Transformer oil testing

In this article we will discuss about the transformer oil testing and maintenance  of transformer.here we will discuss in detail about transformer oil testing.

Transformer oil testing 

conservators are so designed that the lower part acts as a sump in which impurities and sludge may collect. A valve is fitted at the lowest portion of the conservator for draining and sampling . the inside of the conservator  should be cleaned periodically.

Oil indicator glass should be kept clean so that oil level is clearly visible . Broken indicate glass should be replaced immediately. when conservator is taken for maintenance magnetic oil level indicator mechanism  should also be cleaned  and inspected for operation. float should be checked to see that there is no oil in the float.

Transformer oil testing and maintance of transformer

transformer oil testing

Silica gel breather

Breather should be inspected frequently especially in a situation where temperature and humidity changes are considerable and when transformer is subjected to fluctuating loads so as long as silica gell is in active stage. its clour is dark blue as it becomes saturated with moisture , its color changes to pale blue/pink when it should be reactivated.

Buchholz Relay

Routine operation and mechanical inspection tests should be caries out as recommended. during service. if gas is found to be collecting and giving alarm,the gas should  be tested and analysed to find out the portable nature of the fault.  Sometimes , it may be noticed that the gas collected is only air. the reason for  this may be that the  oil is releasing  absorbed air due to change in temperature. the absorbed air released on in initial period of six month can be identified to a great extent by a chemical analysis of gas.
Buchholz rely will also give alarm or trip the breaker due to oil level falling below the buchoholz rely . Isolating valve between the conservator and buchholz rely facilities removal buchholz rely for repairs / checking without lowering the oil level in conservator it should be ensured that isolate ring  valves of buchholz ely are kept fully open for  unhindered oil flow

Temperature indicators of transformers 

at each yearly maintenance inspection the level of oil in the pockets holding thermometer bulbs should be checked and the oil replenishment is required. the capillary tubing should be fastened down again if it has become loose. dial gases should be kept clean and if broken,replaced as soon as possible to prevent damage to the instrument. temperature indicators found reading incorrectly should be calibrated with standard thermometer immersed in hot water and  it found ,clean the pocket and refill with fresh oil and seal the ping properly. if armoring of capillary is exposed . then retyping must be done by PVC tape of good quality to prevent  further damage to the  armoring or capillary.
Bushings
porcelain insulators and connectors should be cleaned at convenient intervals and minutely examined for any cracks or other defects or narrow are difficult to detect, however they are likely to devoplop rapidly. all such bushing should be replaced. similarly all inside the oil communicating type bushing should be checked by unscrewing air release screws provided on bushing top. the cause  of any serious loss of oil should be investigated. in case  of any sign of oil leakage in the bushing he matter should be refereed to us.
External connections including earthing
all connections should be tight. if they appear blackened or corroded, unbolt the connection and clean down to the bright metal with emery paper. remark the connections and give it a heavy coating of grease. it is particularly that heavy current carrying connections should properly maintained.

Gaskets

check  the transformer for leakages periodically. the bolts should be tightened evenly around the joints to avoid uneven pressure. broken or leaking gaskets should be replaced as soon as possible.
Rollers
after the transformer has been in service for long period , rollers should examined carefully . they should be greased and rotated to see that they turn freely.

Faults and failures in transformer

Although failure in transformers is rare, faults do occur and the reason may be broadly classified as ;
1. failure in magnetic circuit
2. failure in electrical circuit.
3. failure in dielectric circuit
4. failure in structural and mechanical fittings. 

Difference between UPS and inverter

           
    In this article we learn about the difference between UPS and inverter. We will discuss in detail of the difference between UPS and inverter.
difference between ups and inverter ,difference between inverter and ups.

