If it's a step up or step down transformer and you know the secondary side current, multiply the secondary current by the turns ratio. If you know the power in the secondary winding but not the current, divide the secondary power by the secondary voltage to get the secondary current and then multiply the secondary current by the turns ratio to get the primary current. The turns ratio is the number of turns on the secondary winding divided by the number of turns on the primary winding. For a step up transformer, the turns ratio will be greater then one. If it's a step down transformer, then the turns ratio will be less than one. If you don't know the turns ratio, divide the secondary voltage by the primary voltage to get the turns ratio.
The primary current is calculated as the secondary current divided by the voltage ratio. So if the voltage ratio is 2:1, the current ratio is 1:2.
The primary current is determined by the secondary current. So, if you don't know the secondary current, you cannot work out the primary current.If the secondary isn't connected to the load, then the primary current is simply the primary voltage divided by the impedance of the primary winding.You can, though, work out the 'rated' primary current (i.e. the value of current the primary can carry, continuously). For a single-phase transformer, this will be its rated apparent power (in volt amperes) divided by its rated primary voltage. So, in this particular case, we are looking at:rated primary current = (50 x 103) / (11 x 103) = 4.55 A
The turns ratio is the number of primary turns divided by the number of secondary turns. This is the same ratio as input current to output current. ie the turns ratio N = I1/I2
This is the current flowing in the primary circuit when full-load current flows in the secondary circuit.
Primary current is a flow to be measured that cannot be safely passed through the measuring device. A current transformer is used to provide a lower level, secondary current that can be passed safely through the measuring device. Primary current is measured as a secondary current, multiplied by the turns ratio in the current transformer.
Tis question is incompleet.1000 va =1 kva.This is the power capacity of transformer. A transformer having 2 currents Primary current and secondary current . for that we required both voltage. Simply we can calculate by a formula Voltage x Current x 0.8(power factor)=1000.
The primary current on a loaded transformer depends on the secondary current, which is determined by the load. So, if you know the secondary load current, then you can use the turns ratio of the transformer to determine the primary current:Ip/Is = Ns/Np
First find the ratio of the transformer. 6600/220 volts. Second find the secondary current, I = W/E, 99000/220. Third divide the secondary current by the transformer ratio. The answer will be the primary current. To check your answer (W (or VA) = V x A) multiply the primary current times the primary voltage and the secondary current times the secondary voltage and they should both equal the transformer's kVA.
The primary current is determined by the secondary current. So, if you don't know the secondary current, you cannot work out the primary current.If the secondary isn't connected to the load, then the primary current is simply the primary voltage divided by the impedance of the primary winding.You can, though, work out the 'rated' primary current (i.e. the value of current the primary can carry, continuously). For a single-phase transformer, this will be its rated apparent power (in volt amperes) divided by its rated primary voltage. So, in this particular case, we are looking at:rated primary current = (50 x 103) / (11 x 103) = 4.55 A
DC Current divided by 1.225
Current is calculated on the load. If your question on transformer primary current, then use the formula N1I1=N2I2, where N1 and N2 are primary and secondary coil turns and I1 and I2 are current in respective coils. This is very basic simple formula. You have reframe your question more specifically.
Rated voltage is the voltage at primary side. Rated current can be found from the equation, Rated Current= Output KVA / Output rated voltage
It depends on the voltage on line side. KVA is simply thousand volt-amps, so you need to know voltage in order to calculate amperes.Another AnswerThe rated primary current is the rated apparent power of the transformer, divided by the rated primary current. However, the actual primary current is determined by the actualsecondary load current in proportion to the reciprocal of the turns ratio.
The current in the secondary when the voltage is twice the primary will be one half of the primary. The current in the primary when the voltage is twice the secondary will be twice the secondary.
The turns ratio is the number of primary turns divided by the number of secondary turns. This is the same ratio as input current to output current. ie the turns ratio N = I1/I2
The secondary current of a transformer is determined by the load and the secondary voltage applied to that load, and this, in turn, will determine the primary current by the inverse of the turns ratio. However, if you are asking about a transformer's rated secondary and primary currents, then you need to divide the transformer's apparent power rating (expressed in volt amperes) by the rated secondary and primary voltages respectively.
This is the current flowing in the primary circuit when full-load current flows in the secondary circuit.
I am assuming the question is about the power / distribution transformer and not the current transformer. The primary current is a function of load connected on secondary. With the open secondary, there is no load, no current, it is open circuit. Hence no primary current. However there is always some small amount of no load current in the primary winding.