Technical Articles

Page 1 of 9712345»102030 Last »

4 Essential Features of Transformer On-Load Tap Changer (OLTC)

Done on the HV winding On-load tap changers (or circuit tap changers), as the name suggests, permit tap changing and hence voltage regulation with the transformer on-load. Tap changing is usually done on the HV winding for two reasons: Because the currents are lower, the tap changer contacts, leads, etc., can be smaller. As the […]

Read More

Miniature Circuit Breakers (MCBs) For Beginners

Dual functions of a switch and a fuse This technical article focuses on the widely used miniature circuit breakers rated for 240 V or less. These are smaller and lower-rated versions of industrial-grade molded-case circuit breakers rated for 600 V or less. These miniature breakers, called air circuit breakers, are based on thermal, magnetic, or […]

Read More

Sizing a Static UPS System In Data Center

UPS system serving a data center Choosing the power of a static UPS system serving a data center is a decision that involves various elements and which cannot be made before, or independently from, the choice of distribution scheme. The main elements to consider can be summarised as follows: Two from the following parameters of the […]

Read More

An Example Of Transformer Overload and Short-Circuit Protection

NEC Article 450 // Transformers Vaults Transformer protection consists of both overload protection and short-circuit protection. Overload protection is usually accomplished via proper selection of the secondary overcurrent protective device. NEC Article 450 gives specific primary and secondary overcurrent device ratings that may not be exceeded. These vary depending upon the accessibility of the transformer […]

Read More

HVDC VSC Technology For Offshore Wind Farm Applications

Offshore Wind Farms The demand for the power is increasing day by day. The only one solution for this is to use the renewable sources of energy like wind, solar, water etc. Among this wind can produce major amount of power. Since the wind farm requires a lot of space and adequate amount of wind, […]

Read More

Inspection, Test and Measurement Procedures for LV and MV (up to 36kV) Switchgears

Importance of checks and maintenance Installed in clean, well ventilated or air-conditioned locations, switchgear will require little routine maintenance. Major inspection should be scheduled for power plant shutdowns and concentrate for low voltage switchboards on identifying contact wear, correct operation of interlocks, correct overload settings and fuse sizes, signs of overheating, and undue dirt or corrosion. For MV […]

Read More

The Most Common LV/MV Motor Starting Devices

Two-state ON-OFF device The most common motor starting device is the low voltage motor-starting contactor. A contactor is defined as “a two-state ON-OFF device for repeatedly establishing and interrupting an electric power circuit.” Contactors are designed for optimum performance and lifetime when switching loads; they are not designed for interrupting short-circuit currents and therefore motor circuits require separate […]

Read More

The Consumer Power Substation With Metering On Medium Voltage Side

Nominal voltage 1kV – 35kV A consumer power substation with metering on medium voltage side is an electrical installation connected to a utility supply system at a nominal voltage usually between 1kV – 35kV, which for example may supply a single MV/LV transformer (exceeding generally 1250 kVA), several MV/LV transformers or one or several MV/LV secondary […]

Read More

Cooling is essential for long transformer life

Pushing loads over design limitations As you already know, cooling is really essential for long transformer life. Most transformers are designed for 55°C or 65°C rise. Using newer insulations such as Nomex, temperatures of 95°C and higher can be achieved. These temperatures can only be maintained if the transformer operating conditions do not exceed the […]

Read More

4 Types of DC Motors and Their Characteristics

Characteristics As you already know, there are two electrical elements of a DC motor, the field windings and the armature.The armature windings are made up of current carrying conductors that terminate at a commutator. DC voltage is applied to the armature windings through carbon brushes which ride on the commutator. In small DC motors, permanent […]

Read More
Page 1 of 9712345»102030 Last »


Subscribe to Weekly Download Updates //
(free electrical software, spreadsheets and EE guides)

EEP's Android Application
Electrical Engineering Daily Dose
Daily dose of knowledge and news from
Electrical Engineering World