Difference between UPS and Inverter

      

                     Inverter

            UPS(union power supply)        

1. Inverter is the parts of UPS
UPS is the combination of rectifier and inverter, with battery.
2. Cost of Inverter is lower than UPS.
It is the basic difference between ups and inverter
UPS cost is much higher than inverter because it have more equipment than inverter.
3. Inverter is an electrical device which converts DC power into AC power.
The load will experience AC even though supply is DC such as batteries. The electricity can be at any desired voltage. It's usually set to home voltage for normal home appliances application.
UPS is a device which gives emergency power supply. UPS is like battery and it work like also inverter.
It gives AC power when the main power is not available. When main power is restored a rectifier supplies DC supply to recharge the batteries. 


 4. Inverter takes low voltage DC power and converts it to AC power Mains level AC voltage. For example 12V lead acid battery to 230V supply.

UPS first stores energy then releases when there is a power cut off or power supply not available then it provide power supply.
This is also a difference between UPS and inverter.
5. Inverter are generally convert DC (direct current) power into AC( alternating current) power.

It have a battery source and also have converter which converter AC power into DC power and DC power into AC power according to requirement.
When it became charge it converts AC power into DC power. So these are also the difference between ups and inverter.
6. The inverter alone uses less without DC power supply.
It can be used as battery, for emergency power supply.
It is an electronic gadget which converts AC into DC.
It is a device which is used for emergency power supply.
 7. An inverter is an internal block of a UPS.
In a UPS inverter are also available. We can simply say that ups can work of inverter.

Inverter does not work like power pack. Because it cannot store energy.
It is main difference between UPS and inverter.
8. Inverter is  used to support power supplies when there is black out
It is also used to support power supplies when there is black out.
9. it does not provide much protection .
It provides more protection than inverter.
10. it has changeover , in emergency it can changeover supply .
It has not changeover, it cannot changeover contact.

Hence it is the difference between UPS and inverter. If you will find any incorrect please comment below.
For knowing more about the diffrence between ups and inverter please must watch this video.


Difference between primary cell and secondary cell



In this article we will learn about the difference between primary cell and secondary cell. we will discus in detail that what is basic difference between primary cell and secondary cell.

difference between primary cell and secondary cell, basic difference between secondary cell and primary cell.


Difference between primary cell and secondary cell


                           Primary cell

                             Secondary cell

1. 
Primary cells are a type of batteries which are not easily recharged after use. Secondary cells are also a type of battery which is easily charge after use. Which means it is rechargeable.
It is discarded after a single use, But secondary cells are used over and over again. By recharge of battery.

2.  It is not disposable


It is disposable
3. Primary cells example, boys, toys, radio cell, and watch cells etc. which are use only one time. Simply we say that use and threw.  
Secondary cells example, automobile field battery, power source battery, power pack etc. which is recharge again and again according to requirement.
  4.  It is usually lack a free-flowing electrolyte; instead, they hold the electrolyte inside solid devices which called separators. Because they lack a significant quantity of liquid electrolyte, such batteries are often called dry cells..
When secondary cells have completely discharged then they can be recharged and used again. By pumping electric current through the cell in the opposite direction that it normally flows, for additional use cell can recharge.
5.   Primary cells life-cycle cost is low.

Secondary cells life-cycle cost is high than primary cells.   it is main difference between primary cell and secondary cell.
6. Primary cells initial cost is lower because it is use only one time .
Secondary cells initial cost is higher than primary cell. Because it is rechargeable.

7. Replacement readily available.
 In this type of cells , Replacements are not available .
8.  It is both type lighter and smaller thus traditionally more suitable for portable application. And longer service per charge and good.
Secondary cell is Traditionally less suited for portable applications, although recent advances in Lithium battery technology have led to the development of smaller/lighter secondary batteries.
It main difference between primary cell and secondary cell.

9. It is not suitable for high load and longer service.
secondary cell are suitable for heavy load and longer service


 hence it is the difference between primary cell and secondary cell. if you will found any incorrect in above please comment below in comment box.

For knowing more about the difference between primary cell and secondary cell you must watch this video.

Difference between fuse and circuit breaker

In this article we will discuss about the difference between fuse and circuit breaker.
Difference between fuse and circuit breaker

                      Fuse

                       Circuit breaker

1.   It has a Rated Current (IN), which is the maximum rated current before the breakdown. Rated Voltage is the minimum voltage at which the circuit will be open due to melting of the wire.
It has also a rated current but there are different ratings, according to relay setting we can change rating of circuit breaker.

