Carrier 40MAQB12B--3 - Outdoor Fan Speed Error Diagnosis (E8); E8 Outdoor Fan Speed Troubleshooting

51
E8(Outdoor fan speed has been out of control) diagnosis and
solution
Error Code E8
Malfunction decision conditions
When outdoor fan speed keeps too low (300RPM) or too high(2400RPM) for certain time, the unit stops
and the LED displays the failure.
Supposed causes
S Wiring mistake
S Fan ass'y faulty
S Fan motor faulty
S PCB faulty
Troubleshooting
Power o
ff
,
t
h
en restart t
h
e
un
i
t
3
m
i
n
u
t
e
s
l
ate
r
.
Is it s
ll
disp
l
aying t
h
e error cod
e
?
Power off, then restart the
unit 3 minutes later. Is it sll
displaying the error code?
S
h
u
t
o
ff
t
he
po
w
e
r
su
pp
l
y
,
ro
t
a
te
t
he
f
a
n
by
h
and
.
D
oes
it rotate proper
ly
?
Shut off the power supply,
rotate the fan by hand. Does
it rotate properly?
Th
e unit operates norma
lly
.
The unit operates normally.
Find out t
h
e cause and
ha
v
e
it
sol
v
ed
.
F
or
exam
p
l
e
,
whether the fan
i
s
blocked
or
th
e
sc
r
e
w
s
whi
c
h
fi
x th
e
fa
n
a
r
e
ghte
n
.
Find out the cause and
have it solved. For
example,
whether the fan
is blocked or the screws
which fix the fan are
ghten.
Check the wiring o
f
f
an
motor
.
A
r
e
all
t
he
connecons goo
d
?
Check the wiring of fan
motor. Are all the
connecons good?
No
Yes
No
Correct t
h
e connecon
s
.
Correct the connecons.
No
Replace the
f
an moto
r
Replace the fan motor
Yes
Yes
Rep
l
ace t
h
e main PC
B
Replace the main PCBNo
C
h
ec
k
w
h
et
h
er t
h
e main PCB
i
s norma
l
t
h
roug
h
index
1
?
Check whether the main PCB
is normal through index 1?
Yes
No