Carrier 69NT40-511-310 - Troubleshooting; Unit will Not Start or Starts then Stops; Unit Operates Long or Continuously in Cooling

5-1
T -296
SECTION 5
TROUBLESHOOTING
CONDITION POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.1 UNIT WILL NOT START OR STARTS THEN STOPS
External power source OFF Turn on
N
o
p
o
w
e
r
t
o
u
n
i
t
Start-Stop switch OFF or defective Check
N
o power to un
i
t
Circuit breaker tripped or OFF Check
Autotransformer not connected 4.2.2
Circuit breaker OFF or defective Check
L
o
s
s
o
f
c
o
n
t
r
o
l
p
o
w
e
r
Control transformer defective Replace
L
oss o
f
contro
l
power
Fuse (F3) blown Check
Start-Stop switch OFF or defective Check
Evaporator fan motor internal protector open 6.16
Condenser fan motor internal protector open 6.11
Component(s) Not Operating
Compressor internal protector open 6.8
C
o
m
p
o
n
e
n
t
(
s
)
N
o
t
O
p
e
r
a
t
i
n
g
High pressure switch open 5.7
Heat termination thermostat open Replace
Low line voltage Check
Com
p
ressor hums
,
but does not
Single phasing Check
C
o
m
p
r
e
s
s
o
r
h
u
m
s
,
b
u
t
d
o
e
s
n
o
t
start
Shorted or grounded motor windings 6.8
Compressor seized 6.8
5.2 UNIT OPERATES LONG OR CONTINUOUSLY IN COOLING
C
o
n
t
a
i
n
e
r
Hot load (Failure to Pre--cool) Normal
C
onta
i
ner
Defective box insulation or air leak Repair
Shortage of refrigerant 6.7.1
Evaporator coil covered with ice 5.6
Evaporator coil plugged with debris 6.15
Evaporator fan(s) rotating backwards 6.15/6.16
Defective evaporator fan motor/capacitor 6.17
Air bypass around evaporator coil Check
Refrigeration System
Controller set too low Reset
Compressor service valves or liquid line shutoff valve par-
tially closed
Open valves
completely
Dirty condenser 6.10
Compressor worn 6.8
Current limit (function code Cd32) set to wrong value 3.3.5
Suction modulation valve malfunction 6.18
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