Table of Contents
- 1 What is an electrical load
- 2 What is inductive loads
- 3 What is resistive loads
- 4 What is capacitive loads
- 5 Different types of loads in a power system
Is ac an inductive load? Yes, air conditioners are inductive load. But, there is more about electrical loads that you need to know to understand more about inductive loads.
What is an electrical load
An electrical load is an electrical component or device that uses electrical energy and converts this into a different form of energy. Air conditioners, electric lamps, resistors, and motors are some of the best examples of an electrical load. These can be classified based on different factors.
Electrical loads are part of the electrical circuit where the current gets transformed into something useful. An electrical load will convert electricity into light, motion, or heat. Simply put, the specific part of the circuit connected to the well-defined output terminal is regarded as an electrical load.
Three basic types of loads can be found in circuits and these are inductive loads, resistive loads, and capacitive loads. These differ in terms of how they use up power in an alternating current setup. Resistive, inductive, and capacitive types of load loosely correspond to heating, mechanical, and lighting loads. There are some engineers and scholars who refer to nonlinear and linear although these terms are not used as much.
What is inductive loads
Inductive loads are loads that power electric motors. These can be found in different devices and household items with moving parts such as vacuum cleaners, fans, washing machines, dishwashers, and compressors in air conditioners and refrigerators.
Current in pure inductive load follows a sinusoidal pattern peaking once the voltage sine wave has peaked for the zero, maximum, and minimum points to be out of phase.
Examples of inductive load
The most common examples of inductive load include:
- Electric motor
- Washing machine or anything with motor inside it
- Reactors used in the power systems
Inductive load properties
The following are the most notable properties of an inductive load:
- The current waveform and voltage of inductive loads are out of phase with one another by 90 degrees.
- Inductive loads have a lagging power factor.
- Power is flowing from the source to the load and vice versa.
- Inductive loads consume reactive power only.
This specific type of load is not an easy load and it can create lots of problems within the system. Switching the load is a bit difficult since the current is lagging behind the voltage by 90 degrees in this type of load. As you might already know, a circuit breaker is opening at a current zero condition. When you look at the voltage and current waveforms of this load, you will find that once the current is zero, the voltage is already maximum.
Once the circuit breaker has opened at current zero, there is the maximum voltage across breaker contact. This is why it is crucial to switch inductive load. This type of load can also heavily affect the system’s power factor, increasing the electricity bill. Please read our previous guide if you want to learn how to reduce electricity consumption of air conditioner.
What is resistive loads
The loads made up of heating elements are categorized as resistive loads. It is a type of load drawing current in sinusoidal waxing and waning pattern in connection with sinusoidal voltage variation. The zero, maximum, and minimum points of voltage and current values line up over time. This is purely resistive with no other elements included.
Examples of resistive load
The best examples of resistive loads include:
- Incandescent lights
- Coffee makers
- Space heaters
- Other loads made up exclusively of heating elements
Resistive load properties
Here are the common properties of resistive loads:
- Resistive load consumes active power alone.
- Current waveform and voltage of resistive loads are in perfect phase with one another.
- Power flows from the source to the load all the time.
- Power factor of resistive load is unity.
What is capacitive loads
In capacitive loads, voltage and current are out of phase similar to inductive loads. The main difference here is that with capacitive loads, the current reaches maximum value way before the voltage does. The current waveform will lead the voltage waveform unlike in inductive load where the current waveform is lagging it.
Capacitive loads in engineering don’t exist in standalone format. No device can be classified as capacitive in the same way that air conditioners are considered inductive load and light bulbs are categorized as resistive loads.
However, capacitors in large circuits come in handy in controlling the use of power. These are usually included at the electrical substations for improving the system’s overall power factor. Inductive loads tend to increase the cost of a certain power system and lower the amount of power that gets converted to another energy form. The installation of capacitors is meant to offset that drain.
Capacitive load misconception
Capacitive load doesn’t exist in standalone format. The capacitor banks are being installed for improving a system or load’s power factor. Their role is to supply the reactive power. This means that capacitor banks cannot be referred to as capacitive load since the load is something that absorbs the power.
Different types of loads in a power system
There are other types of loads that you can find in power systems.
This is made up of electrical loads meant for commercial use such as in malls, shops, and restaurants. It is a type of load that occurs for several hours throughout the day.
This is composed of load demand by different industries. This includes all the electrical loads that are used in the industries together with employed machinery. These can be connected the entire day.
Pumps and motors used in the irrigation systems for supplying the water for farming belong to this category. Irrigation loads in general are supplied during the night or off-peak hours.
It is a type of load composed of the drainage system, water supply, street lighting, and others.
Residential or domestic load
Domestic load is made up of fans, lights, electric appliances, and others.
Traction loads include tram cars, electric railways, and more.