Soft Braking - Emerson Digistart IS1x0043B series User Manual

Safety Rating Mechanical
Information Data Installation

10.6 Soft braking

For applications with high inertia and/or a variable load, the Digistart IS can be configured for soft braking.
In this application the Digistart IS is employed with forward run and braking contactors. When the Digistart IS receives a start signal
(pushbutton S1), it closes the forward run contactor (KM1) and controls the motor according to the programmed primary motor
settings.
When the Digistart IS receives a stop signal (pushbutton S2), it opens the forward run contactor (KM1) and closes the braking
contactor (KM2) after a delay of approximately 2-3 seconds (KT1). KA3 is also closed to activate the secondary motor settings,
which should be user programmed for the desired stopping performance characteristics.
When motor speed approaches zero, the zero speed detector (A2) stops the soft starter and opens the braking contactor (KM2).
Figure 10-6 Soft braking
6
CS H
7
DI1
Control voltage (model dependent)
1
Remote control inputs
2
Motor thermistor input
3
RTD/PT100 input
4
Relay outputs
5
Three-phase supply
6
Motor terminals
7
A2 Zero speed detector
F1 Semiconductor fuses (optional)
KA1 Run relay
KA2 Start relay
* The KT3 timer is only required if the zero speed detector is the type that performs a self-test upon power-up and momentarily
closes the output relay.
Parameter settings:
 Pr 3A Input A Function (terminals DI4, +24V)
 Select 'Motor Set Select' - assigns Input A for Motor set selection.
 Set starting performance characteristics using the primary motor set.
 Set braking performance characteristics using the secondary motor settings.
 Pr 4G Relay C Function
 Select 'Trip' - assigns Trip function to Relay Output C.
If the Digistart IS trips on supply frequency (Pr 16H Frequency) when the braking contactor KM2 opens, modify the
NOTE
frequency protection settings.
Digistart IS User Guide
Issue: 4
Electrical Keypad Quick Start
Installation and Commissioning
Status
C S L C S R TH2
TH1 PT3 PT4 PT5
1
3 4
2
+24V DI2 +24V DI3 +24V DI4 +24V
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Operation Programming Diagnostics
COM4
5
R LC4
KA3 Brake relay
KA4 Zero speed detector relay
KM1 Line contactor (Run)
KM2 Line contactor (Brake)
KT1 Run delay timer
KT2 Brake delay timer
KT3 Zero speed detector delay timer*
S1 Start contact
S2 Stop contact
S3 Reset contact
Application Technical Maintenance Options
Examples Data
1
79