Midea MOAB30-09HFN8-QRD0GW, Service Manual

Page: 125 / 172

 Troubleshooting 16 
2.Field Maintenance
Possible causes of trouble
Po
w
er
fa
ilu
re
Bl
ow
n f
us
e or
v
ar
ist
or
Loos
e c
on
ne
ct
ion
s
Sho
rt
ed o
r br
ok
en w
ire
s
Sa
fe
ty
d
ev
ic
e o
pe
ns
Fa
ul
ty
th
er
m
os
ta
t /
ro
om
te
m
pe
ra
tu
re
se
ns
or
W
ro
ng
se
tti
ng
p
la
ce o
f t
em
per
at
ur
e s
en
so
r
Fa
ul
ty
tr
an
sf
or
m
er
Sho
rt
ed o
r o
pe
n c
apa
ci
to
r
Fa
ul
ty
m
ag
ne
tic
c
on
ta
ct
or
for
c
om
pr
es
sor
Fa
ul
ty
m
ag
ne
tic
c
on
ta
cto
r f
or
fa
n
Low
v
ol
ta
ge
Fa
ul
ty
st
eppi
ng
m
ot
or
Sho
rt
ed o
r g
ro
unde
d c
om
pr
es
so
r
Sho
rt
ed o
r g
ro
unde
d f
an m
ot
or
Unit will not start
☆ ☆ ☆ ☆ ☆ ☆
Compressor will not start but fans run
☆ ☆ ☆ ☆ ☆
Compressor and condenser (outdoor) fan will not start
☆ ☆ ☆
Evaporator (indoor) fan will not start
☆ ☆ ☆ ☆
Condenser (Outdoor) fan will not start
☆ ☆ ☆ ☆ ☆
Unit runs, but shortly stops
☆ ☆
Compressor short-cycles due to overload
☆ ☆
High discharge pressure
Low discharge pressure
High suction pressure
Low suction pressure
Unit runs continuously but insufficient cooling
Too cool
☆ ☆
Compressor is noisy
Horizontal louver can not revolve
☆ ☆ ☆
Test method / remedy
Te
st v
ol
ta
ge
Ins
pe
ct
fus
e t
ype
&
si
ze
Ins
pe
ct
c
onne
ct
io
ns
- t
ig
ht
en
Te
st c
irc
ui
ts
w
ith
te
ste
r
Te
st c
on
tin
ui
ty
o
f s
af
ety
d
ev
ic
e
Te
st c
on
tin
ui
ty
o
f th
er
m
os
ta
t /
se
ns
or
&
w
iri
ng
Pl
ac
e t
he t
em
per
at
ur
e s
en
so
r a
t t
he c
en
tr
al
o
f t
he
a
ir i
nl
et
gr
ill
e
Ch
ec
k c
on
tr
ol
c
irc
ui
t w
ith
te
ste
r
Ch
ec
k c
ap
ac
ito
r w
ith
te
ste
r
Te
st c
on
tin
ui
ty
o
f c
oi
l &
c
on
ta
cts
Te
st c
on
tin
ui
ty
o
f c
oi
l &
c
on
ta
cts
Te
st v
ol
ta
ge
Re
pl
ac
e t
he
st
eppi
ng
m
ot
or
Ch
ec
k r
es
ist
an
ce w
ith
m
ul
tim
et
er
Ch
ec
k r
es
ist
an
ce w
ith
m
ul
tim
et
er
Electrical Circuit