The primary current is equal to the product of the secondary voltage and secondary current divided by primary current. The secondary current is equal to the product of the primary voltage and primary current divided by secondary voltage.
Besides, How is CT primary current calculated?
Calculate the CT ratio. The CT ratio is the inverse of the voltage ratio. In this example, the voltage ratio is 1:5, so the CT ratio is 5:1. This means the current level is stepped down 5 times where, if the primary current is 200 amps, the CT output is 40 amps.
Keeping this in mind, How do I calculate current? The current is the ratio of the potential difference and the resistance. It is represented as (I). The current formula is given as I = V/R. The SI unit of current is Ampere (Amp).
How do you calculate primary and secondary voltage?
Solve the equation Vs/Vp = Ns/Np where Vs is the secondary voltage, Vp is the primary voltage, Ns is the number of secondary windings and Np is the number of primary windings. Divide the number of secondary windings by the number of primary windings, and multiply the source voltage by this ratio.
How do you calculate secondary full load current?
Transformer
- Transformer full load current = kVA / (1.732 x Volt)
- Transformer full load current = 1000 / (1.73 2× 480) = 1203 Amp.
- Short circuit current at TC secondary (Isc) = Transformer full load current / Impedance.
- Short circuit current at TC secondary = 1203 / 5.75 = 20919 Amp.
How is CT calculated?
To calculate CT, multiply the free chlorine residual concentration (C) measured at the end of the contact time by the time (T) the water is in contact with free chlorine. To get the required CT value of 6, adjust the free chlorine residual concentration or the contact time.
How is CT rating calculated?
When analog ammeters are installed, we can easily determine the CT ratio by observing the meter full scale value and then divide that value by 5. Figure 3. Ammeter with a full scale of 150 amps. The meter in Figure 3 has a full scale of 150 amps.
How is CT meter reading calculated?
The multiplier is the CT ratio times the PT ratio. If you are not using PTs the multiplier is the CT ratio. For 200:5 CTs your ratio and your multiplier will be 200/5=40 Change the meter to read 200:5 if possible.
How do you calculate current from resistance and power?
You can see from the equation P = I² × R that for a given resistance the power depends on the current squared, so doubling the current will give 4 times the power.
How do you find current with resistance and power?
Ohms Law is used extensively in electronics formulas and calculations so it is “very important to understand and accurately remember these formulas”.
- To find the Voltage, ( V ) [ V = I x R ] V (volts) = I (amps) x R (Ω)
- To find the Current, ( I ) …
- To find the Resistance, ( R ) …
- To find the Power (P)
How do you calculate voltage and current?
The explanations here are that; Current equals Power divided by Voltage (I=P/V), Power equals Current times Voltage (P=VxI), and Voltage equals Power divided by Current (V=P/I).
How do you find secondary voltage?
The secondary voltage was measured through a Tektronix P6015 high-voltage probe with 1000:1 attenuation attached to a socket that is plugged to the end of the plasma antenna. The secondary current is measured by a Pearson 411 current transformer on the wire between the secondary coil and the plasma antenna.
How do you calculate secondary line voltage?
Primary line voltage = 2,400 V. Primary phase voltage = 2,400 V. Secondary line voltage = 2,400 divided by 10 = 240 V.
What is primary and secondary voltage?
For this tutorial we will define the “primary” side of the transformer as the side that usually takes power, and the “secondary” as the side that usually delivers power. In a single-phase voltage transformer the primary is usually the side with the higher voltage.
How do you calculate full load current?
Full load current I, I =P. / 1.732 * V Amps.
How do you calculate the secondary amps on a transformer?
Power rating in KVA (Kilo Volt Amperes), Primary voltage, Secondary voltage, Tap arrangement.
…
- Secondary voltages or Low Voltages (L.V) is 415 volts.
- Secondary Current (Current on Low voltages side) is 139.1 amps.
- KVA = (√3. V x I) /1000= (1.732 × 415 × 139.1)/1000=100 KVA.
What is full load primary and secondary current?
By full load is meant the load (obviously, on secondary) which would make transformer transfer it’s rated power from primary to secondary. For example when 50 kVA is on full load, it would be transferring 50 kVA from primary to secondary.
How do you calculate contact time disinfectant?
Step 1: Time is equal to 5,000 gallons x 0.3 (baffling factor) to get a working contact volume of 1500 gallons (assuming the tank is full to capacity). Divide 1,500 gallons by the peak hourly flow of 15 gallons per minute to get 100 minutes of time available. Step 2: Your contact time is 100 minutes x 1.5 mg/l.
How do you calculate CT burden resistor?
The following calculator can be used to determine a suitable burden resistor for use with the Z3 NetMeter:
- Burden Resistor Calculator. Ip = Rated Current.
- (Amps RMS) Vct = Rated Voltage.
- (Volts RMS) N = Turns Ratio.
- (Number of turns of the secondary winding) R = Burden Resistor.
- (Ohms) Burden Resistor Power.
How do you calculate current transformer ratio?
Recommended is a ratio slightly beyond the measured / defined maximum load current (In). Example: In = 1,154 A; selected transformer ratio = 1,250/5.
How is current transformer rating determined?
The rated power of the current transformer is the product of the rated load and the square of the secondary rated current and is quoted in VA. Standardised values are 2.5 – 5 – 10 – 15 – 30 VA. It is also permissible to select values over 30 VA according to the application case.
What is CT rating factor?
The basic formula for a 55°C rise CT is: Rating factor (RF) is a term, which applies to a current transformer. … Typical rating factors of CT’s are 1.0, 1.25, 1.33, 1.5, 2.0, 3.0, and 4.0. Many times the manufacturer will only list the CT rating factor at 30°C ambient (room temperature).
How do you choose CT ratio for protection?
For a metering CT, choose a burden VA equal to, or greater than, 125 % of the total combined VA of instruments connected to the secondary side. For a protective CT, please contact the manufacturer for assistance. Accuracy • For a revenue CT, the accuracy should be at least IEC 0.2 or 0.5 CL or IEEE 0.3 or 0.6 CL.