Filter
Top Products
5-4T-309
CONDITION POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.9 C ONTROLLER MALFUNCTION
Defective Sensor 6.22
Defective wiring Check
Will not control
Fuse (F1, F2, F3) blown Replace
W
i
l
l
n
o
t
c
o
n
t
r
o
l
Stepper motor suction modulation valve circuit malfunction 6.20
Low refrigerant charge 6.7
5.10 NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW
E
v
a
p
o
r
a
t
o
r
c
o
i
l
b
l
o
c
k
e
d
Frost on coil 5.6
Evaporator coil blocked
Dirty coil 6.15
Evaporator fan motor internal protector open 6.17
N
o
o
r
p
a
r
t
i
a
l
e
v
a
p
o
r
a
t
o
r
a
i
r
f
l
o
w
Evaporator fan motor(s) defective 6.17
No or partial evaporator air flo
w
Evaporator fan(s) loose or defective 6.17
Evaporator fan contactor defective Replace
5.11 THERMOSTATIC EXPANSION VALVE MALFUNCTION
Low refrigerant charge 6.7.1
External equalizer line plugged Open
Wax, oil or dirt plugging valve or orifice Ice formation at
valve seat
6.14
Low suction pressure with high
s
p
e
r
h
e
a
t
Superheat not correct 6.7.1
superheat
Power assembly failure
Loss of element/bulb charge
6
1
4
Broken capillary
6.14
Foreign material in valve
H
i
h
i
i
h
l
Superheat setting too low 6.14
High suction pressure
w
ith lo
w
s
u
p
e
r
h
e
a
t
External equalizer line plugged Ice holding valve open Open
super
h
ea
t
Foreign material in valve 6.14
Liquid slugging in compressor
Pin and seat of expansion valve eroded or held open by for-
eign material
6
1
4
F
l
u
c
t
u
a
t
i
n
g
s
u
c
t
i
o
n
p
r
e
s
s
u
r
e
Improper bulb location or installation
6.14
Fluctuating suction pressure
Low superheat setting
5.12 AUTOTRANSFORMER MALFUNCTION
U
n
i
t
w
i
l
l
n
o
t
s
t
a
r
t
Circuit breaker (CB-1 or CB-2) tripped Check
Unit
w
ill not start
Power source not turned ON Check
5.13 WATER-COOLED CONDENSER OR WATER PRESSURE SWITCH
C
o
n
d
e
n
s
e
r
f
a
n
s
t
a
r
t
s
a
n
d
s
t
o
p
s
Water pressure switch malfunction C heck
Condenser fan starts and stops
Water supply interruption Check