Contactors Classification Factor Essay

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Contactors are used to control electric motors, lighting, heating, capacitor banks, thermal evaporators, and other electrical loads. Utilization categories for contactors are defined by IEC standards and indicate the type of electrical load and duty cycle of the loads to ease selection of contactors.

Symbol (According to standard IEC 60617: S00218):

Construction:
A contactor has three parts. The contacts are the current carrying part of the contactor. This includes power contacts, auxiliary contacts, and contact springs. The electromagnet (or coil) provides the driving force to close the contacts. The enclosure is a frame housing the contact and the electromagnet.

Operating principle:
When current passes through the electromagnet a …show more content…

TASK 2

Understanding of Distribution Factors

1- Load Factor:
The load factor is defined as the average load divided by the peak load in a specified time period. It can be derived from the load profile of the specific device or system of devices. It is given by the following formulae:

Diversity Factor:
The diversity factor can be defined as the sum of the individual maximum demand to the maximum demand on the source. Proper understanding of diversity factor is vital in designing of switchgears and in the selection of transformers, feeders etc. The simultaneous function of all installed loads of a given installation never occurs in practice, i.e. there is always some degree of diversity and this fact is taken into account for estimating purposes by the use of a factor (ks).
This factor is defined in IEC60050 - International Electrotechnical Vocabulary, as …show more content…

The motor load factor is then 12/15 = 80%. The motor above may only be used for eight hours a day, 50 weeks a year. The hours of function would then be 2000 hours, and the motor use factor for a base of 8760 hours per year would be 2000/8760 = 22.83%. With a base of 2000 hours per year, the motor use factor would be 100%.

2- Maximum Demand:
Maximum Demand is the power consumed over a predetermined period of time, which is usually between 8– 30 minutes. The most common period of time, in the majority of countries, is 15 minutes.
Maximum Demand can be measured with a device commonly known as Maximum Demand Indicator (MDI).
Earthing and Types Of Earthing:
In electricity supply systems, an earthing system or grounding system is circuitry which connects parts of the electric circuit with the ground, thus defining the electric potential of the conductors relative to the Earth's conductive surface. The selection of earthing system has a direct impact on the safety and the electromagnetic compatibility of the source. There are two types of earths namely Protective Earth (PE) and Functional

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