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

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

Cooling method for transformer

07/05/2011 by 2 Comments

Why cooling system for transformer very important? The amount of heat from a transformer typically dissipated  is about 12.5 watts per square meter of surface area per degree C.It also can prolong the transformer life span if it running in normal temperature without exceed the maximum limit.

Normally transformer installed in special area or room for power distribution such as sub station or power room.The heat generated from transformer must be removed by circulate the air by ventilation or by the cooling system.

Commonly manufacture use a method of lettering is used to denote the form of cooling for a particular transformer.Four upper case letters are used.The first pair of letters are for the heat removal from the windings and core. read more

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

Transformer winding connection

04/05/2011 by 1 Comment

When we want to install the transformer for our project or any application and auto transformer stater,firstly we must know the transformer winding connection.If not it will cause the damage or serious injury when it install with wrong connection.

So how we can identify the transformer winding connection?Here i want share some tips how to identify the winding connection.This basic information can effected to our voltage supply and if not done i  proper way,it can cause serious damage to our application or equipment.

Commonly manufacture already setting their code or identification method using a letters and numbers.Below is a standard identification code for transformer winding connection for USA,UK and EUROPE :- read more

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

Three phase transformer winding

03/05/2011 by 7 Comments

In the market now,commonly it have three methods of three phase transformer winding such as a star, delta and zig-zag. Each method can be applied to either or both of the primary and secondary winding of transformer.

This connection must suitable with our output voltage for application and equipment.We should decide which connection is suitable and not effected when power supply energizes.

This 3 types of winding is used for different application and we need to identify a suitable condition to apply this types of transformer winding.This time i want shared some information about transformer winding. read more

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

Single phase capacitor sizing

21/03/2011 by 61 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

Filed Under: Electric Motor Tagged With: , , , , ,

Single phase capacitor

20/03/2011 by 1 Comment

Firstly let me describe about what is capacitor?This device is very common used in electronic and electric application.The main function is to stored and release electricity charge.

It charge and release depend on frequency ( Hz ) of our power supply.Normally around 50 until 60 times per second in alternating current system.

The construction of capacitor basically made from wound layers of metalized polypropylene (dielectric).The element is sealing in a plastic can with a suitable sealing material.

We can see a two metal plates insulated from each others.For oil filled type,it use a PCB`s as a coolant agent,but now almost capacitor is dry type. read more

Filed Under: Electric Motor Tagged With: , , , , , ,

Voltage transformer

29/01/2011 by 9 Comments

This device is very common used in electronic/electrical industry in the world.Start from small transformer for electronic equipment until big transformer for High voltage  power transmission.Transformer is important device in our life every day.

The main purpose of voltage Transformer is a changing or “transform” the value of voltage ( single or three phase ) .

It can step up the voltage value ; example : 110VAC step up to 240VAC ( For power supply usage )  or 11 kVAC step up to 33 kVAC ( for power transmission).

It also can step down the voltage value ; example : 240 VAC step down to 24 VAC ( For rectifier power supply) or 11 kVAC step down to 415 VAC ( For Consumer power supply ). read more

Filed Under: Automation Tagged With: , , , , , , , ,
« Previous Page
Next Page »