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41

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Operation is stopped if rotation 
pulse signal is not input from the 
indoor fan motor for 1 minute.

Operation is stopped if rotation 
pulse signal from the indoor fan 
indicates low rpm (approximately 
300 rpm or less).

Expansion valve is closed if the 
temperature stays below 2˚C for 
4 minutes.

Compressor is stopped if a current 
approximately 55A or more flows in 
the power transistor module. 
Compressor is also stopped if the 
temperature of the power transistor 
module exceeds 100˚C

Lowers the operating frequency if 
the compressor AC current exceeds 
set value(    ). Stops the compressor 
if the current exceeds at minimum 
frequency.

Lowers the operating frequency if 
the temperature of the compressor 
thermistor (TH1) rises above 108˚C. 
Compressor is stopped if the 
thermistor stays above 108˚C for 
1 minute at minimum frequency.

Compressor is stopped if the 
compressor thermistor is above 
113˚C. (Or when TH1 shorts)

Lowers the operating frequency if 
the temperature of the outdoor heat 
exchanger rises above 56˚C during 
cooling. Stops the compressor if the
temperature stays above 56˚C for 
1 minute at minimum frequency

Indoor fan 
lock

Indoor fan 
rpm error

Indoor 
freezing 
prevention

DC over 
current

AC over 
current

Compressor 
overheat 
prevention 
control

Compressor 
high 
temperature 
error

Outdoor 
heat 
exchanger 
overheat 
prevention 
control

When indoor 
fan is rotating

When indoor 
fan is rotating
and stops

During cooling 
operation

During 
compressor 
operation

During 
compressor 
operation

During 
compressor 
operation

During 
compressor 
operation

During 
compressor 
operation

No limit

Opearation OFF

Automatically 
restarts when the 
heat exchanger 
temperature rises 
above the freezing 
prevention 
temperature 
(above 2˚C)

Automatically 
restarts after safety 
time(90 seconds)

Automatically 
restarts after safety 
time (90 seconds)

Automatically 
restarts after safety 
time (90 seconds)

Automatically 
restarts when 
thermistor (TH1) 
temperature falls 
below 99˚C 
(approximately 
30 minutes)

Automatically 
restarts after safety 
time (90 seconds)

Yes

No

No limit

No

No

8 times Yes

Yes

8 times

Yes

Yes

No limit

No

No

8 times Yes

Yes

No limit

No

No

Cooling MODE

Heating MODE

14.0A

14.0A

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11

12

Compressor ia stopped, if heat 
exchanger or outdoor thermistor 
shorts.
Close the expansion valve of the 
corresponding room, if some 
suction thermistor shorts.

Compressor is stopped, if 
compressor or heat exchanger or 
outdoor thermistor opens. 
Close the expansion valve of the 
corresponding room, if some 
suction thermistor shorts. opens. 

Compressor is stopped, if the 
operating frequency is above 70Hz 
and the compressor current is 
below 0.8A.

INDOOR
If open, while timer LED blinks, 
operation is continued.
If short, operation is continued.
OUTDOOR
Closes the expansion valve of the 
corresponding room if the 
outdoor unit does not receive a 
serial signal from one or more 
indoor unit for 30 seconds.
Compressor is stopped, if the 
outdoor unit does not receive a 
serial signal from all indoor units.

Compressor is stopped, and 
miswiring check operation ends. 

Thermistor 
short

Thermistor 
open

AC 
abnormal 
current

Serial signal 
error

Miswiring 
check error

When the room
is activated
turns ON and
the compressor
starts.

When the room 
turns ON 
and the 
compressor 
starts.

During 
compressor 
operation

During 
operation

During 
miswiring 
operation

Operation OFF

Operation OFF

Automatically 
restarts after safety 
time(90 seconds)

Automatically 
restarts as soon as 
the serial 
communication 
becomes possible.

Miswiring check 
operation will not
restart automatically.

1 time

Yes

Yes

1 time

Yes

Yes

8 times

Yes

Yes

No limit

Yes

Yes

8 times

Yes

Yes

13

Lowers the operating frequency if 
the temperature of any of indoor 
heat exchanger rises high 
temperature during heating. 
Stops the compressor if the 
temperature srays high for 1 minute
at minumum frequency.

Indoor heat
exchanger
overheat
prevention
control

During 
compressor 
operation

Automatically
restarts after
safety time.(90 sec.)

Automatically
restarts after
safety time.(90 sec.)

Automatically
restarts after
safety time.(90 sec.)

No limit

No

No

14

When a power factor module error
input is detected.

Power factor
module
(Active filter)
error

During 
compressor
operation

During 
compressor
operation

8 times

Yes

Yes

15

In the case that the feed back signal 
from the compressor is not input or
abnormal.

