Battery systems

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

How calculate ampere for electric motor?

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

Criteria for cable design

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

Dual voltage motor

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

Auto transformer

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

UPS batteries charging rates

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

Battery for UPS

For uninterrupted power supply ( UPS ),the important component is a battery unit for UPS.The battery are used to store DC energy which is later used to supply a block of energy to a load,often in the form of a high current for a short time example to charge mechanism springs in switch gear,fire fighting system,emergency lighting, emergency instrumentation power for control panels and control devices and starter motors on engines generator.

Battery for UPS  must in good condition and well maintain to ensure it can operating in full capacity when it needed.If the battery failure during interruption of power supply,it can cause serious damage and high cost for operation recovery.

Types of battery

Normally for industry used applications are invariable of two kinds of battery,It have a advantage and disadvantage depend on our application :

1) Lead-acid (Pb).

2) Nickel-cadmium (NiCd).

A battery consists of a number of cells connected in series. The series connection is necessary to create sufficient load voltage. Each cell has a low voltage which is peculiar to the type of cell and independent of the current and rating of the cell. The cell voltages are shown in Table 17.1.

 

How to recharge the batteries for UPS?

The maximum cell voltages during charging should not exceed 2.7 volts per cell for Pb cells and 1.85 volts per cell for NiCd cells.Suppose a nominal voltage of 110 DC is required then at least 54 Pb cells or 89 NiCd cells would be required.The size of a battery is defined as its ampere-hour capacity, since capacity is related to charge (Q) which equals current (I ) × time (T ).

 

If there is a total failure from the main supply then it will usually be necessary to maintain the continuous current for 4 hours so that the state of the plant will be known during the failure. During this time it would be expected that the main supply would be restored.

Hence the 4 hours can be used as the operating cycle of the battery in the event that the charger is unable to supply current.

For the battery storage and compartment it may be installed in several ways.Example it can install integral with the charger, in a separate cubicle or on open racks.

The choice usually depends upon the physical size of the complete battery.If we plan to used a large battery,it are more suited to an open rack installation.