Generator exitation

03/09/2011 by 11 Comments

What is the excitation?The main purpose of excitation system for generator is to supply the power source to the rotor field coil.Excitation system produce the field current and it controlled by the automatic voltage regulator (AVR).I already discuss about automatic voltage regulator on my last post.

This field current controller is important to ensure the generator running in the suitable voltage.It also controlled the value of current when generator connected to a large load.It will receive or delivery the required level for reactive power ( kVAr). read more

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Thermal model protection for Soft starter

25/08/2011 by 1 Comment

Motor protection is the one of important criteria that we must consider when design the application to avoid serious damage or injury.

Normally we used thermal overload relay to protect electric motor from overload current problem.But if we used soft starter to driven our motor application,the suitable types of protection is using the motor thermal model.

This types provide more precise protection for electric motor and it more accurate and efficient.It only available for high end motor protection relay for conventional starter. read more

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Electro-Mechanical star delta starter

06/08/2011 by 36 Comments

Star Delta starter is the most widely used application especially for Air-compressor and HVAC system.This starter used for 6 or 12 wire for motor terminal depend on electric motor that chosen for the application.

Basically this starter used 3 unit contactor,1 unit timer delay,1 unit overload relay and start/stop button to control the star delta motor.Around the world,it have many types of control circuit design for star delta.

It have different design and technique  for the control circuit but the main objective is same,to reduce starting inrush current.

For safety condition for the star delta control circuit,it include with interlock for star and delta sequence to avoid serious damage for electric motor.That mean during star sequence,contactor for delta cannot energize or vise versa. read more

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Types of Molded Case Circuit Breaker MCCB

02/08/2011 by 2 Comments

Before we make a decision to install Molded case circuit breaker for our application,firstly we need to know about types of MCCB.It important information that we must know to make sure our MCCB can functioning properly to protect our application from electrical failure.

As we know the main function of MCCB are to protect our electrical application from short circuit or earth leakage and overload current.Manufacture have a their own design and types to suit domestic and industrial application.

To make a right selected for MCCB,the key point is to know what is our application or system and what protection we needed to install.After that,we can know which one of MCCB types we need for our application. read more

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MCCB protection for induction motor

31/07/2011 by 3 Comments

Circuit breaker is the one of important protection device when installing of electrical induction motor.This time i want shared some information about the major parameter that we need consider when applying Molded case circuit breaker(MCCB) for electric motor.

If we not selected the right MCCB for our electric motor application,it will effected to the system and it not running smooth and achieve our expectation.It will cause a additional costing for upgrading and repairing jobs.

Basically it have three (3) particular for induction motor protection.It is overload,locked rotor and short circuit breaker.This point is very important to ensure our motor protection reliability when problem happen. read more

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How to install lug for electric cable?

14/07/2011 by 8 Comments

Cable termination is important when we install equipment,machine,induction motor,power supply distribution and many more.We use a cable lug to connect the electrical cable with terminal or busbar.

The right method to install cable lug is important to ensure the termination is perfect and tight to avoid sparking.It can cause the damage of cable or the equipment.This time i want share some information about how to install a lug for 240mm electric cable.

Please use the suitable crimping tools and correct cable lug  according electrical cable size.If not the crimping process will not perfect and it can cause a serious damage.Following video is one of example how to crimping cable lug for 240mm cable. read more

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Criteria for cable design

11/07/2011 by 4 Comments

Cable is a important thing in electrical engineering to transfer the power supply from distribution to end user or equipment.It must have a quality and durability to ensure it can stand for any condition and long life span.

Day by day,manufacture made the research and development to improved quality and design of cable suitable with new technology and different surrounding area.It also improved for more efficiency,low cost,heavy duty and environment friendly.

To make a proper design for electric cable,the major criteria to get electrical cable be the good design and high quality are 4 items following : read more

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