Benefits of using a soft starter
Soft starters are a simple and economic method of controlling AC motors for fixed speed applications. Traditional methods of starting motors such as direct-on-line (DOL) or star-delta result in increased machine wear through rapid acceleration and very high peak currents. Soft starters solve this problem through controlling the acceleration and deceleration phases of operation.
Control Techniques’ Digistart family offers two levels of functionality to meet all your soft starter requirements.
Digistart CS is a compact soft starter for motors up to 110kW (200A). The Digistart CS offers comprehensive motor protection features and is quickly commissioned using simple rotary switches.
The Digistart CS is among the most compact constant current/current ramp soft starters available. The built in bypass contactor eliminates heat dissipation and energy losses by bridging out the power devices once the motor is at full speed. This eradicates the need for external bypass contactors saving panel space, simplifying installation and allowing the use of non-ventilated enclosures. Digistart CS units can be mounted side-by-side and are DIN rail mountable up to 60A. This is ideal where multiple soft starters are required such as in motor control centres.
Ease of use
Digistart CS is a digital soft starter that is configured by simple rotary switches. Commissioning is easy, allowing you to get your system up and running quickly.
Cost effective design
In addition to the space saving built-in bypass contactor, the Digistart CS allows the control voltage to be taken directly from the mains power. This means there is no need for an external power supply, thus reducing your costs and cubicle space.
Digistart IS is an intelligent soft starter offering
many advanced features for motors up to 800kW (1600A). These features include ‘Adaptive control’ which provides an unprecedented level of acceleration and deceleration control, and an intuitive plain language display for configuration.
Advanced motor control
Digistart IS provides industry leading motor control, featuring constant current, current ramp and adaptive control start methods. Adaptive control is an innovative control method that not only controls motor current but also acceleration. It allows the user to select between early, constant or late acceleration/deceleration depending upon the application requirements. Adaptive control then monitors motor performance by analysing each start and adjusting accordingly to maintain optimum control.
Adaptive control can benefit many applications. A principle example is pumping where it can be used to eliminate water hammer by allowing the engineer to select the most appropriate deceleration profile for the system.
Compact and flexible installation
The compact Digistart IS features an internal by-pass (on models up to 110kW [220A]), reducing space and costs through eliminating the need for external components. In addition, higher power units from 160kW (360A) allow the power connections to be configured on the top or bottom of the unit for both input and output, simplifying the cabling. Units can be mounted side-by-side to further reduce cabinet space.
Easy configuration and monitoring
The Digistart IS keypad has a multi-language graphical display, allowing you to easily set-up and monitor your soft starter. Start-up wizards guide the user through common application configurations and reduce commissioning time. The customisable display also provides real-time performance monitoring and time stamped event logs that can be used for maintenance and diagnostics, helping to improve plant availability.
Digistart IS has an in-built fire mode. This is used in HVAC applications to help protect building occupants in the case of fire by pressurising escape routes to maintain a smoke free environment. Activation of this feature disables the soft starter protection ensuring it continues to run for as long as possible.
Digistart IS’s powerthrough operation ensures the soft starter will continue to operate using 2 phases if one of the power devices is damaged. This allows you to keep your plant running whilst a long term fix is found.
The Digistart IS allows the motor to be connected either in-line (three wire) or using an inside delta configuration(six wire). Inside delta configuration increases the power of the soft starter, meaning a smaller unit can be used. This is a compact, cost efficient solution when replacing star/delta starters where existing wiring can be used.