Check code
1500
(U7)
Superheat due to low discharge temperature trouble
Abnormal points and detection methods
Causes and checkpoints
If the discharge superheat is continuously detected −15
°C
[−27°F](*) or less for
5 minutes even though the indoor LEV has minimum open pulse after the
compressor starts operating for 10 minutes.
LEV : Linear expansion valve
TH4 : Thermistor <Compressor>
63HS : High pressure sensor
*At this temperature, conditions for the abnormality detection will not be
satisfied if no abnormality is detected on either TH4 or 63HS.
1.
Disconnection or loose connection of TH4
2. Defective holder of TH4
3. Disconnection of LEV coil
4. Disconnection of LEV connector
5. LEV performance failure
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting any connectors, or replacing boards.
Diagnosis
Remedy
Chart 1 of 2
No
Yes
No
Yes
No
Yes
Is the TH4
wiring disconnected?
Is the resistance normal?
Is there any abnormality
such as half-disconnection or
breakage?
Connect the wiring properly.
Replace the TH4.
Connect the connector properly,
or replace the LEV.
Check the resistance of
TH4.
Check the connector contact and wiring of
the indoor LEV.
Disconnect the indoor LEV wiring to check
the resistance.
(disconnected)
(connected properly)
Continue to the next page.
temp. - resistance characteristic
0°C
700 kΩ
10°C
410 kΩ
20°C
250 kΩ
30°C
160 kΩ
40°C
104 kΩ
55
OCH668G
