Fuji Electric FRENIC-HVAC User Manual page 482

Judgment on the life of DC link bus capacitor (Bit 4)
Whether the DC link bus capacitor has reached its life is judged by measuring the discharging
time after power OFF. The discharging time is determined by the capacitance of the DC link
bus capacitor and the load inside the inverter. Therefore, if the load inside the inverter
fluctuates significantly, the discharging time cannot be accurately measured, and as a result, it
may be mistakenly determined that the DC link bus capacitor has reached the end of its life.
To avoid such an error, you can disable the judgment based on the discharging time. (Even if
it is disabled, the judgment based on the "ON-time counting" while the voltage is applied to
the DC link bus capacitor is continued.)
 For details about the life prediction function, refer to H42.
Since load may fluctuate significantly in the following cases, disable the judgment on the life
during operation. During periodical maintenance, either conduct the measurement with the
judgment enabled under appropriate conditions or conduct the measurement under the
operating conditions matching the actual ones.
• Auxiliary input for control power is used.
• An option card is used.
• Another inverter or equipment such as a PWM converter is connected to terminals of the
DC link bus.
DC fan lock detection (Bit 5) (for UL open type-rated inverters of 150 HP or above,
NEMA/UL TYPE 1-rated ones of 60 HP or above, and NEMA/UL TYPE 12-rated ones of 15
HP or above)
The inverter contains an internal air circulation DC fan. When the inverter detects that the DC
fan is locked by a failure or other cause, you can select either continuing the inverter
operation or having the inverter enter into the alarm state.
Entering alarm state: The inverter issues the alarm OH1 and allows the motor to coast to a
stop.
Continuing operation: The inverter does not enter the alarm state and continues to run the
motor.
Note that, however, the inverter turns ON the OH and LIFE signals on the transistor output
terminals whenever the DC fan lock is detected regardless of your selection.
If the ON/OFF control of the cooling fan is enabled (H06 = 1), the cooling fan may
stop depending on the operating condition of the inverter. In this case, the DC fan
lock detection feature is considered normal (e.g., the cooling fan is normally
stopped by the stop fan command.) so that the inverter may turn OFF the LIFE or
OH signal output, or enable to cancel the alarm OH1, even if the internal air
circulation DC fan is locked due to a failure etc. (When you start the inverter in this
state, it automatically issues the run fan command. Then the inverter detects the DC
fan lock state, and turns ON the LIFE or OH output or enters the alarm OH1 state.)
Note that, operating the inverter with the DC fan being locked for a long time may shorten the
service life of electrolytic capacitors on the PCBs due to local high temperature inside the
inverter. Be sure to check with the LIFE signal etc., and replace the broken fan as soon as
possible.
NEMA/UL TYPE1/ UL TYPE 12 switch (Bit 7)
Switch this when changing the protection structure from NEMA/UL TYPE1 to NEMA/UL
TYPE12. With respect to protection coordination, a protection level which suits for NEMA/
UL TYPE12 is resulted.
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