Fuji Electric FRENIC-HVAC User Manual page 22

● Commercial operation switching
Because the inverter is equipped with a commercial frequency start processing function for
switching commercial / inverter operation by external sequence, peripheral equipment
configuration can be simplified. The inverter is equipped with 2 types of commercial operation
switching sequences: Fuji standard and inverter alarm automatic commercial switching
sequence.
ELCB or
MCCB
Power
Commercial/inverter
● Operation signal trouble is also avoided by command loss detection function.
If the frequency signal connected to the inverter (0 - 10V, 4 - 20 mA, multiple stage speed
operation signal, communication, etc.) is blocked, the fact that frequency command has been
lost is output as a "command loss" signal. You can furthermore set output frequency for
command loss in advance, so the equipment can continue to operate even if the frequency
signal is cut off by mechanical vibration, etc.
loss detection
● Low torque detection also possible
If a problem such as fan belt breaking and load connected to the motor becomes exponentially
lighter all of a sudden, detects that torque has dropped and outputs it as an output signal.
Abnormal status of the equipment can be detected using this signal, so it can be utilized as
equipment maintenance information.
Torque computation
value
Low torque
detection level
FRENIC-HVAC
Built-in
On/Off
sequence
Analog
frequency
command
Command
[REF OFF]
Output
frequency
Power
Time
1-6
Regular frequency
setting
Time
Broken
belt!
Transistor output