ELECTRIC CURRENT

Electric current is the large number of electrical charge resulting from the movement of the electrons are negatively charged, flowing through a point in an electric circuit per unit time. An electric current can be measured in units of Coulomb / second or amperes. electrical current can be clasified to a direct electric current and alternating electric current.

direct electric current is the amount of electric current The set voltage in a fixed or unchanging. This means that the direction of the electric current has a frequency 0. direct electric current frequently encountered in electronic circuits such as mobile phones, dvd player, or other electronic circuits.
while the direct current electrical energy from the accumulator, batteries, etc..

alternating electric current is an electrical current where the magnitude of the voltage in a circuit constant amount per unit time in a circuit., and alternating electric currents having frequency values​​.
alternating electric currents encountered in many household appliances such as fans, water pumps, lighting, etc.. source of alternating current electric power from the power plant. (generator).

direction of the electric current is a positive charge to the negative charge this is different from the actual fact that the move is a negative charge (electrons).
electric current flows in a closed circuit, but can also occur leap into the air when the voltage is too high. (This case happens to thunder and spark plugs). 

as an illustration assuming current electricity were we lay like a stream of water.
amount of water flow per unit time as the number of electric current in a unit time in the electrical circuit. this resulted conductor used depend on the amount of electrical current. the greater the electrical current the more knowledgeable a penghantar.karena cross sectional area of ​​the cable when not able menhantarkan magnitude of the electrical current will result in the burning of a conductor, therefore the correct calculations necessary to determine a conductor in an electrical circuit. and it takes an act of protection against the dangers of overcurrent circuit in the conductor. security that can be used include fuses, MCB, NFB, etc.. 

electric current formula:Electric Current1. Current on Real Power (P)Line to neutral / 1 phaseI = P / (V x Cos Ø)Line to line / 3 phaseI = p / (√ 3 x V x Cos Ø)
2. Flow on Power Moot (S)Line to neutral / 1 phaseI = S / VLine to line / 3 phaseI = S / (√ 3 x V)

3. Flow on Reactive Power (Q)Line to Neutral / 1 phaseI = Q / (V x Sin Ø)Line to line / 3 phaseI = Q / (√ 3 x V x Sin Ø)Note:I = Current (Amperes)P = Real Power (Watts)S = The Moot (VA)Q = Reactive Power (VAR)V = Voltage (Volts)Power factor cos φ =Sin φ = power factor

Nominal FlowTo determine the current carrying capability of a conductor that supplies electrical equipment, must first know the amount of the nominal current of the equipment, which is usually the nominal flow is marked on the equipment nameplate. If it is not listed on the name plate of his then current carrying capability of a conductor can be searched using the following formula, the formula is used to determine the nominal current of the equipment used three-phase system:I = P / (√ 3 x V x Cos Ø)Note:I = current equipment (Ampere)P = Power input devices (Watt)V = Voltage (Volts)Power factor cos φ =

The relationship Flow Shock briefThe relationship Flow short can damage the plant because:

    Thermic Effect, If the short-circuit current lasts too long, the wires will be too hot, so the insulation is damaged.
    Effect of Dynamic, short-circuit current shock can damage the installation because the forces generated electro-dynamic. Short-circuit current shock is short-lived once.The relationship Flows In brief shock load L-LLs - b = k x (100 / Ub) x ln x √ 2The relationship Flows In brief shock Network L-LLs - j = k x (100 / (Ub + Uj)) x ln x √ 2Note:Is-b = short-circuit current at the load (Amperes)Is-j = short-circuit current on the network (Ampere)In = effective value nominal load current (Ampere)k = factor shock: for the installation of these factors can be determined experimentally.Ub = voltage loss in the generator or transformer (expense) on the nominal load current is expressed as a percentage of the nominal open terminal voltage (%).Uj = Loss voltage at nominal load current on the network which is connected briefly, expressed as a percentage of the nominal open terminal voltage of the generator or transformer (%).