Electrical Resistance Formulas
| Quantity | DC | Single Phase AC | Three Phase AC |
| Current (I) | I = V/R I = P/V I = √P/R | I = P / (V x Cosθ) I = (V/Z) | I = P / √3 x V x Cosθ |
| Voltage (V) | V = I x R V = P / I V = √ (P x R) | V = P/ (I x Cosθ) V = I / Z | VL = √3 VPH or VL = √3 EPH VL = VPH |
| Power (P) | P = IV P = I2R P = V2/R | P = V x I x Cosθ P = I2 x R x Cosθ P = ( ... | P = √3 VL IL CosФ P = 3 VPh IPh CosФ |
| Resistance (R) | R = V/I R = P/I2 R = V2/P | Z = √ (R2 + XL2) Z = √ (R2 + XC2) Z = √ ... | Z = √ (R2 + XL2) Z = √ (R2 + XC2) Z = √ ... |
| Quantity | DC | AC (3-Phase) |
|---|---|---|
| Power (W) | P = V x I P = I2 x R P = V2 / R | P = √3 x VL x IL x Cos Ф P = 3 x VPh x IPh x Cos Ф P = 3 x I2 x R x Cos Ф P = 3 (V2 / R) x Cos Ф |
How do you calculate three phase?
To convert vehicle speed to wheel’s RPM:
- Multiply wheel’s RPM with the tire diameter.
- Multiply the product with 60 and π.
- Divide the resultant by 63360.
How do you calculate 3 phase power factor?
Three Phase Power and Current
- Single phase system. Given the kW and power factor, the kVA can be easily worked out. ...
- Three phase system. The main difference between a three-phase system and a single-phase system is the voltage. ...
- Unbalanced Three Phase Systems. The above deals with balanced three-phase systems. ...
- Balanced Voltages. ...
- Unbalanced Voltages. ...
- Conclusion:
How do you measure 3 phase voltage?
- Single-Phase wattmeter Connection
- Single-Phase Three-Wire Connection
- Three Phase Three-Wire Connection (Two Wattmeter Method)
- Three Phase Three-Wire Connection (Three Wattmeter Method)
- Blondel’s Theorem: Number of Wattmeters Required
- Three-Phase, Four-Wire Connection
- Configuring Measurement Equipment
What is the formula for calculate 3 phase power MVAR?
- The 10 MVAR capacitor bank is showing 10.8 MVAR. ...
- The remaining transformers supply less MVARs due to the capacitor contribution.
- Due to transformer 3 being out of service, the remaining transformers will supply the entire station load. ...
- The phase angle difference between bus 5011 and bus 5010 has increased from 1.92 (3 circuits in parallel) to 2.87Ë.
What is the formula for calculating 3 phase power?
A = 1000 × kW / (3 × PF × V) For a 3-phase power supply calculation, you need to multiply 1000 by the power (kW), divided by three times the power factor times line-to-neutral RMS voltage (V).
How do you calculate phases in three-phase?
0:041:06Verifying Three Phase Voltage - A GalcoTV Tech Tip - YouTubeYouTubeStart of suggested clipEnd of suggested clipEach phase has to be checked. You can measure the first leg with the second one the first leg withMoreEach phase has to be checked. You can measure the first leg with the second one the first leg with the third one and then the second leg with the third one. Each reading should be the same if.
What are the three formulas for electrical?
P = ΔV2 / R We now have three equations for electrical power, with two derived from the first using the Ohm's law equation. These equations are often used in problems involving the computation of power from known values of electric potential difference (ΔV), current (I), and resistance (R).
How do you get 415V from 3-phase?
The three phase lines and the neutral together give a 3-phase 4-wire supply with a RMS voltage of 240√3 = 415V.
What voltage is one leg of 480?
The voltage between any one leg and ground will be 277 volts, and between any 2 hot wires will be 480 volts.
What is electricity formula?
W = Q × V = Q ( V2 − V1) Joule. Electric Current = Charge / Time. Electric Current = charge flowing through any conductor per unit time.
What are the 3 formulas in Ohm's law?
3-4: A circle diagram to help in memorizing the Ohm's Law formulas V = IR, I = V/R, and R= V/I.
How do I calculate kWh?
kWh Explained To calculate the kWh for a specific appliance, multiply the power rating (watts) of the appliance by the amount of time (hrs) you use the appliance and divide by 1000.