DC 
Compressor
rotation
error

8 times

Yes

Yes

43

: Blinks at 1-second intervals

: OFF

: ON

: Blinks 3 times at 0.1-second intervals

Indoor and outdoor unit 

completely stopped

Display by indoor unit operation lamp

Displayed in a pattern which comes on at  the 

same time as the timer lamp

4 seconds off

What to check, procedure

Display by 

outdoor 

unit lamp 

LED 

51 ~ 52

Diagnosis

Solution

Condition 

of indoor 

and 

outdoor 

unit

Normal

Twice

Temp. 

indicator

3 times

4 times

Power module(IPM) 

abnormality

Normal

1. Check the circuit in the power transistor module.

2. Is the outdoor fan revolving ?

1. Measure the resistance of thermistor TH2, TH3, TH4, TH5, 

    TH6, TH7 on the outdoor unit (see Figure 2).

1. Replace power transistor 

module

2. Replace power transistor the 

    outdoor fan motor or fan 

    capacitor.

Overheat of the 

comp-ressor error

(protector operating) 

or outdoor 

compressor 

thermistor TH1 short

1.Replace the outdoor thermistor 

assembly. (RH-HXA024JBZZ or 

    RH-HXA022JBZZ

1.Clear the discharge outlet.

2.Assure power supply voltage.

3.Refill to rated amount.

4.Replace the outdoor thermistor 

assembly. (RTHM-A022JBE0)

5.Replace the indoor thermistor 

assembl.

 (RH-HXA023JBZZ)

1. Is the discharge outlet of the outdoor unit clogged ?

2. Is the power supply voltage at least 207 V at full power 

operation ?

3. Check for refrigerant leaks at the tubing connections.

4. Measure the resistance of compressor thermistor TH1 on 

the outdoor unit (see Figure 2).

5. Measure the resistance of heat exchanger pipe thermistor 

TH2 on the indoor unit (see Figure 1).

Short circuit of the  

thermistor error

0.5

sec..

0.5

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sec.

1 time

Compressor lock

Overheat of the compressor

2 times

ON

OFF

ON

OFF

Self-diagnostic procedure using display mode

If the timer lamp and operation lamp blinks during operation, the problem can be diagnosed using the following table.  

Note: 1. The breakdown diagnossis can be diagnosed by the LED lamps by pushing the "AUX." button for 5 seconds 

             or more while operation stops.

              Normal : Only the timer lamp blinks. Error : Displayed by combined blinking of operation lamp and 

             timer lamp (below table).

         2. If the breaker is switched to "OFF", the self-diagnostic 

             memory will be erased.

         3. Example of outdoor unit LED 50 ~ 52 blinking :

44

: Blinks at 1-second intervals

: OFF

: ON

: Blinks 3 times at 0.1-second intervals

Indoor and outdoor unit 

completely stopped

Display by indoor unit operation lamp

Displayed in a pattern which comes on at  the 

same time as the timer lamp

4 seconds off

What to check, procedure

Display by 

outdoor 

unit lamp 

LED 

51 ~ 52

Diagnosis

Solution

Condition 

of indoor 

and 

outdoor 

unit

5 times

6 times

7 times

AC overcurrent error

1. Is the discharge outlet of the outdoor unit clogged ?

1. Clear the discharge outlet.

8 times

Abnormal wire check

1. Check the attached point CN8B of outdoor unit.

2. Measure the resistance value of thermistor TH5, TH6, TH7 

    of outdoor unit.

3. Check the expansion valve. (unit A, unit B, unit C)

4. 

Are four expansion valves connected by mistake ?

5. Check the wiring between units.

1.Reattach

2.Replace the outdoor thermistor 

assembly. (TH5, TH6, TH7)

3.Replace the outdoor control 

board assembly.

4. Reattach

5. Check the wiring between units.

6. Check the incorrect wiring.

 

 

(When connection between the   

units is wrong as follows)

1.Replace Power module (IPM)

2.Replace the outdoor Power 

supply P.W.B..

3.Rewire

1.Replace Power factor module 

(AF1)

1.Replace the outdoor control 

board assembly (Current 

transformer is broken.) 

1.Reattach.

2.

Replace the outdoor thermistor 

assembly. (RTHM-A022JBE0)

   or (RH-HXA024JBZZ or  

RH-HXA022JBZZ )

1. Can voltage be detected at the current transformer on the 

outdoor unit control board?

1. Are the connectors of the outdoor unit thermistors well   

attached ?

2. Measure the resistance of thermistors TH1, TH2, TH3, 

TH4, TH5, TH6, TH7 on the outdoor unit (see Figure 2).

AC abnormal current  

error

Open circuit of the 

thermistor error

A

B

Indoor unit

Outdoor unit

UNIT A

UNIT B

C

UNIT C

Terminal 

board

9 times

Rotation error of the

compressor

1. Check the voltage (18V) between BCN14  3   and   4

2. Check the compressor terminal and Power module terminal

    RED : S(COMP), U(IPM), WHITE : C(COMP), V(IPM), 

    ORANGE : R(COMP), W(IPM)

11 times

Power factor module

(AF1) error

1. Check the resistance value among the terminal of the 

    power factor module (L - and OUT -)