Carrier 69NT40-511-310 - Evaporator Air Flow or Restricted Air Flow; Thermostatic Expansion Valve Malfunction; Autotransformer Malfunction; Water-Cooled Condenser or Water Pressure Switch

5-4T -296
CONDITION POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
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
E
vaporator co
i
l
b
l
oc
k
e
d
Dirty coil 6.15
Evaporator fan motor internal protector open 6.16
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 6.16
N
o or part
i
a
l
evaporator a
i
r
f
l
ow
Evaporator fan(s) loose or defective 6.16
Evaporator fan contactor defective Replace
5.11 THERMOSTATIC EXPANSION VALVE MALFUNCTION
Low refrigerant charge 6.7.1
External equalizer line plugged Open
W ax, oil or dirt plugging valve or orifice Ice formation at
valve seat
6.14
Low suction pressure with high
s
u
p
e
r
h
e
a
t
Superheat too high 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 with low
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
foreign material
6
1
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
F
l
uctuat
i
ng suct
i
on pressure
Low superheat setting
5.12 AUTOTRANSFORMER MALFUNCTION
Circuit breaker (CB-1 or CB-2) tripped Check
U
n
i
t
w
i
l
l
n
o
t
s
t
a
r
t
Autotransformer defective 6.19
U
n
i
tw
i
l
l
not start
Power source not turned ON Check
460 VAC power plug is not inserted into the receptacle 4.2.2
5.13 WATER-COOLED CONDENSER OR WATER PRESSURE SWITCH
H
i
g
h
d
i
s
c
h
a
r
g
e
p
r
e
s
s
u
r
e
Dirty coil
6
1
2
H
i
g
h
d
i
sc
h
arge pressure
Noncondensibles
6.12
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 Check
C
on
d
enser
f
an starts an
d
stops
W ater supply interruption Check
Downloaded from ManualsNet.com search engine