2.   The  fuse is a circuit element that is a one-time use element,  simply we can say that fuse is a piece of wire which connect two conductor terminal and provide softy  from different fault, as like short circuit, earth fault , over current fault.
The circuit breaker is a electromagnetically device which is used for connecting to conductor terminal and provide safety,, basically it used for connecting two conductor and provide safety from different fault.
3.  It is not re settable,,, or one time use. Fuse is a device which use only one type it has not reset option because after occurring fault, it become melt.
 But circuit breaker is re settable, and it works on magnetic attraction. It have magnetic coil according to setting it work on different rating.

4.  The fuse is less costly than circuit breaker; it is only a conductor wire which uses to connect two conductor terminals.

The circuit breaker is more costly than fuse because it has different other component, as like rely.
Operation of fuse is inherently complete automatic.                                 Elaborate components such as relays are used for automatic action
5.  It performs both detection and interruption. It has not extra system for detection. It works both detection and interruption.

·         But circuit breaker performs only interruption, which means fault is detected by the rely system provide for this purpose.
6.  The operation of fuse is very less (0.002 sec). It is use for low rating and for less costly equipment.
The operation of circuit breaker is very fast. It has use for heavy and high costly equipment.
7.   It is has use for only protection from normal fault.  
It has use for different protection of different fault.


 Hence it is the basic difference between fuse and circuit breaker, if you will find any incorrect above please comment below in comment box.


For knowing more about the difference between fuse and circuit breaker you must watch this video.


Difference between electrical and electronics

In this article we will discuss about the  main difference between electrical and electronics. Will discuss in detail of main difference between electrical and electronics engineering.

difference between electrical and electronics, main difference between electronics and electrical

Difference between electrical and electronics.

                            Electrical
                                Electronic

1. In this field we studied about the utilization or application of flow of electrons.


It is the field of engineering in which we study about flow of charge (electron and holes).

2. This Technology is a field of engineering technology related to Electronics and Electrical Engineering which deals in transmission, generation & distribution of electrical energy and its application.


This technology is a field of engineering technology related to electrical and electronic engineering which deals , electronic itomes ,electronic device , digital equipment and its application.

3. The main difference between electrical and electronics equipment, take example of electrical appliances at your home like oven, fan work on AC.



For example tablets , mobile, computer , and other related equipment consider in electronic system.

4. In this engineering working voltage is very HIGH VOLTAGES and low constant frequency. For example 60HZ. And voltage is 220V, 440V.



In electronic engineering working voltage is low but its frequency is very high. for example , mega HZ, voltage is 6V,10V
5. In this device there is no connection of battery, as like fan, oven, are called electrical device. Are called electrical device.

Which device connect with battery as like, transistor, electronic capacitor ,diode etc.

6. The main difference between electrical and electronics is, in electrical we study current through conductor. Electronics we study current through semiconductors. And in electrical we study current through conductor


In electronic engineering we study about current through semiconductor. . Both are independent but highly related with each other. Becaz the aim of both branches is utilize current for useful purposes.

7. In this type device take the energy of electric current and transform it in simple ways into some other form of energy as like, light, heat, or different motion. As example The heating elements in a toaster turn electrical energy into heat so you can burn your toast.

Electronic devices are designed to manipulate the electrical current itself to coax it into doing interesting and useful things.

8. In electrical system large current required for operate of electrical circuit., as like heater, toaster etc.


In an electronic system small current required for operation of electronic circuit.

9. This is the field of Engineering that generally deals with the study and also application of electricity, electronics, and electromagnetism.

Electronic field is an Engineering discipline where non-linear and active  electronics and electrical components and also devices such as electron tubes, and semiconductor devices, especially diodes, transistor and also integrated circuits, etc. electronic circuits,

10. In electrical system electrical component larger than electronic component , as like transformer, capacitor etc.

In electronic system electronics component smaller than electrical component, as like transformer. Capacitor its.

