Carrier VECTOR 1800 MT - Page 301

9-8
62-11039
INDICATION/
TROUBLE
POSSIBLE CAUSES
REFERENCE
SECTION
9.4.7 Abnormal Pressure
Condenser coil dirty 8.27
Condenser fan rotating backwards Check Wiring
H
i
g
h
d
i
s
c
h
a
r
g
e
p
r
e
s
s
u
r
e
Condenser fan inoperative Check
H
i
g
h
d
i
sc
h
arge pressure
Refrigerant overcharge or noncondensibles 8.10
Discharge service valve partially closed Open
Suction modulation valve malfunction 8.23
Low discharge pressure Compressor valves(s) worn or broken 8.14
Suction service valve partially closed Open
Filter-drier partially plugged 8.16
Low refrigerant charge 8.12
Expansion valve defective 9.4.11
L
o
w
s
u
c
t
i
o
n
p
r
e
s
s
u
r
e
No evaporator air flow or restricted air flow 9.4.10
L
ow suct
i
on pressure
Excessive frost on evaporator coil 9.4.6
Evaporator fan(s) rotating backwards 8.7.3
Discharge pressure regulator valve defective Replace
Suction modulation valve malfunction 8.23
King valve partially closed Open
H
i
g
h
s
u
c
t
i
o
n
p
r
e
s
s
u
r
e
Compressor valves(s) worn or broken 8.14
H
i
g
h
suct
i
on pressure
Compressor gasket(s) defective 8.14
Suction and discharge
p
ressures tend to e
q
ualize
Compressor valves defective 8.14
p
r
e
s
s
u
r
e
s
t
e
n
d
t
o
e
q
u
a
l
i
z
e
when unit is operating
Compressor gasket(s) defective 8.14
9.4.8 Abnormal Noise
Loose mounting bolts Tighten
Worn bearings 8.14
Compressor
Worn or broken valves 8.14
C
o
m
p
r
e
s
s
o
r
Liquid slugging 9.4.11
Insufficient oil 8.14.4
Loose or striking shroud Check
Condenser or evaporator fan
Bearings defective 8.7.3
C
o
n
d
e
n
s
e
r
o
r
e
v
a
p
o
r
a
t
o
r
f
a
n
Bent shaft 8.7.3
V-belt Cracked or worn replace
9.4.9 Control System Malfunction
Sensor defective 8.28
W
i
l
l
n
o
t
c
o
n
t
r
o
l
Relay(s) defective Check
W
i
l
l
no
t
con
t
ro
l
Microprocessor controller malfunction Check