Determining electric motor load and efficiency

21/07/2012 by 1 Comment

As we known,the electric motor is the one of important equipment to drive the operation smoothly from beginning to end of product.

Electricity cost normally around 60% came from electric motor running.It become more worth if installed motors are oversized,low efficiency,under design,poor maintenance or mismatched.

So to know the actual motor performance, we need to determine electric motor load and their efficiency to eliminated all problems that can cause the high electricity cost and breakdown.

We need to collected several important data from our electric motor to made comparison and analysis about load and efficiency.

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Capacitor sizing for power factor correction

09/05/2011 by 20 Comments

Commonly method for power factor correction using the capacitor to generate reactive power ( kVAR ) to reduce apparent power ( kVA ) form inductive load.

This time i want share a simple method to sizing our capacitor to improve power factor for induction motor and utility electricity.This method also can use for capacitor bank sizing.

Power factor correction is the one of famous topic for all electrical person at around the world.Many discussion and debate about how to sizing the capacitor for power factor correction.

How to sizing capacitor for power factor correction?

To properly sizing the amount of capacitor (kVAR) required to correct the lagging power factor,we  must have three (3)  important of information below: read more

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Single phase capacitor sizing

21/03/2011 by 39 Comments

When install a motor using capacitor for starting or running methods,we must sizing the rated of capacitor suitable with motor to get correct starting torque and avoid winding from overheating and can cause a damage.

This is basically a question of motor design.There is no straightforward regular relationship between capacitance and the motor size in kW.

When replacing these capacitors, the capacitance value and voltage should be taken from the manufacturer’s plate on the motor or from the old capacitor.This must be correct within ±5% and is sometimes stipulated down to a fraction of a μF.The choice of a running capacitor is even more limited than with a starting capacitor. read more

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Single Phase AC Motor

13/09/2010 by 6 Comments

Basic principles of operation

Electromagnetic field generated from the stator does not rotate.It is a repeater between the poles as the poles alternating ac voltage changes polarity.

The induced voltage in the rotor is the result of magnetic induction, and then the magnetic field produced around the rotor.This field is opposite to the stator field (Len `z Law).

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Miniature Circuit Breaker

03/09/2010 by 67 Comments

What is Miniature Circuit Breaker?

MCB (Miniature Circuit Breaker ( BS 3871 ) is a mechanical device operate automatic operation designed to connect and disconnect the electrical circuit in the ordinary and extraordinary situation.Suitable for AC and DC voltage.It mean main function is to protected equipment or circuit from overload and short circuit.

The size of MCB is small and usually use for household appliance and domestic.Average fix ampere rating from 6 Amp up to 125 Amp. It can be reset back to the normal condition after trip but cannot adjusted ampere rating.It can be found for single phase 1ø and three phase 3ø voltage power supply.

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