1A, pin U
e Connector X1A, pin V
f Connector X1A, pin W
VDC Com
P1 X1A, pin U
P1 X1A, pin V
P1 X1A, pin W
X1A, pin U P1
X1A, pin V P1
X1A, pin W P1
N1 X1A, pin U
Are the test results OK?
Yes
No
After all checking procedures listed above have been performed:
Action
Return to
procedures" [
PCB and continue with the next
procedure.
4
356].
c d e f
Ref VDC
O.L N1
O.L N1
O.L X1A, pin U
0,45 X1A, pin V
0,45 X1A, pin W
0,45 P1
0,45 N1
Action
Power transistors are OK. Return to
"Checking
Replace the fan inverter PCB, see
"Repair
"Checking
4
259] of the fan inverter
4
"3.15 Plate work" [ 315].
"To check the
b
Com
X1A, pin V
X1A, pin W
N1
N1
N1
N1
P1
4
procedures" [ 259].
4
procedures" [ 263].
REYQ8~20+REMQ5U7Y1B
VRV IV+ Heat Recovery
ESIE18-15B – 2020.05
Ref
0,45
0,45
O.L
O.L
O.L
O.L
0,75