How to make extension board?

Extension board as the name implies it is used for extending the circuit means providing the power supply at the desired place.
Extension boards are part of every house ,every commercial establishment and even every industrial establishment. Extension boards are readily available in the market and these can be designed as per requirements.
There is very simple circuit diagram of an extension board. You can design extension board from one switch socket to as many as you required. It is easy to design the extension board at home very easily and it is very cheap method of constructing the extension board instead of buying the same as it is very costly affair.


Extension board consists of following:-
1. Switches
2. Sockets
3. Extension cord
4. Box on which switch sockets mounted

Below is the method for making an extension board. Circuit diagram for the same is as shown below:-

Phase is circulated in sockets through switches and neutral and earth are connected at every socket directly.
You can install 5A or 15 A switch and sockets as per your load requirements.
If you are using 3 no.s 5A switch sockets then a 2.5 mmsq copper wire for phase, neutral and earth will be sufficient
If you are using 3 no.s ,15 A switch sockets then wire should be 4 mmsq copper.
As you keep on increasing no. of switch sockets you should have to increase the size of wire accordingly.
All connections should be tightly done and no loose wiring should be remain as otherwise it leads to short circuit and shocks. So double check should be done for checking tightness.

After doing the connections as stated above. Connect a plug top as per rating of switch and sockets and now you will ready to use your extension board.

Repairing Extension Board:-
You can also repair extension board very easily. If there is fault in any switch, Socket or wire then same can be replaced and repairing of extension board can be done.

One thing which must be kept in mind that if your are putting load on all sockets then connection for the same should be taken from socket or mcb of rating according to load connected to the extension board as otherwise it may leads to fault in socket or MCB from load is taken.

Cost of Making extension Board at Home:-
Cost of Making extension board is very low in comparison to extension board available in market .e.g.  an extension board consisting of anchor Make switch sockets will cost you around about 500-600 for 3 Switch/ sockets and if you made it at home you will save 50% cost i.e. cost of making extension board at home is 300-400/-
Also you will make good quality extension board at home.

Inverter Air conditioner Working principle; Saving with Inverter AC

We have seen and used Air conditioners which directly run on electricity and consume power according to capacity of air conditioner irrespective of temperature settings of Air conditioners. Inverter technology in air conditioners has changed whole scenario in world of air conditioners. 

There are following advantages of inverter air conditioners:-

(i)                  Quieter operation

(ii)                More economical operation and lower down electricity bill

In Inverter technology , inverter equipped in air conditioners has the ability to control the compressor’s speed and so as the temperature which leads to draw lower current when temperature is set higher and near auto stop, which ultimately leads to lower power consumption.

Inverter used in this technology is like inverter used in houses for emergency power supply but added to this is microcontroller which used to automatically adjust the temperature and current of compressor.

Since it provides smooth operation as compressor start and stop are smooth as current is controlled to compressor through Voltage/ Frequency control method so jerk operations of compressors are avoided. Since there are no jerk operations so operation of these air conditioners is smooth and quieter. Smooth operation will leads to sharp fluctuations in load which extends life of both equipment and power source supply. This will leads to lower breakdowns.

Difference between Fixed Speed Compressors and Variable Speed Compressors:-

Fixed Speed compressors start and stop automatically at a particular set temperature but in Variable speed compressors inverter regulates the desired temperature by regulating the capacity of compressor.  

Fixed Speed compressors always runs at 100% capacity but in Variable speed compressors compressor runs at partial loads as per requirements.

Also in our houses we can’t ascertain the exact size required for a room which leads to oversized/ undersized air conditioners. So by using inverter AC’s oversize factor can be reduced. If we install higher capacity AC in our room then there will be higher power consumption  irrespective of working hours of air conditioner. But in inverter AC’s Power consumption will get controlled.

