Mitsubishi PEH series

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<Abnormality detected during unit operation: Indoor unit>
Abnormal-
ity display
P6
Meaning of abnormality display and
abnormality troubleshooting
Freezing/excessive rise protection
operation
1) Freezing protection
When the piping temperature re-
mains at –15 °C or lower for 3 min-
utes after 3 minutes have elapsed
since the compressor started, the
compressor enters the 6 minutes
restart prohibit mode and if the
piping temperature again remains
at –15 °C for 3 minutes within 16
minutes after 6 minutes restarting,
an abnormality is recognized.
2) Excessive rise protection
When a piping temperature rise
to 70 °C or higher is detected af-
ter the compressor starts, the
compressor enters the 6 minutes
restart prohibit mode. If a piping
temperature rise up to 70 °C or
higher is detected again within 10
minutes after 6 minutes restarting,
an abnormality is recognized.
Cause
<Cool and dry>
1 Filter is clogged (insufficient air flow).
2 Air duct short cycle.
3 Low load operation (low temperature)
exceeding allowable range.
4 Indoor fan motor faulty.
5 Outdoor fan control faulty (intermedi-
ate period, winter).
6 Refrigerant overcharged.
7 Refrigerant circuit faulty (clogged).
<Heat>
1 Filter clogged (insufficient air flow)
2 Air duct short cycle.
3 Overload operation (high temperature)
exceeding allowable range.
4 Indoor fan motor faulty.
5 Outdoor fan control faulty (intermedi-
ate period)
6 Refrigerant overcharged.
7 Refrigerant circuit faulty (clogged)
8 Outdoor unit bypass circuit faulty.
Judgment method and remedy
<Cool and dry>
1 Check filter for clogging.
2 Remove obstruction.
4 Check fan motor operation and winding
resistance.
5 Check outdoor fan motor operation.
67
Check refrigerant circuit operation.
<Heat>
1 Check filter for clogging.
2 Remove obstruction.
4 Check fan motor operation and winding
resistance.
5 Check outdoor fan motor operation.
6-8
Check refrigerant circuit operation.