Demand factor is the ratio of the sum of the maximum demand of a system (or part of a system) to the total connected load on the system (or part of the system) under consideration. Demand Factor is expressed as a percentage (%) or in a ratio (less than 1). Demand factor is always less than one.

The value of demand factor is usually less than 1. It is expected because minimum demand on the power station is generally less than connected load. The demand factor is vital in determined the capacity of plant euipment

Demand factor is a concept used in electrical engineering to measure the ratio between the maximum demand of a system and its connected load. It helps in determining the peak load requirements of a system, which is essential for designing and sizing electrical equipment and infrastructure.

Definition:
The demand factor is defined as the ratio of the maximum demand to the connected load. It is expressed as a percentage or a decimal value.

Explanation:
To understand the concept of demand factor, let's consider an example. Suppose a residential building has a connected load of 100 kW and a maximum demand of 50 kW. In this case, the demand factor can be calculated as follows:

Demand factor = Maximum demand / Connected load
= 50 kW / 100 kW
= 0.5 or 50%

This means that the maximum demand is 50% of the connected load. In other words, the electrical system needs to be sized to handle only 50% of the total connected load during peak usage.

Importance:
The demand factor is an important parameter in electrical system design and planning. It helps in determining the peak load requirements and sizing of electrical equipment such as transformers, generators, cables, and switchgear. By considering the demand factor, the system can be designed to handle the maximum load efficiently without overloading the equipment.

Factors affecting demand factor:
Several factors influence the demand factor of a system, including:

1. Diversity of load: If the connected load consists of a mix of different types of equipment or appliances, the demand factor tends to be lower due to the diversity of their usage patterns.

2. Time of usage: The demand factor also depends on the time when the maximum demand occurs. If the peak load is concentrated during a short duration, the demand factor will be higher compared to a situation where the load is evenly distributed throughout the day.

3. Load factor: The load factor is the ratio of the average load to the maximum demand. It is inversely proportional to the demand factor. Higher load factors result in lower demand factors and vice versa.

4. Type of consumer: Different types of consumers have varying demand factors. For example, residential consumers generally have lower demand factors compared to commercial or industrial consumers.

Conclusion:
The demand factor is a crucial parameter in electrical system planning and design. It helps in determining the peak load requirements and sizing of electrical equipment. By considering the demand factor, the system can be designed to handle the maximum load efficiently without overloading the equipment.