Direct current braking(DB)
A dc voltage can be applied to the motor windings
in orde to lock the motor shaft and avoid overun
at low speeds.
There are two methods of activating the dc braking,
Outside which is through the intelligent input
terminals and inside which is automatically started
at a specific frequency.
Set item
DC braking selection
DC braking late time
DC braking frequency
Functin code
Data
0.00-60.00
Contents
Inside DC braking : invalid
Inside DC braking : valid
Unit : Hz
When the output reaches the set frequency and
Inside DC braking is valid, DC braking is started.
Unit : second
After DC braking time is reached, or DB terminal is ON,
the late time is a delay before DC braking is started.
Unit : %
Weak (Zero current)
Strong (0.4 to 55kW : Range is from 0 to 100%)
(75 to 132kW : Range is from 0 to 80%)
Unit : second
The DC braking is stopped after this time delay has ela-
psed. The time is tarted when the late time has elapsed.
Edge movement (Example 1-6-a)
Level movement (Example 1-6-b)
Unit : second
It is valid for inside DC braking.
When operating command is ON, DC current is started.
Unit : kHz(0.4 to 75kW)
Unit : kHz(90 to 160kW)
DC braking power
starting DC braking
power
DC braking time
DC braking edge/level
selection
Staring DC braking time
DC braking carrier
Frequency
A051
A052
A053
A054/A057
A055
A056
A058
A059
00
01
0.0-5.0
0.
100.(80.)
0.0-60.0
00
01
0.0-60.0
0.5-15
0.5-10
(1) DC braking carrier frequency
It is possible to alter the DC braking carrier frequency. Set DC braking carrier frequency with A059.
However, Maximum braking power level is automatically reduced by DC breaking carrier frequency as follows.
5.5 to 75kW are according to (i). 90kW to 160kW are according to (ii)
100
90
80
70
60
50
40
30
20
10
3 5 7 9 11 13 15
(75)
(46)
(34)
(22)
(10)
i) 5.5 to 75kW
Maximum
braking
ratio(%)
Direct braking carrier frequency(
kW)
100
90
80
70
60
50
40
30
20
10
3
5
7
9 10
ii) 90 to160kW
(60)
(40)
(20)
(10)
Maximum
braking
ratio(%)
Direct braking carrier frequency(
kW)
Direct braking power limiter
Relation code
A051:DC braking selectiond
A052:
A053:
A054:
A055:
DC braking frequency
DC braking late time
DC braking power
DC braking time
C001-C008: Intelligent input terminal
A056:DC braking edge/level
selection
A057:Starting
A053: Starting
A054:
DC braking power
DC braking time
DC carrier frequency
Chapter 4 Explanation of function
N300-P INSTRUCTION MANUAL
Summary of Contents for N300-P
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