Hitachi SJ700-4000HFU2

Chapter 4 Explanation of Functions
4-20
4.2.19 DC braking (DB) setting
The DC braking function allows you to apply DC braking to the motor
according to the load on the motor.
You can control DC braking in two ways: the external control through
signal input to intelligent input terminals and the internal control to be
performed automatically when the motor is started and stopped.
Note that the motor cannot be stopped by DC braking if the load on
the motor produces a large moment of inertia.
Item
Function code
Data or range of data
Description
DC braking enable
A051
00
Internal DC braking is disabled.
01
Internal DC braking is enabled.
02
Internal DC braking is enabled. (The braking
operates only with the set braking frequency.)
DC braking
frequency setting
A052
0.00 to 60.00 (Hz)
With internal DC braking enabled, DC braking is
started when the output frequency reaches the
set braking frequency.
DC braking wait
time
A053
0.0 to 5.0 (s)
The DC braking wait time specifies the delay in
starting DC braking after the set braking time
has elapsed or the DB terminal has been turned
on.
DC braking force
during deceleration/
DC braking force for
starting
A054/
A057
CT mode :
0. to 100. (%)<0. to 80.(%)>
VT mode :
0. to 70. (%)<0. to 50.(%)>
"0" specifies the smallest force (zero current);
"100" specifies the largest force (rated current).
DC braking time for
deceleration
A055
0.0 to 60.0 (s)
This setting is valid for the external DC braking
in edge mode or for the internal DC braking.
DC braking/edge or
level detection for
[DB] input
A056
00
Edge mode (See examples 1-a to 6-a.)
01
Level mode (See examples 1-b to 6-b.)
DC braking time for
starting
A058
0.0 to 60.0 (s)
This setting is valid for the internal DC braking.
DC braking is started when the motor-start
command is input.
DC braking carrier
frequency setting
A059
CT mode :
0.5 to 15.0 (kHz)<0.5 to 10.0(kHz)>
VT mode :
0.5 to 12.0 (kHz)<0.5 to 8.0(kHz)>
Unit: kHz
(NOTE) <>:applied for 75 to 150kW
(1) Carrier frequency for DC braking
Use the DC braking carrier frequency setting (A059) to specify the carrier frequency for DC braking. But the raking
power reduced is reduced when 5Hz (up to 55kW) or 3Hz (75-150kW) are set as shown below. For detailed
decreasing ratio, "DC braking limiter" is to be referred.
DC braking force limiter(0.4-55kW) DC braking force limiter(75-150kW)
A051: DC braking enable
A052: DC braking frequency setting
A053: DC braking wait time
A054: DC braking force during deceleration
A055: DC braking time for deceleration
A056: DC braking/edge or level detection for
[DB] input
A057: DC braking force for starting
A058: DC braking time for starting
A059: DC braking carrier frequency setting
C001 to C008: Terminal [1] to [8] functions
Related code
DC braking carrier frequency(kHz)
Maximum braking
force (%)
DC braking carrier frequency(kHz)
(80)
VT mode
Maximum braking
force (%)
0
80
100
70
60
50
40
30
20
10
90
3
15
13
11
9
5
7
(70)
(46)
(34)
(22)
(10)
(58)
Maximum braking
force (%)
Maximum braking
force (%)
CT mode
0
80
100
70
60
50
40
30
20
10
90
3
15
13
11
9
5
7
(75)
(46)
(34)
(22)
(10)
CT mode
VT mode
0
80
100
70
60
50
40
30
20
10
90
10
9
7
(60)
(40)
(20)
(10)
5
3
0
80
100
70
60
50
40
30
20
10
90
10
9
7
(50)
(25)
(10)
5
3