Medium voltage digital soft starters

Three-phase AC induction motors are commonly used in a wide variety of drive applications. Due to theirstarting characteristics, in many cases these motors cannot be connected directly to the power supply system. When starting Direct On Line (DOL) the motor can see a very high surge current reaching up to 6 times (and more…) the rated motor current. This excessive current puts stress on the supply system and the switchgear. Also, when starting DOL, a very high peak torque can occur, stressing the driven motor and the mechanical system including auxiliary power transmission parts (V-belt, gears, etc.). There are several methods for reducing the damaging effects of this excessive starting current. Conventional methods include reactors and autotransformers. But these methods only allow the voltage to be reduced in steps whereas a soft starter provides step-free acceleration of the drive system by continuously increasing the voltage over a selected period of time. This approach to starting minimizes the effect of high inrush current on the supply system, the motor and the driven load.

Soft starters provide the following benefits:

• Reduced starting current, eliminates voltage drops and dips of the supply network
• Smoother acceleration of loads, eliminates process or product damage
• Extended lifetime of all mechanical components, e.g. eliminates gearbox damage and results in less maintenance & downtime
• Extended motor life
• Reduced maintenance and operating costs

The HRVS-DN soft starter represents a logical extension of the Emco Kimo soft starter product range into medium voltage applications. With HRVS-DN, Emco Kimo presents an innovative standard product that provides a flexible, low cost alternative to fixed speed (DOL) starting. Designed for use with standard medium voltage three-phase squirrel cage induction motors as well as synchronous motors, this high-performance digital soft starter ensures smooth acceleration and deceleration. HRVS-DN is available in all standard internationally recognized medium voltage ratings: 2.3kV, 3.3kV, 4.16kV, 6kV and 6.6kV, 10kV, 11kV, 13.2kV, 13.8kV and 15kV. The standard current output range capability is from 200kW to 27MW.

HRVS-DN is designed and built to meet international standards including:
• IEC • EN • DIN VDE • NEMA • UL/CUL • IEEE

Complete Cabinet
The HRVS-DN soft starters are manufactured at the highest quality level. The entire design, production and delivery process, (i.e. construction, manufacturing, order processing and logistics delivery center) have been certified DIN ISO 9001.2000. The enclosed versions of the HRVS-DN are provided as ready-to-connect cabinet enclosed type or - for OEM only - chassis type OEM kits are available for building into custom enclosures or other relevant equipment.

OEM Version.
3.2 How Soft Starters Work?
By using thyristors (SCRs) in a phase angle control mode, reduced voltage control can be achieved. Phase control makes it possible to gradually increase the motor terminal voltage from an initial set point up to the system supply voltage level. The related starting current and the starting torque can be optimally adjusted to the motor/load conditions.

                In addition, the Emco Kimo HRVS-DN soft starters provide the “soft stopping” function as a standard feature. Similar to the reduced voltage start, a stop command gradually reduces the motor voltage over time until the motor stops. Abrupt stopping is avoided, a specific advantage in pumping applications to prevent the damaging effects of water hammer and on conveyor belts where the load may be damaged by an abrupt stop.

Main Features, Options and Advantages
Advantages at a Glance

• Complete line of 60-1,200A, 2,300-15,000V as standard products.
• Customized soft starters (consult the factory for details)
• Heavy duty, fully rated design
• Starting capacity of 400% of FLC for 30 seconds at a rated ambient temperature of 50°C
• Preparation for bypass - to maintain protection when bypass is closed
• Robust construction
• Superior starting & stopping characteristics
• Comprehensive motor protection package
• User friendly
• Unique protection for corrosive environments
• Generator ready - auto frequency tracking
• Sustains variations of 45-65Hz while starting

Unique built in optional features including:

• Motor insulation tester
• RS 485 comm. Modbus / Profibus
• Analog output
• Relay PCB for comm. control
• Tacho feedback
• Multi-start (standard)and Multi-soft stop (optional) capability
• Synchronous motor excitation system control
• Remote display

