Hitachi NES1-002LB, Quick Reference Manual

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Chapter 7 Explanation of Functions
7 - 41
7.5.22 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 0. to 100. (%)
"0" specifies the smallest force (zero current);
"100" specifies the largest force (rated current).
DC braking time for
deceleration
A055 0.0 to 10.0 (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 10.0 (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 2 to 15(kHz)
(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 5kHz are set as shown below. For detailed decreasing
ratio, "DC braking force limiter" is to be referred.
DC braking force limiter
Maximum
braking
force (%)
DC braking carrier frequency(kHz)
0
80
100
70
60
50
40
30
20
10
90
3 15 13 11 9 5 7
(75)
(46)
(34)
(22)
(10)