High voltage circuit breaker

30/01/2012 by Leave a Comment

As we know about circuit breaker is to protect electrical equipment from abnormal condition such as over load current or short circuit.For Low voltage circuit breaker,i already explain on my last post.Please read my post about miniature circuit breaker (MCB),molded case circuit breaker (MCCB) and residual current circuit breaker (RCCB) for more detail information.

For high voltage circuit breaker,the main contact mechanism normally designed with various method to avoid from damage and provide a better quenching around the contacts surface.The main purpose is to extinguishing any arcs formed as faster as possible. read more

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Fault protection

09/01/2012 by Leave a Comment

A new terminology for electrical currents now include all faults those between live conductors as well as earth or grounding faults.

If we not design our circuit protection properly followed standard guide,it can cause serious injury or death for human and equipment damage.

Fault current be determined at every relevant point. For small and medium installations with LV utility supplies, this is satisfied by determination of the fault currents at the incoming power supply. read more

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Relay Characteristics

08/01/2012 by 4 Comments

Relay manufactures design them for special applications to full fill industries needed and coupe with advanced technologies. This time i want share information about relays characteristics most often used in typical automation and instrumentation work.

As i explained in my last posted,basically principal for small DC and AC relays,sensitive relays, miniature and sealed relays, and some small power relays is common.

To get a suitable relay for our application,we should understand about basic relay characteristic and general specification about operation and relay design because manufacture designs many types of relay for different application.

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Types of Relay

07/01/2012 by Leave a Comment

In automation industries,relay is a common device used for control application.Basic operation of  electrical relay is a device that changes the state of a circuit in response to it being energized or de-energized by that or another circuit.

It function to open or close the circuit or contact and respond depend on signal that we gave it to the magnetic coil.It have normally open and normally close contact that we can choose when design the control circuit for our application.

For generally understanding,relay also may consider as a amplifier and controller.It only a small device in automation circuit but it have important roles to make our system running accordingly. 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 service a magnetic contactor?

27/07/2011 by 2 Comments

Magnetic contactor is a familiar device for control electrical motor,pump,capacitor and others.When it operate for long time,the main contact must be checked and cleaned due to sparking current during energized and de-energized.

We also must cleaning the dust or foreign material to avoid magnetic contactor mechanism stuck or cannot function properly.Normally i perform the services and cleaning jobs every 6 months.It depend on operating condition and last services.

During this services,we can checked the condition of contact point either is ok or not good.If the contact already worn or not in good shape,it need to replaced with a new one.It important to ensure the performance and operation is smooth and stable and current can flow through the contact without any problem. read more

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How to choose speed controllers for AC motor?

18/07/2011 by 2 Comments

Now around the world are using the speed controllers to control and drive their electric motor such as frequency inverter and soft starter.This speed control get a good reputation to reduce electricity cost and high efficiency to drive electric motor.

Speed controller is low maintenance and have a long life span.It easy to install and user friendly to setup and setting the parameter.

The wiring for power supply and control circuit is not so complicated like conventional motor control.This post i want share some basic aspects for choose the suitable ac motor speed controller that we must consider when to buy or install it on our application.I hope this information can be the basic guideline. read more

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