5.13 Soft Braking
For high inertia loads, the VLT
®
Soft Starter MCD 500 can be configured for soft braking.
In this application, the MCD 500 is employed with forward run and braking contactors. When the soft starter receives a start
signal (pushbutton S1), it closes the forward run contactor (K1) and controls the motor according to the programmed
primary motor settings.
When the soft starter receives a stop signal (pushbutton S2), it opens the forward run contactor (K1) and closes the braking
contactor (K2) after a delay of approximately 2–3 s (KT1). K12 is also closed to activate the secondary motor settings, which
are user-programmed for the wanted stopping performance characteristics.
When motor speed approaches zero, the external zero-speed sensor (A2) stops the soft starter and opens the braking
contactor (K2).
3
177HA526.12
6
5
6
4
2
3
1
K3T
K2
K10
K11
K12
K13
K1
M1
54 55
58
57
56
F1
K2
K1
K12
S2
K13
A2
K1T
K1T
K2T
K3T
K1
K2
K1 K2
S1 K10
K10
Y1
Y2
Y1
Y2
K10
K2T
4/T26/T3 E
1/L13/L2 5/L3
2/T1
33
34
A4 A5 A6
05 06
K12
K11
S3
53
1
Control voltage (model dependent)
K10
Run relay
2
Remote control inputs
K11
Start relay
3
Motor thermistor input (PTC only)
K12
Brake relay
4
Relay outputs
K13
Zero-speed detector relay
5
3-phase supply
K1
Line contactor (run)
6
Motor terminals
K2
Line contactor (brake)
A2
Zero-speed sensor
K1T
Run delay timer
S1
Start contact
K2T
Brake delay timer
S2
Stop contact
K3T
Zero-speed detector delay timer
S3
Reset contact
Illustration 5.15 Soft Braking Configuration
Parameter settings:
•
Parameter 3-3 Input A Function
-
Select
Motor Set Select
- assigns input A for motor set selection.
-
Set starting performance characteristics using the primary motor set (
parameter group 1 Primary Motor
Settings
).
Product Features
VLT
®
Soft Starter MCD 500
48
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MG17K602
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