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In this article you will learn about how to calculate the charging time and current of battery. So let's get started. Suppose you have a 120Ah  lead acid battery and you want to calculate the charging time, so have required this formula Charging time of battery = Battery Amp Hour / Charging Current ∴ T = Ah / A Now, let's find the charging current. The charging current should be 10% of the amp hour rating of battery. So,  Charging current of battery = Amp hour of battery * % of losses ∴120 * (10/100) = 12A This is in ideal case but you have to consider losses also , so considering losses you have to take more amp. It can be 12 to 12 A for charging purpose. Suppose that the charging amp is 13A. Charging time of battery = Battery Amp Hour / Charging Current  =120/13             =9.23 Hour       But this result is in ideal case, in real noted that 40% of losses in case of battery charging. By con...

[accordion] [item title="In this article"] 1-Why AC rated in Tons? 2-How many kW and HP are there in 1 Ton? 3-How many Ampere will a 2 Tons AC draw in Single Phase & Three Phase System? 4-How many 2 Ton A.C (Air conditioner) can I run on a 25 kVA Generator [/item] [/accordion] 1-Why AC rated in Tons? Air conditioners(AC) are rated in Tons instead of using the kW unit. Just because of Air conditioners are designed on the basis of the quantity of heat removal from any specific area(office, classroom, hall). Quantity of heat is termed in Tons unit. If an air conditioner is able to remove 2000 kilocalories of heat (8240 kilojoules or 24000 BTU )of heat in an hour that AC rated as 2 Ton of AC. Also, this is the same for the refrigeration system. Definition of Ton: A Ton of refrigeration (RT) is a unit of power used to describe the heat extraction capacity of an air conditioner or refrigeration equipment. It is defined as the heat of fusion absorbed b...

The difference between the electronic and ordinary regulator is that in electronic regulator power losses are less because as we decrease the speed the electronic regulator gives the power needed for that particular speed.  But in the case of ordinary rheostat type regulator, the power wastage is same for every speed and no power is saved.  In electronic regulator, TRIAC is employed for speed control. by varying the firing angle speed is controlled but in rheostat control resistance is decreased by steps to achieve speed control. Read Also: Why AC rated in Tons? A Guide about Airconditioner and Refrigeration What is the difference between MCB & MCCB, where it can be used? Why in a three pin plug the earth pin is thicker and longer than the other pins? 4 most important questions for every electrical maintenance engineer Why ELCB cannot work if Neutral input of ELCB does not connect to ground?

If 200w, 100 w and 60 w lamps connected in series with 230V AC , which lamp glow brighter? Each lamp voltage rating is 230V. Each bulb when independently working will have currents (W/V= I) For 200 Watt Bulb current (I200) =200/230=0.8696 A For 100 Watt Bulb current (I100) =100/230=0.4348 A For 60 Watt Bulb current (I60) =60/230=0.2609 A Resistance of each bulb filament is (V/I = R) For 200 Watt Bulb R200= 230/0.8696= 264.5 ohms For 100 Watt Bulb R100= 230/0.4348 = 528.98 ohms and For 60 Watt Bulb R60= 230/0.2609=881.6 ohms respectively Now, when in series, current flowing in all bulbs will be same. The energy released will be I2R . Thus, light output will be highest where resistance is highest. Thus, 60 watt bulb will be brightest. It has highest resistance & minimum current requirement. Highest voltage drop across it X I [which is common for all lamps] =s highest power. Note to remember: Lowest power-...

1.) If one lamp connects between two phases it will glow or not? If the voltage between the two phases is equal to the lamp voltage then the lamp will glow. When the voltage difference is big it will damage the lamp and when the difference is smaller the lamp will glow depending on the type of lamp. 2.) Two bulbs of 100w and 40w respectively connected in series across a 230v supply which bulb will glow bright and why? The two bulbs are connected in series they will get an equal amount of electrical current but as the supply voltage is constant across the Bulb (P=V^2/R).So the resistance of 40W bulb is greater and the voltage across 40W is more (V=IR) so 40W bulb will glow brighter. 3.)  What happens if we give 220 volts dc supply to bulb or tube light? Bulbs or any other devices or equipment which are designed to operate on AC supply, such that it offers a high impedance to AC supply. Normally they have low resistance. When DC supply is applied, due to low re...

It depends upon R=ρL/A where area (A) is inversely proportional to resistance (R), so if the area (A) increases, resistance decreases & if resistance is less the leakage current will take low resistance path so the earth pin should be thicker.  It is longer because the first to make the connection and last to disconnect should be earth Pin. That assures the safety of the person who uses the electrical instrument.  Why AC rated in Tons? A Guide about Airconditioner and Refrigeration Why ELCB cannot work if Neutral input of ELCB does not connect to ground? What is the difference between MCB & MCCB, where it can be used? 4 most important questions for every electrical maintenance engineer Difference between an Electronic regulator and ordinary rheostat regulator

Most people are confused about the differences between MCB and MCCB. Although both are circuit breakers, there key differences makes them specially made for specific jobs.  MCB is miniature circuit breaker which is thermal operated and uses for short circuit protection in small current rating circuit. Normally it is used where the normal current is less than 100A.  MCCB moulded case circuit breaker and is thermal operated for overload current and magnetic operation for an instant trip in short circuit condition. Under voltage and under frequency may be inbuilt. Normally it is used where normal current is more than 100A. The main difference between the both circuit breakers is their capacity. The MCB is mainly used for low-energy requirements like home wiring or small electronic circuits and the MCCB is more suited in providing energy for high-power equipment. Key Differences:  An MCB has less than 100 amps while an MCCB goes as high as 2,500 amps. The...

Earth leakage circuit breaker (ELCB) is used to detect the earth leakage faults. If phase and neutral both are connected in an ELCB, the current will flow through the phase and that same current will have to return to neutral, so the resultant current is zero.  If a ground fault occurs on the load side, current from phase will directly pass through earth and it will not return through the neutral connection. That means one side current is going and another side not returning and hence because of this difference in current ELCB will trip and it will safeguard the other circuits from faulty loads.  If the neutral point is not grounded then fault current will be very high and that full fault current will come back through ELCB, and there will be no difference in current.  Read Also: Why AC rated in Tons? A Guide about Airconditioner and Refrigeration What is the difference between MCB & MCCB, where it can be used? Why in a three pin plug the earth pi...