Hitachi SJ Series, User Manual

Page: 315 / 786

12-13-8
Chapter 12
Inverter Function
12.13.5 Suppressing overvoltage with
braking resistor
• Overvoltage error is generated when the motor is
decelerated.
• An overvoltage error is generated due to
regenerative load.
• I want to use this function to quickly decelerate the
motor.
• I want to use this function for lowering.
• This is a function concerning braking circuit (BRD).
• This function is to consume the regenerative
energy from the motor as heat using the external
resistor.
Operation rate
The motor will trip when the operation rate
exceeds the use rate.
Operation Rate (%) =
×100
Parameters
Monitoring
• You can also use the optional BRD unit instead of
using the built-in braking circuit (BRD). If using the
BRD unit, no setting needs to be made.
• The BRD ON level is the level setting for the main
circuit DC smoothing capacitor inside the inverter. It
needs to be set to a value exceeding the input
voltage times
√
2.
• See the selection and wiring of regenerative
braking resistor for minimum resistance that can be
connected and BRD use rate for each model.
Item Parameter Data Description
Braking resistor
circuit (BRD) use
rate
[bA-60]
0.0~100.0(%)
*) The upper limit depends on
[bA-63]
If it is set to 0.0, the BRD function will not be
activated.
If the setting is other than 0.0, the motor will trip
when [dA-41] BRD load factor monitor exceeds
the BRD use rate.
Braking resistor
circuit (BRD)
selection
[bA-61]
00 Disabled
01 Enabled (Disable while being stopped)
02 Enabled (Enabled while being stopped)
Braking resistor
circuit (BRD) ON
level
[bA-62]
200 V class: 330.0 - 400.0 (V)
400 V class: 660.0 - 800.0 (V)
The ON level at which the BRD is activated.
Braking resistor
circuit (BRD)
resistance
[bA-63] Minimum resistance ~600 (
Ω
)
Setting the BRD resistance to be connected
automatically sets the maximum value for [bA-60].
Item Parameter Data Description
BRD load factor
monitor
[dA-41] 0.00~100.00(%)
The value in accordance with the BRD use
rate will be displayed.
Q
A
!
BRD
Operation
t2
ON ON ON
100 Seconds
t1 t3
(t1+t2+t3)
100 Seconds