Symbol Diagnosis Diagnosis method
F93 Compressor
abnormal revolution
CU-2E:
When the rotation of the compressor is not synchronized with the control signal, the F93 diagnostic display is
stored in the memory, and operation stops. 3 minutes later, operation is restarted. This trouble display appears
when this happens on 4 occasions in a 20-minute period.
CU-3E/4E:
When a state in which the rotation of the compressor is not synchronized with the control signal has been
detected on 8 successive occasions, operation stops, and the trouble display appears.
<Diagnosis checkpoint>
1. To check whether the 2-way or 3-way valve has been left open by mistake, operation is performed for one
to several minutes after the compressor has started up, F93 is stored in the memory as the symptom, and
operation stops.
2. Check the inverter circuit (for open circuits) in the control P.C. Board: Check the IPM base current (6
locations) within 3 minutes after the power has been turned back on. As the symptom, F93 is stored in the
memory 30 seconds after the compressor has started up, and operation stops. The trouble display
appears after 4 restarts.
3. Check for broken wires (open circuits) in the compressor winding: Approximately 1 ohm under normal
conditions for each phase (same symptom as in 2.)
F95 Outdoor high
pressure protection
CU-2E only
When the temperature of the outdoor unit heat exchanger temperature sensor exceeds 62 °C, the F95
diagnostic symbol is stored in the memory, and operation stops. 13 minutes later, operation is restarted at a
temperature below 48 °C. This trouble display appears when this happens on 4 occasions in a 20-minute
period.
<Diagnosis checkpoint>
1. Check the outdoor unit heat exchanger temperature sensor (check for changes in its characteristics and
check its resistance).
2. Check whether something is interfering with the dissipation of the heat outdoors.
F96 Power transistor
module or
compressor
overheating
(CU-2E)
CU-2E:
Heating is detected inside the IPM which shuts itself off, the F96 diagnostic symbol is stored in the memory,
and operation stops. 3 minutes later, operation is restarted. The trouble display appears when this happens on
4 occasions in a 30-minute period.
CU-3E/4E:
When this trouble is detected from the electrical parts radiation fin temperature sensor and OLP output during
operation, operation stops, and it is restarted 3 minutes later. If the trouble occurs on 4 occasions, operation
stops, and the trouble display appears.
<Diagnosis checkpoint>
1. Something may be interfering with the dissipation of the heat outdoors or the outdoor unit fan may be
defective. (The outdoor unit fan is not running.)
2. Defective IPM (outdoor unit control P.C. Board)
3. Gas leaks. 2-way or 3-way valve is not opened.
Compressor high
discharge
temperature
(CU-3E/4E)
F97 Compressor high
discharge
temperature
When the temperature of the compressor temperature sensor exceeds 112 to 120 °C, the F97 diagnostic
symbol is stored in the memory, and operation steps. Two minutes later, operation is restarted at a
temperature below 107 to 110 °C.
CU-2E: The trouble display appears and operation stops when this happens on 3 occasions in a 30-minute
period.
CU-3E/4E: This trouble display appears and operation stops when this happens on 6 occasions (it is cleared
when the operation is normal for 20 minutes).
<Diagnosis checkpoint>
1. Check the refrigerating cycle: Gas may be leaking (the amount of refrigerant is low). The stopping of the
outdoor unit from time to time is a symptom of this trouble.
2. When operation steps with this trouble display appearing, check the compressor temperature sensor
(check for changes in its characteristics and check its resistance).
3. Something may be interfering with the dissipation of the heat outdoors or the outdoor unit fan may be
defective. (The fan will not run because of an open circuit.)
(The protection function may be activated by an overload, and the F97 trouble display will remain stored
in the memory.)
F98 Total running current
protection
CU-2E:
When the total current exceeds the setting, the F98 diagnostic display is stored in the memory, and operation
stops. 3 minutes later, operation is restarted. The trouble display appears and operation stops when this
happens on 3 occasions in a 20-minute period.
CU-3E/4E:
When the total current exceeds the setting (17A to 20A), frequency control is started, and if it then exceeds the
setting, operation stops, and the trouble display appears.
<Diagnosis checkpoint>
1. Check the AC voltage at the outdoor unit terminal board during operation: The voltage drop must be within
5% of the voltage when operation has stopped (± 110% of rated voltage even during operation). If the
voltage drop exceeds 5% or if the voltage changes suddenly, inspect whether the power supply cord and
indoor/outdoor unit connection cables are too long or too small in diameter, etc.
2. heck whether something is interfering with the dissipation of the heat outdoors (during cooling operations):
Normally, the capacity is limited by the current so that the outdoor unit don’t stop, and the diagnostic
display does not appear.
85
CS-ME7CKPG / CS-ME10CKPG / CS-ME12CKPG / CS-ME14CKPG / CS-ME18CKPG / CU-2E15CBPG / CU-2E18CBPG / CU-3E23CBPG / CU-4E27CBPG
To Next Page
Loading...
Need help?
General
