Unit Independently; General Troubleshooting Chart - IVT 12KHR-N Service Manual

12KHR-N
[4] HOW TO OPERATE THE OUTDOOR UNIT INDEPENDENTLY
1. Cooling in 40 Hz fixed mode
To operate the outdoor unit independently, short-circuit the sections indicated by arrows in the diagram below with an adapter, and apply 220-240
VAC between (1) and (N) on the terminal board of the outdoor unit. This allows the outdoor unit to be operated in cooling mode independently.
(Do not operate the outdoor unit in this condition for an extended period of time.)
C10

[5] GENERAL TROUBLESHOOTING CHART

1. Indoor unit does not turn on
Main cause
Cracked PWB.
(Cracked pattern)
Open-circuit in FU1
(250 V, 3.15 A)
2. Indoor unit fan does not operate
Main cause
Open-circuit in heat exchanger
thermistor (TH2) (in heating oper-
ation)
Disconnected heat exchanger
thermistor (TH2) (in heating oper-
ation)
3. Indoor unit fan speed does not change
Main cause
Remote control is not designed to
allow fan speed change in several
operation mode.
4. Remote control signal is not received
Main cause
Batteries at end of service life.
Batteries installed incorrectly.
Lighting fixture is too close, or
Fluorescent lamp is flickering in
the room.
Sevick light (Hitachi) is used in
the room.
Operating position/angle are
inappropriate.
Open-circuit or short-circuit in wir-
ing of light receiving section.
Light receiving unit is defective
(L2)
C9
Inspection method
Check visually.
Check melting of FU1.
Inspection method
Measure thermistor resistance
(dismount for check).
Inspect connector on PWB.
Check thermistor installation con-
dition.
Inspection method
Check operation mode.
Inspection method
Measure battery voltage.
Check battery direction.
Turn off light and check.
Check room lights.
Operate within range specified in
manual.
Check if wires of light receiving
section are caught.
Check signal receiving circuit
(measure voltage between termi-
nals 8 and 10, 9 and 10 of con-
nector CN17).
Connect with IC clip Connect with IC clip
Test mode cooling at 40 Hz Test mode cooling at 40 Hz
Normal value/condition
There should be no cracking in
PWB or pattern.
There should be no open-circuit.
Normal value/condition
-1
There should be no open-circuit
or faulty contact.
Thermistor should not be discon-
nected.
Normal value/condition
Fan speed should change except
during dehumidifying operation,
ventilation, light dehumidifying
operation, internally normal oper-
ation
Normal value/condition
2.5 V or higher (two batteries in
series connection)
As indicated on battery compart-
ment.
Signal should be received when
light is turned off.
Signal may not be received
sometimes due to effect of Sevick
light.
Signal should be received within
range specified in manual.
Wires of light receiving section
should not have any damage
caused by pinching.
Tester indicator should move
when signal is received.
3 – 6
Short-circuit negative terminal of
capacitor (C33) - and jumper
wire (JP16) using IC clip, etc.
Remedy
Replace PWB.
Replace PWB.
Remedy
Replace thermistor.
Replace thermistor.
Install correctly.
Remedy
Explain to user.
Remedy
Install new batteries.
Install batteries in indicated direc-
tion.
Change light position or install
new fluorescent lamp.
Replace light or change position.
Explain appropriate handling to
user.
Replace wires of light receiving
section.
Replace PWB.