Hitachi SJ Series User Manual page 315

Chapter 12
12.13.5 Suppressing overvoltage with
braking resistor
Q
• 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.
A
• 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.
t1
ON
BRD
Operation
100 Seconds
(t1+t2+t3)
Operation Rate (%) =
100 Seconds
Parameters
Item Parameter
Braking resistor
circuit (BRD) use
rate
Braking resistor
circuit (BRD)
selection
Braking resistor
circuit (BRD) ON
level
Braking resistor
circuit (BRD)
resistance
Monitoring
Item Parameter
BRD load factor
monitor
t2 t3
ON ON
×100
Data
0.0~100.0(%)
[bA-60] *) The upper limit depends on
[bA-63]
00
[bA-61] 01
02
200 V class: 330.0 - 400.0 (V)
[bA-62]
400 V class: 660.0 - 800.0 (V)
[bA-63] Minimum resistance ~600 (Ω)
Data
[dA-41] 0.00~100.00(%)
!
• 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.
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.
Disabled
Enabled (Disable while being stopped)
Enabled (Enabled while being stopped)
The ON level at which the BRD is activated.
Setting the BRD resistance to be connected
automatically sets the maximum value for [bA-60].
The value in accordance with the BRD use
rate will be displayed.
12-13-8
Inverter Function
Description
Description