Nibe AMS10 - Page 53

TROUBLESHOOTING THE POWER
TRANSISTOR
Checking the power transistor
Disconnect the connections to the compressor on the
inverter board PWB2 and measure between the connec-
tions in accordance with the table:
Normal values (Ω)Measurement points
AMS 10-12/-
16
AMS 10-8Connection (-
)
Connection
(+)
~ 1 MΩ0 and the
value in-
creases
NP
~ 300-400 kΩPN
0Several MΩ
and the value
rises
UP
VP
WP
~ 1.2 MΩ~ 650 kΩUN
VN
WN
~ 1.3 MΩ~ 670 kΩPU
~ 4.4 MΩPV
PW
0~ 650 kΩNU
~ 4.8 MΩNV
~ 4.9 MΩNW
Location of measurement points
The power transistor’s connection PP
The power transistor’s connection NN
Red connection to compressorU
White connection to compressorV
Black or blue connection to compressorW
AMS10-12
U
V W
P
N
AMS10-8
P
N
U V W
53Chapter 6 | TroubleshootingNIBE AMS10