3-Phase Power Calculator: Amps To kW (1st Calculator)
You can freely use this calculator to convert amps to kW in a 3-phase circuit. You need to input the amps, voltage, and the power factor (it’s between 0 and 1, specific for each circuit):
3-Phase Motor Amps Calculation: kW To Amps (2nd Calculator)
To calculate the amps from kW, you need to input the kW, voltage, and power factor of a 3-phase motor. The calculator will dynamically calculate the current (amps) based on your inputs:
What is the purpose of a 3 phase power system?
In an electrical system, the phase system is used for the distribution of load. There are three different types of phase systems in use. The first one is a single phase, two phases, and the other three phase system. Single phase system contains two wires.
How many wires are in a single phase system?
Single phase system contains two wires. One is neutral and the other is phase wire. In two phase system, we divide the system into two parts. Each section of the alternating current is out of phase by half cycle. However, this two phase system is not much common. While in the three phases there are three wires.
What is power factor?
The power factor is the ratio of real power to apparent power. Most of the electrical engineering students do not distinguish between real power and apparent power. Real power is the amount of power that performs useful work. While Apparent power is the power supplied to the circuit. So the 3 phase formula is given below.
Power Factor
For pure resistive load and power factor = 1 the real power in a 400/230 voltage (line to line / line to neutral) 20 amps circuit can be calculated as
Brake Horsepower
Electrical - Electrical units, amps and electrical wiring, wire gauge and AWG, electrical formulas and motors.
What is balanced three phase system?
The above deals with balanced three phase systems. That is the current in each phase is the same and each phase delivers or consumes the same amount of power. This is typical of power transmission systems, electrical motors and similar types of equipment.
What is the relationship between kVA and kW?
The relationship between kVA and kW is the power factor (pf): which can also be expressed as: Single phase system - this is the easiest to deal with. Given the kW and power factor the kVA can be easily worked out. The current is simply the kVA divided by the voltage.
What is the impedance of an AC circuit?
Impedance is the resistance of AC circuits i.e. resistive, captative and inductive circuit (already mentioned above). Where “Z” is the impedance in ohms, “R” is resistance in Ohms and “X” is the reactances in Ohms.
What is the unit of inductance L?
The unit of Inductance “L” is Henrys “H”. It is also known as Ohm’s law for inductance.
What is three phase power?
Three-phase electric power is a common method of alternating current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by electrical grids worldwide to transfer power.
How much power can a three phase AC supply transmit?
As compared to a single-phase AC power supply that uses two conductors (phase and neutral ), a three-phase supply with no neutral and the same phase-to-ground voltage and current capacity per phase can transmit three times as much power using just 1.5 times as many wires (i.e., three instead of two). Thus, the ratio of capacity to conductor material is doubled. The ratio of capacity to conductor material increases to 3:1 with an ungrounded three-phase and center-grounded single-phase system (or 2.25:1 if both employ grounds of the same gauge as the conductors).
What is the voltage between a line and a load called?
The conductors between a voltage source and a load are called lines, and the voltage between any two lines is called line voltage. The voltage measured between any line and neutral is called phase voltage. For example, for a 208/120 volt service, the line voltage is 208 Volts, and the phase voltage is 120 Volts.
Why is a three phase circuit more economical than a two phase circuit?
A three-wire three-phase circuit is usually more economical than an equivalent two-wire single-phase circuit at the same line to ground voltage because it uses less conductor material to transmit a given amount of electrical power.
How many wires are needed for a wye?
There are two basic three-phase configurations: wye (Y) and delta (Δ). As shown in the diagram, a delta configuration requires only three wires for transmission but a wye (star) configuration may have a fourth wire.
When to use a four wire wye system?
Other non-symmetrical systems have been used. The four-wire wye system is used when a mixture of single-phase and three-phase loads are to be served, such as mixed lighting and motor loads.
How many wires are needed for a two phase circuit?
Two-phase circuits may be wired with two pairs of conductors, or two wires may be combined, requiring only three wires for the circuit. Currents in the common conductor add to 1.4 times the current in the individual phases, so the common conductor must be larger. Two-phase and three-phase systems can be interconnected by a Scott-T transformer, invented by Charles F. Scott. Very early AC machines, notably the first generators at Niagara Falls, used a two-phase system, and some remnant two-phase distribution systems still exist, but three-phase systems have displaced the two-phase system for modern installations.
Electrical Technology
All about Electrical & Electronics Engineering & Technology. Follow Electrical Technology on Facebook, Twitter , Instagram, Pinterest, YouTube, & Linkedin to get the latest updates or subscribe Here to get latest Engineering Articles in your mailbox.
Basic Electrical Formulas
Your email address will not be published. Required fields are marked *