Basic of automatic voltage regulator

13/08/2011 by 30 Comments

Basically the AVR or Automatic Voltage Regulators function for generator is to ensure voltage generated from power generator running smooth to maintain the stable voltage in specified limit. It can stabilize the voltage value when suddenly change of load for power supply demand.

If the generator running in parallel condition,the AVR can controlled the voltage that it produce to ensure of equal value for reactive load sharing.

For the big system of interconnected power distribution with parallel design,it must have a full controlled and transient stability particular must added for requirement to the Automatic Voltage regulator for generator. read more

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Battery systems

10/08/2011 by 2 Comments

Batteries is one of the common thing in our daily application.We used it for domestic and industrial application.It can stored the electricity energy to made our equipment function properly.

We need to choose the suitable type of battery system depend on our application and design to ensure it can operated with maximum capacity.It have in several type such as dry type and wet types with different ampere rating from low to high current capacity.

In the market now we can selected several type of system for battery can suit for our needed and design.Below i listed basic categories for battery system read more

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How calculate ampere for electric motor?

20/07/2011 by 56 Comments

Generally for electric motor size,it rated by horsepower (hp) or kilowatts (kW) unit.We can recognize the electric motor size when refer to their kilowatts or horsepower.So from power (kW/hp), how we can know the full load ampere for electric motor?

This time i want share about how to calculated the full load ampere (FLA) of electric motor from their power rated.It not difficult if we know the right formula to get the answer.From this calculation we only can estimate the value of full load ampere.

We cannot get the actual full load ampere because it depend on efficiency of motor.If electric motors have a higher efficiency rating,it will draw fewer amps, for example a 10 HP motor with a 60% efficiency rating will draw about 65 amps at 230 VAC compared to about 45 amps for a motor with a 80% rating. 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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Dual voltage motor

17/06/2011 by 15 Comments

If we take a look at electric motor nameplate,we can see the several important information and specification about electric motor.This time i want explain about dual voltage for power supply.

It is like a simple thing and not so important BUT if we make a mistake about electric motor voltage power supply,it can cause the winding damage and burn out.That why i would like to share about this information to avoid serious damage for electric motor.

The reason why motor manufacture design dual voltage is to make this motor available for any country used because every country have a different voltage value such as 200 VAC,600 VAC and 415 VAC.It also so for marketing strategy to increase their profit margin. read more

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Auto transformer

23/05/2011 by 2 Comments

This is a one from several types of transformer.It usually used for motor starter,we recognize it by name “auto transformer starter”.Basically design for auto transformer only have a single winding and provided with tap connection for step up or down.

It have magnetic core with single winding which common primary and secondary circuits.The primary connection is connected with main AC power supply and secondary connection is connected with load.

If the primary is the total winding and is connected to a supply and the secondary circuit is connected across only a portion of the winding,It mean this is for stepped down voltage. read more

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UPS batteries charging rates

18/05/2011 by 2 Comments

Basically charging rates for UPS batteries depend on type of batteries cell such as Lead-acid (Pb) or Nickel Cadmium (NiCd).This two types of batteries cell have a different method to charging up.

For Lead-acid (Pb) cells is used a ‘constant voltage’ method.It mean where the current varies as the state of charge changes.Different method for Nickel Cadmium (NiCd) cells,it  is used ‘constant current’ where the cell voltage varies as the state of charge changes.

When we try to charging batteries  from  Lead-acid (Pb) cells type,the basic process are from a constant voltage source the charging current starts high and slowly decreases to a constant value when the cells become fully charged.The constancy of the current is an approximate indication that the cells are fully charged. read more

Filed Under: Theory Tagged With: , , , , , , ,
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