Expert Engineers

Auto Transformer Starters are most popular electromechanical reduced voltage starting devices providing maximum starting torque and minimum starting current for large induction motors where availability of starting current is limited but a minimal starting torque is require. An induction motors draws 6 to 10 times of full load current while accelerating to full speed if directly connected to power supply. With autotransformer starters the reduced voltage applied to the motors results in lower current and high torque.

The auto transformer starters manufactured by us are comprise of run contactor, start contactor, star contactor, motor protection relay for protection against overload, single phase, reverse phase, phase imbalance, earth fault, lock rotor current, under/over voltage etc., dry/oil immersed auto  transformer, timers and other accessories.

To start the motor, first the star contactor is engaged followed by start contactor supplying reduced voltage through auto transformer limiting input current to stationary motor while accelerating. The motor continues to

Accelerate and after preset time of 8 to 12 seconds the star contactor is opened and momentarily even lower current is supplied by auto transformer winding acting like inductors connected in series with motor. The time is short, just enough to disconnect star contactor and engage run contactor to supply full voltage to the motor to accelerate to achieve full speed. At this point motor can work on full load and transformer is disengaged by opening start contactor.

A motor soft starter is a device used with AC electrical motors to temporarily reduce the load and torque in the power train and electric current surge of the motor during start-up. This reduces the mechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network, extending the lifespan of the system

The soft starter has the following features that prove best it as best solution for motor starting:-

·         Built-in by-pass

·         User friendly keypad with illuminated language neutral display and four button keypad

·         Coated circuit boards for reliable operation in harsh environment

·         Torque control for excellent control of pumps

·         Current limit, adjustable between 1.5 – 7 x Ie

·         Motor overload protection with classes 10A, 10, 20 and 30

·         Motor underload protection to detect pumps running dry

·         Locked rotor protection, detecting jammed pumps

·         Kick start to start jammed pumps or conveyor belts

·         Analog output showing operational current, 4 – 20 mA

·         Optional fieldbus communication using Profibus, Modbus, Devicenet or CANopen

·         Sophisticated algorithm eliminating the DC-component and thereby providing excellent starting performance

A motor soft starter is a device used with AC electrical motors to temporarily reduce the load and torque in the power train and electric current surge of the motor during start-up. This reduces the mechanical stress on the motor and shaft, as well as the electrodynamic stresses on the attached power cables and electrical distribution network, extending the lifespan of the system

The soft starter has the following features that prove best it as best solution for motor starting:-

· Built-in by-pass

· User friendly keypad with illuminated language neutral display and four button keypad

· Coated circuit boards for reliable operation in harsh environment

· Torque control for excellent control of pumps

· Current limit, adjustable between 1.5 – 7 x Ie

· Motor overload protection with classes 10A, 10, 20 and 30

· Motor underload protection to detect pumps running dry

· Locked rotor protection, detecting jammed pumps

· Kick start to start jammed pumps or conveyor belts

· Analog output showing operational current, 4 – 20 mA

· Optional fieldbus communication using Profibus, Modbus, Devicenet or CANopen

· Sophisticated algorithm eliminating the DC-component and thereby providing excellent starting performance

Variable Frequency Drives form an essential part of any manufacturing plant. Its continuous operation is necessary for maintaining a plant’s output, and any failure results in a chain reaction, effectively bringing the entire industry to a standstill.

Manufacturing plants are notorious for their harsh work environments, ranging from moisture to dirt to corrosion. Variable Frequency Drives (VFDs) may come in protective shells but still require protection from these elements as well as a comprehensive enclosure for all associated equipment, thus, making it imperative for a plant to have a VFD Control Panel.

Much like any other enclosure or control panel, a VFD Control Panel consists of an enclosure, VFDs and associated equipment like:

·         Harmonic filters.

·         Protection equipment like relays, circuit breaker and stabilizers.

·         A bypass control to keep the VFD running in all conditions.

·         PLC for advanced control.

·         Communication equipment such as Switches and Modems.

·         Temperature control equipment such as anti-condensation heater or air conditioner.

·         Motor starters.

A VFD Control Panel is used for four primary reasons such as:

1.) Power switching & protection

VFD panels usually host a circuit breaker or a relay that can trip in-case the input power line is struck by any fault such as short-circuit, overload, etc. This protects the drive as well as any equipment connected to the line.

2.) Adjustable speed

Usually, the VFD panel’s door has a frequency control potentiometer installed to transmit command signals to the motor as per the operator’s settings. A bypass switch is located nearby to allow functioning of the motors incase the VFD fails.

3.) Protection from Environment

This is one of the major concerns for any control engineer as manufacturing units are filled with moisture, dirt, etc. that can result in short-term as well as long-term issues. Most commonly chemical buildup on open-connections can result in reduced performance while dirt accumulation can lead to shorter lifespan for the drive.

4.) Visual Control

VFD panels aren’t deployed only for protection against harsh conditions. A number of field indicators are installed to gain real-time information about the drive’s power consumption, frequency and other diagnostic information that is essential for the operator. In addition, controls are embedded to allow the operator to shift the frequency or take precautionary action based on the monitored values.