FE FRENIC-Multi series, Instruction Manual

Page: 134 / 196

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H11
Deceleration Mode
H11 specifies the deceleration mode to be applied when a run command is turned OFF.
Data for H11 Function
0 Normal deceleration
The inverter decelerates and stops the motor according to deceleration
commands specified by H07 (Acceleration/deceleration pattern), F08
(Deceleration time 1), and E11 (Deceleration time 2).
1 Coast-to-stop
The inverter imm
ertia of the motor and machine and their kinetic energy
ediately shuts down its output, so the motor stops
according to the in
losses.
When reducing the reference frequency, the inverter decelerates the motor
according to the deceleration commands even if H11 = 1 (Coast-to-stop).
2 H1
Instantaneous Overcurrent Limiting (Mode selection)
H12 spe
vercurrent rrent exceeds the instantaneous overcurrent limiting level.
e current limit processing, the inverter immediately turns off its output gate to
trol the output frequency.
cifies whether the inverter invokes the current limit processing or enters the
trip when its output cu o
Under th
suppress the further current increase and continues to con
Data for H12 Function
0
Disable
An overcurrent trip occurs at the instantaneous overcurrent limiting level.
1
Enable
The current limiting operation is effective.
oblem occurs when the motor torque temporarily drops during current limiting
an overcurrent trip (H12 = 0) and actuate a mechanical
If any pr
processing, it is necessary to cause
brake at the same time.
The similar function is the current limiter specified by F43 and F44. The current
limiter (F43/F44) implements the current control by software, so an operation delay
occurs. When you have enabled the current limiter (F43/F44), also enable the
instantaneous overcurrent limiting with H12 to obtain a quick response current
limiting.
Depending on the load, extremely short acceleration time may activate the current
limiting to suppress the increase of the inverter output frequency, causing the
system oscillation (hunting) or activating the inverter overvoltage trip (alarm
0 u
).
When specifying the acceleration time, therefore, you need to take into account
machinery characteristics and moment of inertia of the load.