:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
20
Table 12 — Error Diagnosis and Troubleshooting without Error Codes
FIELD MAINTENANCE
REFRIGERANT
CIRCUIT
OTHERS
Possible causes of trouble
Compr
essor
stuck
Sho
rtage of r
efriger
ant
Res
tri
cted li
qui
d line
D
irt
y air filter
D
irt
y evapor
ator coil
In
suf
ficient air thr
ough evapor
ator coil
Overcharg
e of refr
ige
rant
D
irt
y or
partially
blocked condenser
Air or
in
compr
essible
gas in re
frigerant cycle
Sho
rt cycling of conden
sing air
H
igh t
emperatur
e condensing
medium
In
suf
ficient condensin
g mediu
m
Br
oke
n compr
essor
inte
rnal parts
In
ef
ficient compr
essor
Ex
p
ans
io
n v
al
ve
o
b
st
ru
ct
ed
Expansio
n valve or capill
ary tube closed
completely
L
eaking pow
er element on e
xpansion valve
Poo
r installation
of feeler bulb
H
eavy load condition
L
oosen
hold
down bolts and / or
Shipping plates remain attached
Poo
r choices of capacity
C
ontact of piping
with o
ther piping or exter
nal p
late
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 soon 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
Rep
lace the compre
ssor
Leak test
Rep
lace restr
icted par
t
Clean or
replace
Clean coil
Che
ck fan
Cha
nge charged r
efrigera
nt volume
Clean condenser
or re
move o
bstacle
Purg
e, evacuate
and rechar
ge
Remo
ve ob
str
uction to air f
low
Remo
ve ob
str
uction in air or
water flow
Remo
ve ob
str
uction in air or
water flow
Repl
ace compr
essor
Te
st
compr
essor
ef
ficiency
Rep
lace valve
Rep
lace valve
Rep
lace valve
F
ix feeler bulb
Che
ck heat load
T
ighte
n bolt
s or
screw
s
Remo
ve the
m
Cho
ose
AC of lager
cap
acity or add th
e number
of
AC
Rectify p
iping so as not to cont
act each other o
r with external
plate