There are following advantages and disadvantages of using inverter Air conditioners:-

Advantages of Inverter Air conditioners:-

(i)                 Higher efficiency of air conditioners as no. of start and Stop cycles get eliminated

(ii)               Effective temperature control can be achieved

(iii)                Higher equipment life as these have smoother operation

(iv)                Lower breakdowns

(v)                 Quieter operation

Disadvantages of Inverter Air conditioners:-

There are following disadvantages of Inverter Air conditioners:-

(i)                   Energy loss during power conversion to DC and AC again leads to losses of 4-6 %

(ii)                 Higher initial cost as inverter leads to added cost

(iii)                Complexity of circuit made difficult to repair

Price and Payback period:-

A 1.5 Ton Air conditioner consumes 1.5 KWH as it is assumed that 1TR consumes 1KW etc
Calculation for 8hrs/ day

Operation of Fixed speed Air conditioners
For 8 hrs of operation power consumption will be = 1.5 X 8 = 12 units

For a Inverter AC
An Inverter AC will operate for 30 minutes and for rest 30 minutes it will maintain the temperature.  During maintaining the temperature for rest 30 minutes power consumption will be 300 W/Hr.

So power consumption /Hr= 0.750+0.300= 1.05 KWH

For 8 Hrs operation power consumption  will be= 1.05 X 8= 8.4 Units

So Power saving will be = 12- 8.4 = 3.6 KW/ 8 Hrs

So do your calculations before buying any Air conditioner.

There will be price difference of 10,000-15,000 between inverter Air conditioner and split Air conditioners.

So if we consider 12 Hrs operation for 180 days power saving with Inverter AC will be= 12.6 X 180 = 2268 Units/annually

Rate per unit = 8 Rs

So Annual Savings will be= 18144/-

So payback for inverter AC’s is 3 months so do consider these before buying the Air conditioners. 

To know about new technology in Air conditioners visit:-
http://electrialstandards.blogspot.in/2017/04/hybrid-conditioners-unknown-facts.html

Hybrid Conditioners Unknown facts

In this world technology is keeps on changing so as the people. As people keeps on looking for new technology. Now you have seen that in air conditioners alone there are so many technology changes taking place. In past inverter Air conditioners were launched which consumes very low power. Now Hybrid Air conditioners are launched.

Now 1^st under understand what is hybrid means???

Hybrid Air conditioner means which can run two power sources/fuel for running an air conditioner. In hybrid 1^st source is electricity and another is by using solar energy.

These Air conditioners made to run on Solar power. These Air conditioners can run 100% on solar power. Another power source is taken as optional as in some cases when solar power is not available then that source can be used.

As these Air conditioners can run 100% on solar power these AC’s are equipped with inverter and battery system so that these air conditioners can run in night hours also. During day time these batteries get charged and will provide power through inverter in night hours. In Day time AC’s can run directly from solar power through inverter.

Companies which are making these AC’s are giving 25 years warranty on power generation capability of solar panels and 10 years warranty on solar panels. So this means that there isn’t any cost involve on solar panels replacement for life time, but following points must be taken care before buying these AC’s:-

1.       Space required for AC’s :- Since these AC’s are equipped with Inverter and batteries so Larger space will be required for accommodating the same.

2.       Life of Batteries and Inverter:- Since Manufacturers are giving warranty on solar panel for 10 years but warranty for inverter and battery will be maximum 2 years so do consider the cost of replacement of batteries and inverter while calculating maintenance cost.

3.       Sun facing House:- Do some technical before installation as if your house isn’t sun facing then your purpose of installation of these AC’s get defeated.  

4.       High Initial cost:- These AC’s will have very high initial cost almost double of other AC’s, as there is added cost of inverter, batteries, Solar panels.

Although these AC’s will reduce burden on your electricity by huge amount but above parameters must be taken care before doing comparison between AC’s.

These AC’s are very efficient and having copper condenser which required lower power.

Let’s check Viability of installation of these Air conditioners:-

Let’s take 1.5 ton 5 start AC having power consumption of 1200 Watt/Hr which will run for 12 hours whole year. Now let’s take a Hybrid AC. Now let’s compare them:-

Initial cost of 1.5 ton 5 star AC = 55000/-

Initial cost of 1.5 ton Hybrid AC= 130000  /-

Electricity consumption per day= 12 X 1200= 14.4 KW/Hour

Electricity consumption for whole year= 14.4 X 365 = 5256 units

Electricity Bill for whole year= 5256 X 8 = 42048 Rs

Now considering Maintenance cost for both AC’s as same then :-

Total Cost of 1.5 ton 5 Star AC = 55000 +42048 = 97048/-

Which means 2 years required for recovery of cost of Hybrid AC’s in case of whole year usage.

Now after 2 years you have to bear cost of replacement of Batteries which is approx.= 20000/-

So that cost will leads to 2.5 years of recovery.

