ERROR DIAGNOSIS AND TROUBLESHOOTING WITHOUT ERROR CODE (continued)
Field
Maintenance
Possible
Blown fuse
causes
Power failure
or varistor
connections
of trouble
Unit will not start
☆
☆
Compressor will
not start however
the fan runs
Compressor and
condenser
(outdoor) fan
will not start
Evaporator
(indoor)
fan will not start
Condenser
(outdoor) fan
will not start
Unit runs but
shortly stops
Compress or 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 /
Inspect fuse
Test voltage
connections -
remedy
type & size
Table 19 — Field Maintenance
Faulty
Loose
Shorted or
Safety device
thermostat/
broken wires
opens
room temp
sensor
☆
☆
☆
☆
☆
☆
☆
☆
☆
☆
☆
☆
☆
Test continuity
Inspect
Test continuity
Test circuits
of thermostat /
of safety
with tester
sensor &
tighten
device
wiring
Electrical Circuit
Faulty
Wrong setting
Faulty
Shorted or
magnetic
place of temp
transformer
open capacitor
contact for
sensor
compressor
☆
☆
☆
☆
☆
Place the
Check control
Check
Test continuity
temp. sensor
circuit with
capacitor with
of coil &
at the central
tester
tester
contacts
of air inlet grille
Faulty
Faulty
magnetic
Low voltage
stepping motor
contact for fan
☆
☆
☆
☆
☆
☆
☆
☆
☆
Test continuity
Replace the
of coil &
Test voltage
stepping motor
contacts
Shorted or
Shorted or
grounded
grounded fan
compressor
motor
☆
☆
☆
Check
Check
resistance with
resistance with
Megger tester
Megger tester