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SiBE811001EB
Troubleshooting
CONVENI-PACK
212
8.4.33 Low Pressure Switch Failure or Operate
Error Code
H4
Applicable
Models
LRYEQ16AY1
Method of Error
Detection
Detect the continuity of the low pressure switch through the protection device circuit.
Error Decision
Conditions
When STD1 is stopped, there is no continuity of the low pressure switch for 10 minutes or more
When STD1 is running, the low pressure switch operates.
Operating pressure: 0.0MPa
(Return pressure: 0.06MPa)
Supposed
Causes
Defective low pressure switch
Broken wire of harness of low pressure switch
Low pressure switch connector connection failure
Defective compressor
Defective outdoor unit PCB
Broken lead wire
Four way valve (Y3R) action failure
Troubleshooting
Is the
protective HPS
connector connected to the
outdoor unit PCB
correctly?
Is there continuity in the
control or protection HPS?
Is there continuity in the lead
wire?
Stop the device for 10 minutes before
moving on to the next check.
YES
Is the four way valve
(Y3R) operate normally?
Replace the four way valve
(Y3R).
YES
Connect correctly.
Replace the outdoor unit main
PCB.
NO
NO
Replace the HPS with no
continuity.
∗
Resistance when normal: less
than 10
Ω
NO
YES
Replace the lead wire.
NO
YES
Caution
Be sure to turn off the power switch before connecting or disconnecting connectors, or parts may be damaged.