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7-3
YES
YES
NO
Is PTC operating?
Incorrect motor load or
inadequate cooling.
Check the motor side.
Faulty inverter or error
due to noise, etc.
Contact Fuji Electric.
External thermal relay tripped
OH2
Is PTC level
H27 set correctly?
Is PTC MODE
H26 enabled?
YES
NO
NO
Change to regular
external circuit.
Is the external circuit
(including constants)
regular?
Set to correct
value.
NO
YES
(7) External thermal relay tripped
YES
NO
Connect a thermal
O/L relay externally.
Is the electronic thermal
O/L relay setting correct?
Set to the correct level
Is the load excessive?
Inverter unit
overload OLU
Motor overload
OL1, OL2
Do the characteristics
of the electronic thermal
O/L relay and motor
overload match?
NO
NO
YES
YES
Reduce the load or
increase inverter
capacity
Faulty inverter or error
due to noise, etc.
Contact Fuji Electric.
(8) Inverter unit overload and motor overload
NO
YES
NO
NO
Is the load excessive?
Reduce the load.
Is the cooling
fan rotating?
Replace the cooling fan.
Check the temperature of
the heatsink using the alarm
information displayed
on the keypad panel.
Remove obstacles.
Faulty detection
circuit on PCB.
Contact Fuji Electric.
Overtemperature
at inside air OH3
Does the heatsink
temperature indicate
YES
YES
YES
Faulty inverter or error
due to noise, etc.
Contact Fuji Electric.
YES
Is the ambient
temperature within
the specification?
Arrange peripheral
conditions to meet
the specification.
Overheating
at heatsink OH1
NO
NO
Is the cooling air
passage blocked?
(6) Overtemperature at inside air
and overheating at heatsink.
YES
Connect the alarm
signal contact.
Is the alarm function
of the external
equipment operating
correctly?
Faulty inverter or error
due to noise, etc.
Contact Fuji Electric.
YES
Remove the cause
of alarm function
activation.
NO
NO
Is data input to
the control terminals
THR-X1 to X9?
Are alarm signals from
external equipment
input to the terminals
and the CM?
NO
YES
YES(30HP or less)
no
NO
YES
YES
NO
YES
NO
NO
YES
YES
NO
NO
YES
NO
NO
YES
Overtemperature
at inside air OH3
Overheating
at heatsink OH1
Is between the control
terminals 13-11 closed?
Check the temperature of
the heatsink using the alarm
information displayed
on the keypad panel.
Remove the short circuit.
Check the keypad panel display.
Display limit or not?
30HP or less: 20 degrees C.
(40HP or more: 50 degrees C)
Is the cooling fan
for mixing inside air
rotating?
(
40HP or more
)
Is the peripheral
temperature of the
inverter –10 degrees C
or less ?
Is between the control
terminals 13-11 closed?
Faulty detection
circuit on PCB.
Contact Fuji Electric.
Make peripheral
temperature of the
inverter to meet
the specification.
Is the load excessive?
Reduce the load.
Replace the cooling fan.
Is the cooling
fan rotating?
Replace the cooling fan
for mixing inside air.
Is the cooling fan
for mixing inside air
rotating?
(
40HP or more
)
Remove obstacles.
Is the cooling ai
r
passage blocked?
Faulty inverter or error
due to noise, etc.
Contract Fuji Electric.
Is the ambient
temperature within
the specification ?
A
rrange peripheral
conditions to meet
the specification.
(6) Overtemperature at inside air
and overheating at heatsink.
YES(30HP or less)