Mitsubishi Electric PUHZ-P100VHA2 Service Manual page 51

<Abnormalities detected while unit is operating>
Error Code Abnormal points and detection method
High pressure (High-pressure switch
63H operated)
Abnormal if high-pressure switch 63H
operated ( ) during compressor operation.
*
* 4.15 MPa
63H: High-pressure switch
U1
(1302)
High discharging temperature
(1) Abnormal if discharge temperature
thermistor (TH4 or TH32) exceeds
125: or 110: continuously for
5 minutes.Abnormal if condenser/
evaporator temperature thermistor (TH5)
exceeds 40: during defrosting and
discharge temperature thermistor (TH4
or TH32) exceeds 110:.
(2) Abnormal if discharge super heat
(Cooling: TH4 – TH5 or TH32 – TH5 /
Heating: TH4 – TH6 or TH32 – TH6)
increases.
All the conditions in A or B are
detected simultaneously for 10 minutes
continuously after 6 minutes past from
compressor start-up (including the
thermostat indication or recovery from
U2
defrosting).
(1102)
<Condition A>
• Heating mode
• When discharge super heat is less
than 70 deg.
• When the TH6 temp is more than the
value obtained by TH7 – 5 deg.
• When the condensing temp of TH5 is
less than 35:.
<Condition B>
• During comp operation (Cooling and
Heating)
• When discharge super heat is less
than 80 deg in Cooling.
• When discharge super heat is less
than 90 deg in Heating.
• When condensing temp of TH6 is
more than –40:. (In Cooling only.)
TH4 : VHA2 , VHA3(R1)
(1)
TH32 : VHA3R2/R3, VHA4, YHA(R1/R2),
YHA2
OCH415F
Case
1 Short cycle of indoor unit
2 Clogged filter of indoor unit
3 Decreased airflow caused by
dirt of indoor fan
4 Dirt of indoor heat exchanger
5 Locked indoor fan motor
6 Malfunction of indoor fan motor
7 Defective operation of stop
valve (Not fully open)
8 Clogged or broken pipe
9 Locked outdoor fan motor
0 Malfunction of outdoor fan
motor
1 Short cycle of outdoor unit
2 Dirt of outdoor heat exchanger
3 Decreased airflow caused by
defective inspection of outside
temperature thermistor
(It detects lower temperature
than actual temperature.)
4 Disconnection or contact failure
of connector (63H) on outdoor
controller board
5 Disconnection or contact failure
of 63H connection
6 Defective outdoor controller
board
7 Defective action of linear
expansion valve
8 Malfunction of fan driving circuit
1 Over-heated compressor
operation caused by shortage
of refrigerant
2 Defective operation of stop
valve
3 Defective thermistor
4 Defective outdoor controller
board
5 Defective action of linear
expansion valve
51
Judgment and action
1~6 Check indoor unit and repair defect.
7 Check if stop valve is fully open.
8 Check piping and repair defect.
9~2 Check outdoor unit and repair defect.
3 Check the inspected temperature of outside
temperature thermistor on LED display.
(SW2 on A-Control Service Tool : Refer to
11-10.)
4~6 Turn the power off and check F5 is
displayed when the power is turned again.
When F5 is displayed, refer to "Judgment
and action" for F5.
7 Check linear expansion valve.
Refer to 11-6.
8 Replace outdoor controller board.
1 Check intake super heat.
Check leakage of refrigerant.
Charge additional refrigerant.
2 Check if stop valve is full open.
34 Turn the power off and check if U3 is
displayed when the power is turned on
again.
When U3 is displayed, refer to "Judgement
and action" for U3.
5 Check linear expansion valve.
Refer to 11-6.