In places where usage is only for 6 months then Rate of recovery will be 5 years . So do consider these factors while installation of these AC’s 

Unknown facts about cylindrical capacitors

Cylindrical capacitors:-

Unlike plate capacitors where 2 plates are used to form a capacitor, cylindrical capacitors are made by using two concentric cylindrical shells or wires and these two cylinders and wires are separated by using a dielectric medium.

Only difference between plate capacitor and cylindrical capacitor is its shape.

Electrical cable is best example for cylindrical capacitors.

How to calculate capacitance of a Cylindrical capacitor:-

For Calculating capacitance of a cylindrical capacitor let’s take radius of inner cylinder as r1 and outer cylinder as r2. Now let’s take permittivity of dielectric material used to form capacitor as  εa.

As in case of plate capacitor where one plate is acts cathode and other acts as an anode now in similar case let’s take inner cylinder charge per meter length on outer surface of inner cylinder as +q and similarly on inner surface of outer cylinder as –q coulombs.

In practical +q charge is considered to be on axis and outer circle is earthed so that person touching the capacitor doesn’t get the shock.

Now for calculating capacitance of capacitor:-

Surface area of the coaxial cylinder = 2

x= Radius of cylinder a meter and

Length =1 meter

Now electrical field intensity at “x” meter away from center of inner cylinder is as below:-

Ex =     Q                   Volt/Meter

        2πεoεax       

Where εo= Permittivity of vacuum or permittivity of free space, its value is 8.84 x 10^-12 Farad/meter

Potential difference between two plates or two cylinders is as below:-

So more will be the length of capacitor more will be the capacitance.

Capacitor is also known as condenser.

Dark lamp method of Synchronization of machines

Synchronization of Machines using dark lamp method:-

If phase sequence of running machine is RYB and incoming machine who is to be synchronized with the system is abc, than synchronization switch would be put across contacts a-R, b-Y, c-B respectively. Simultaneous closure of these switches causes synchronization of incoming machine with the running machine.

In dark lamp method of synchronization , There identical lamp’s L1, L2, L3 are contacted across a-R, b-Y, c-B respectively.  Voltage rating of these lamps should be twice the rated line to neutral voltage of the machine. Correct phase sequence can be verified if all the three lamps become dark together and bright together with same intensity of brightness. If same doesn’t happens than by changing any 2 terminals of incoming machine correct  phase sequence can be achieved.

Image below shows how to Synchronize machines using dark lamp method:-

If lamps never attain a dark phase but intensity of brightness of lamps changes with time then this indicates that there is high voltage difference. The excitation of incoming machine must be varied so that dark phase of all lamps is obtained.

Image above shows how various configurations during that method

For maximum brightness case rating of lamp selected should be 2 times the neutral voltage

If the lamps are dark or glow with the same intensity at all time than it means that frequency of incoming machine has become exactly equal to the frequency of running machine. In that case frequency of incoming machine should be adjusted in such a manner that interval between successive dark phases is maximized. That will ensure that frequency difference has become very low. Under these conditions, direction of dark period would become long enough to correctly anticipate the middle of dark period at which the synchronization switch should be closed to ensure proper synchronization of incoming machine with running machine.

 If Magnitude difference between 2 phases is very high than lamp will not be dark

At minimum 30% of rated voltage , we can just see the brightness of lamp.

When frequency of phase difference between phases is same then we can see constant brightness of lamp.

For incoming machine Interval between successive darks must be maximum.

Regenerative,Dynamic and Plugging braking

Brake obviously used to reduce the speed of any moving, rotating equipment’s. In day to day activity we use brakes in vehicles to stop them or reduce the speed of the same.

We come through braking of 2 types:-

(i)                  Electrical Braking

(ii)                 Mechanical braking

In mechanical braking speed is reduced by using mechanical process. But in electrical braking both electrical and mechanical systems are used for braking.

Electrical braking system works on the principle of reversing the direction of flux.

In most of systems motor is allowed to slow down and eventually stops after switching off the power supply of the motors. But for certain systems braking are needed to be provided. There are various types of motors such as Induction motors, DC motors, Single phase motors, And Synchronous motors etc. As these all types of motors are different from each other so type of braking method will also differ from each other.

There are following type of electrical braking systems:-

1.                   Regenerative braking

2.                   Dynamic braking

3.                   Plugging

Above stated types will be used for all types of motors, Now let’s discuss about them briefly in this article:-