Motor Starters And Some Of Types ...,

DOL And Star - Delta starters And Auto Transformer Starter ,

Introduction:
DOL ( Direct On Line ) , Star - Delta Starters and Auto Transformer Starters are one of Common Types of Starters Consistently  used in Industries and Domestically for Motors .

What is Starter?

The Electrical Energy is a Generated by Hydroelectric Power Plant ,  Thermal Power Plants, Solar Power Plants, Nuclear Power Plants, Gas Turbine Power Plant, Wind Power Plant, Diesel Power Plant are Some Of Power Generating Plants to Generate to full fill the Demands Of Domestic and Industries.

      From This Energy Multiple Industries Operating not only with lights , need to transform the Electrical Energy to Mechanical Energy and Thermal Energy. Motors are ( AC Or DC ) One of the Device which Converts Electrical Energy to Mechanical Energy ( To Rotary Motion ) .                                   Normally Motor need a Switching Device to Connect Electrical Energy, to  On and Off , Here is the Part Of Starters do Their Right Job. Receive Input as Electricity from Supply Bus and to Output to Motor when needed . Just Like a Switch to Motor from Supply Bus.

      Normally Motors too have Types. Types of Motor Chapter, will See in later Episode . So according to Switch Motors ( Kilowatt/Kw or Horse Power/HP ),  Types of Starters Play Different Rolls. DOL Stater Directly switch the Motor without any Delay with a High Inrush Current during Start of Motor.

     Recommended Kw/HP of Motor for DOL Starters Range is 3.7 to 5.5Kw / 5 to 7.5HP.  Above this range needed to minimize Inrush Current, Star to Delta Starters are used, This will also up to the range  11kw/15HP . Above this ranges Auto Transformer Starters do their Job.  

     In Previous Chapter, Discussed about, Variable Frequency Drives ( VFD ). 

Why is Starters Important ?

Motor Starters Are Important , Because Starters Protect Motors from Over Load, Under Voltage, Over Voltage and Single Phase Prevention.

Main Components / Features of Starters,

The Main Part Of Starter Is Contactor :

The Contactor is the Switch which Connects AC Supply to the Motor. Initially the Contactor is Normally Open with a Coil. When Supply Control Supply Given To Coil, The Contactor Switched to Normally Open Position to Normally Closed Position.  

Over Load Relay :

The Over Load Relay is Connected with Supply in series to Load . ( To Motor ). The Over Load Relay Consist of Current Setting Option with The Motors Rated Current + 20% Extra For Initial Inrush, when Motor Starting. If Current Limit Exceeds beyond limit The OLR ( Short form Of Over Load Relay ) deenergize the Contactor Coil, which disables the Control Signal.

Sigle Phase Preventer  and SD Timer Or Star Delta Delay Timer

The Name Itself Proves That If any Phase Failure, the Preventor Signals The Control signal To Protect Motor. The Preventer carries Four main jobs,                                                                                              1. Phase Failure .  

2. Phase Asymmetric . 

3. Over Voltage . 

4. Under Voltage  

The Star Delta Delay Timer used to switch between Star connection To Delta Connection , which Prevent High In Rush Current . 

Simply when starting, the Motor Starts at Low RPM with Star Connected Coil, after certain Interval of Delay switched to Delta Connection, This Device Is Used In Star To Delta Starters Only.   

Applications / Uses

The Application is,  in Domestic or Industries for Motors , The Starters are playing Main Roll to On and Off Motors.

Frequently Asked Questions (FAQ)

What is Starter used for?

Starter is Used for ON and OFF Motors .

Tags: Motor Starter, Star Delta Timer, VFD , Over Load Relay, Over Voltage Protection , Single Phase Preventer ,