Carrier 25VNA Service Manual page 22

B
WARNING!
Disconnect &
lock -out power
and recover
system charge
Remove the
molded plug from
the thermistor
fusite on the
compressor
(See Fig. 19)
Measure
resistance
between each of
the three fusite
pins and ground
(See Fig. 22)
Is there continuity
Change the
between any of the
compressor
pins and ground?
Yes
No
The molded plug
harness is
grounded - replace
it
Install new
molded plug
assembly and
route wires
carefully
A
A
Reset scroll temp
fault at system
controller &
remove power to
drive to reboot
Put system back
into operation
Check system
refrigerant
charge & air flow
Check for
restricted
refrigerant flow
and/or high
superheat
Measure
discharge temp
(within 6" of
compressor )
Discharge
temp less
than 250 °F?
No
Yes
Normal
operation -
monitor
Fig. 13 – Scroll Temp Troubleshooting - - Part 2
22
Confirm phasing
is correct to Confirm
compressor operation inside
( yellow, black, compressor/unit
red wires on temperature &
drive output, speed range
(See Fig. 23)
Adjust expansion
device to 10-20°F
superheat
If scroll temp
fault still exists,
change
compressor
A11553