 Hence it is the main basic difference between electrical and electronics if you will find any incorrect above please comment below in comment box.

For knowing more about the difference between electrical and electronics . you must watch this video


Breaking of dc motor

In this article we will discuss about the breaking of dc motor. we will also learn that how to stop a dc motor

Breaking of D.C Motor

Breaking is used for stopping for a motor and its load. Mechanical braking and electric breaking are used. In case of mechanical breaking it is difficult to achieve a smooth stop because it depends on the condition of the breaking surface and on operator skills. The electric breaking may be done for various reasons such as.

Main reason of breaking of dc motor

1. To extend the brake power of the mechanical brakes.
2. Increase the life of mechanical breaks
3. To generate the electrical power and improve the energy efficiency.
4. in emergencies to stop the machine instantly.
5. in production process by reducing the stopping time.

Electric breaking is simple. The electric motor can be made to work as a generator by suitable terminal conditions and absorb mechanical energy. This converted mechanical power is dissipated / used for electrical network.

Breaking can be broadly classified into various

1. Dynamic breaking

2. Regenerative breaking

3. Reverse voltage breaking or plugging

1. Dynamic breaking

In dynamic breaking the motor is disconnected from the supply and connected to a dynamic breaking resistance. In figure. This is done by changing the switch from position one to  two . The supply  to the field should not be removed. Due to the rotation of the armature during motoring mode and due to the inertia, the armature continues to rotate. An Emf is induced due to the presence of the field and the rotation.
This voltage drives a current through the breaking resistance. The direction of this current is opposite to the one which was flowing before change in the rotation.
This voltage drives a current through the braking resistance. The direction of this current is opposite to the one which was flowing before change in the connection.
Therefore, torque developed also gets reversed. The machine acts like a brake. The torque speed characteristics separate by excited shunt of the machine under dynamic breaking mode is as shown in figure. For a particular value. The positive torque corresponds to the motoring operation. Here the machine behaves as a self-excited generator. Below a certain speed the self-excitation collapses and the braking action becomes zero.

2.Regenerative breaking

breaking  of dc motor ,,  dc motor breakingThis braking is commonly used in electric trains. This braking is applied when the load on the motor has overhauling characteristics as in downgrade motion of an electric train. Regenerating occurs when back EMF> voltage. When the overhauling load acts as a prime mover and so drives the machine as a generator.  Hence, armature current changes, so armature torque is reversed and speed falls until Back EMF < voltage. During slowing down of the motor, power is returned to the line which may be used for supplying another train on an upgrade.

3. Reverse voltage breaking or plugging

In this method, connections to the armature terminals are reversed so that motor tends to run in the opposite direction as shown in figger.  Due to the reversal of armature connections. Applied voltage V and back EMF start acting in the same direction around the circuit. In order to limit the armature current to a reasonable value. It is necessary to insert a resistor in the circuit while reversing armature connections.
This breaking is commonly used in controlling elevators; rolling mills etc. here the connection to the armature terminals is reversed so that motor tends to run in the opposite direction. Because of this reversal, both applied voltage and back EMF start acting in the same direction.  A resister is inserted I the circuit to limit the armature current to exceed the limit.


single phase series motor

In this articale we will disscuss about the single phase series motor, we will disscuss in detail that what is single phase series motor.
single phase series motor and their working

Single phase series motor


When a dc drives motor equipped with a laminated field is connected  to ac single phase, the lagging reactance of the field coil will reduce the field current. While starting such a motors, armature windings connected to commutator segments shorted by the brushes look like shorted transformer turns to the filed. 



This leads to arcing and sparking at the brushes as the armature begins to turn. This problem is more when speed increases, which shares the arcing and sparking between commutator segments. The lagging reactance and arcing brushes are only tolerable in very small uncompensated series ac motors operated at high speed. Series ac motors smaller than hand drills and kitchen mixers may be UN compensated.




single phase series motor and their working


According to figger the circuit diagram for speed control of an ac series motor using triac. If the firing angle is increased, the voltage available across the motor will decrease, changing the speed of the motor.