What is Electrical Power?
In electrical circuit, electrical power depicts the amount of energy transferred per unit time through the circuit. Measures electrical power in watts (W) where the letter P is generally used to denote this quantity power at a particular time is the product of current and voltage in the circuit.
What is Power Factor?
In AC currents, both the current and voltage are periodic functions of the time. The values V (or) I correspond to the Root Mean Square (RMS).
RMS is the logical square root of the arithmetic mean of the square of numbers check the root mean square calculator for more information. Known voltage of electrical outlets
- 230V in EU and Australia,
- 110V in America and Canada,
- 100V in Japan
is RMS voltage.
In AC circuits it is quite possible that the current and voltage might not be in phase with each other.
There are the maximum value of the current and the maximum value of the voltage. It is quite possible to have the maximum current before or behind the maximum voltage.
This results in the transfer of power as being less efficient. The condition occurs when the current and voltage are in-quadrature that is leading by 90 degrees, and therefore, the transmitted power is zero.
The power factor simply depicts the level of phase shift between the current and the voltage.
Here, it is that if both the voltage and current are in phase, the power factor is 1.
It is less than one and is equal to zero in the completely out of phase case that is 180 degrees.
In relation to power factor all the devices shall be as follows:
- If the load is strictly resistive kind, as in the case of an electric kettle or an electric heater, then power factor is 1.
- An arrangement with inductive or capacitive components displaces the current and the voltage by phase.
- This makes its power factor to be less than 1.
The power factor is more difficult to determine if you possess a power quality analyzer on hand.
Check this list for the power factors of a few common household devices:
| Household Devices | Power Factor (pf) |
|---|---|
| Lamps Using a Standard Bulb | 1 |
| Fluorescent Lamps | 0.93 |
| Typical Induction Motor | At half load = 0.73; At full load = 0.85 |
| Electric Oven (Resistive Heating Element) | 1 |
| Inductive Ovens | 0.85 |
Electrical Power Calculator
When computing the electrical power, it is obligatory to determine the current, voltage and power factor of the item in question. On devices connected to electrical outlet the voltage is only that of the domestic power. Most of the current drawn by the device is standard and it can be found either marked on the plug or on the device.
The following formula is used to describe the electrical power of the system in terms of the current (I) & voltage (V) of the system:
In alternating current (AC) circuits, the formula for calculating electrical power is as follows:
P= V × I × pf
In direct current (DC) circuits, the formula for calculating electrical power is as follows:
P= V × I
Where
I – Current (A)
V – Voltage (V)
P – Power (W).
pf – Power Factor
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