Standard Ratings

• 2.3kV, 4.16kV, 6kV, 6.6kV, 10kV,11kV,
• 13.2kV, 13.8kV, 15kV

Starting & Stopping

• Soft start & soft stop
• Current limit
• Pump control program
• Torque and current control for optimized starting & stopping process
• Dual adjustments - two starting & stopping
• characteristics
• Advanced pulse start
• Linear acceleration

Motor & Starter Protection

• Too many starts
• Long start time (stall)
• Shear-pin
• Electronic overload with selectable curves according to IEC classes or NEMA classes.
• Under current with adjustable delay
• Unbalance current with adjustable delay
• Ground fault with adjustable delay
• Phase loss & phase sequence
• Under, over & no voltage
• Load loss (motor not connected)
• Shorted SCR
• Starter over-temperature

Displays LCD & LEDs
Illuminated LCD - 2 lines x 16 characters

• Selectable languages: English, German, French and Spanish (Chinese and Russian - optional)
• Two display modes for basic and advanced applications
• Friendly operation with default parameters
• Eight LEDs for quick operational status
• Statistical data including:
• Total run time
• Total number of starts
• Total number of trips
• Last start current
• Last start time
• Last 10 trips with time stamp
• Current at trip

Unique Built-in Options
Analog output, related to the motor’s current, programmable as 0-10VDC, 4-20mA, 0-20mA or related to the motor’s rated power. Motor insulation test - a unique feature for submersible pumps, motors installed in harsh environments, etc The system measures motor insulation when motor is not running.

Two programmable levels are available:

• Alarm level, adjustable 0.2-5 Mohm
• Start disable level, adjustable 0.2-5Mohm, preventing starting when insulation is below acceptable levels
• Special tacho feedback circuitry
• Modbus RTU - enables setting, control & supervision
• Profibus DP – enables setting, control & supervision
• Relay PCB – enables starting the application when  the soft starter is installed in a cabinet via communication, and to control the excitation system of a synchronous motor
• Remote display allows the panel builder to mount the keypad of the HRVS-DN in a remote location of the Control Module. A standard length of 1.5m cable length is supplied
• Multi-soft stop special software allows to soft stop motors when a multi-start application is applied.

Unique external options

• Customized tailor-made design of a cabinet
• Advanced motor protection MPS-3000
• Digital multi-meter for advanced measurement capabilities - DPM-10
• Motor Insulation Protection – MIP-6 for advanced tracking of motor insulation level over more than 20 years
• Line and Bypass Contactors/VCBs
• Fuses and disconnectors
• Capacitors for power factor correction

Auxiliary relays
Three standard programmable relays (each relay
with one C.O. 8A, 220VAC contacts)

Immediate with adjustable on and off delays (can be dedicated for too many starts pre-alarm relay)

End of Acceleration, with adjustable on delay

Fault, programmable as fault or fault-fail safe operation. Low motor insulation alarm (optional relay)

Applications - Industrial

• Pumps
• Hydraulic systems
• Fans and blowers
• Compressors
• Conveyors

Applications - Marine & Offshore

• Water, ballast and fire-fighting pumps
• Refrigeration chillers and compressors
• Hydraulic pumps and power packs
• Thrusters
• Main propulsion motors

Customer references:

• Larsen and Toubro Ltd.
• Siemens Ltd.
• ABB Ltd.
• Cairn Energy Ltd.
• ONGC Ltd.

Kimo Electronics India Pvt. Ltd., is an ISO9000 Certfied Manufacturer, engaged in the manufacture, sales and marketing of soft starters in India and Asia for the last 20 years.  More then 8,000 Soft Starters have been installed and sold by Kimo Electronics in India alone.

Kimo Electronics Pvt. Ltd.
5/6 Magnum Opus Plaza, Shanthi Nagar,
Vakola, Mumbai 400055.
Tel. 91-222-6651771,2,4,5,6,7
Email: sales@emcoinfo.com