Current Transformers And Its Factors

A current transformer is kind of electrical instrument, which is produced especially to provide a flow of current in the secondary circuit that is correctly perpendicular to the amount of current flowing in its primary circuit. To calculate current and monitor the operation of power grid Current Transformers are used widely and it is classically defined by its current ratio from primary to secondary.

Current transformers are most widely used in metering and protective relaying in the electrical power industry where they make easy the safest obligation of a huge amount of currents, regularly in the presence of high voltages on the circuit. The current transformer securely cut offs to measure and to manage a circuitry from the high voltage essentially available on the circuit. Current transformers are normally controlled by passing a single primary turn under a well-insulated toroidal core with enormous turns of wire wrapped. Current transformer is further used to measure the flow of current and as well in monitoring the operation of the power used. The CT is fundamentally defined by its value of current ration flowing from primary to secondary.

There are some factors that improve the current transformer’s accuracy. They are like burden, rating factor, physical CT configuration etc.

The value of impedance is the outcome for the burden in a Current transformer circuit. The basic items that are reasons for burden in current calculation circuit are intermediate conductors and switch blocks meters and the sources are the conductors among the meter and the CT. Further the problem of producing high resistance occurs due to placing a substation meter at some level of distance from meter that could beat by using current transformer with 1 amp that produce low voltage drop.

The Rating Factor of current transformers that are dependent on ambient temperature, is a factor used to determine the correct maximum measurable primary current by multiplying the full load of a CT. In order to maintain the accuracy level in rising of ambient temperature, the CT would have low capacity, and the rating factors of the CT’s would range from 35 degrees Celsius and 55 degrees Celsius.

Another important factor for accuracy of current transformer is Physical Current Transformer Configuration. If in case the conductors are not really centered in circular or oval, the inaccuracy occurs in CT and this needs to be notified for correct accuracy. Normally, the CT’s are constructed in many ways like passing a single primary turn by way of well-insulated toroidal core wrapped with many turns of wire. To calculate the waveforms of high frequency or pulsed currents within high pulsed power systems wideband current transformers are specially used.

By : Mr.Monish Mohan

What is an Electric Transformer?

Electric transformers are used to transform voltage from a higher voltage to a lower voltage. Electric transformers can transform alternating current from one circuit into another through electromagnetic induction. This generally consists of ferromagnetic core and two or more coils called windings. It can either be a single-phase or a three-phase configuration. You have to remember certain specifications when searching for electrical transformers. These include: maximum secondary voltage rating, maximum secondary current rating, maximum power rating and output type. Output choices include AC or DC.

Cores can be constructed as either toroidal or laminated. Toroidal cores have numerous advantages like they provide low magnetic leakage, low noise, close flux path and smaller core size/weight and efficiency. A laminated core is made up of sheets of magnetic material insulated from one another by an oxide or varnish. Laminated refers to the laminated steel cores. These steel laminations are insulated with a non conducting material such as varnish, and then formed into a core that reduces electrical losses. There are many types like autotransformer, control, current, distribution, general purpose, instrument, step-up and step-down. Mountings include chassis mount, dish or disk mount, enclosure or free standing, h frame and PCB mount.

The most important use of electric transformer is transferring electricity from power plants to homes and businesses. Electric transformer is usually of high voltage at the power plant. Voltage is little lowered when it reaches the substation. When it reaches a smaller transformer, voltage is reduced again. This is a continuous process, which repeats until the power is at a usable level. You have likely seen the type of electrical transformers that sit on top of electric poles. Most of the electrical transformers contain coils or windings that are wrapped around a core. The power travels through a coil. If there are more coils, voltage is much higher. If there are fewer coils, the voltage is low.

The way electrical transformers work has changed. Transformers have made life easier you can transfer power in a timely, efficient and more economical manner. Many people do not have their houses near a power plant. But it has an added advantage for both homes and businesses because the power plant is nearby then can obtain dependable, affordable electricity. Electricity that is used in homes and business places pass through electrical transformers and reach the end users. There are different types of electrical transformer like site, Portable, Low voltage, Enclosed, Panel Mounted, Three phase, Small Clamped, Inspection Lamp units and custom Electrical transformers.

By : Nisha Sabbik

How to Choose the Right Portable Generator For You

Before we get into choosing a portable generator, let's review exactly what a portable generator is, and what the standard uses for them are.

What is a portable generator? Typical portable generators are fueled by unleaded gasoline and have standard 120-volt power outlets like the outlets you have on the walls of your home.

What can portable generators be used for? Portable generators are extremely versatile and can be used for a wide variety of purposes. Among the most common uses of a portable generator are:

- Providing power for a home in an emergency

- Power in locations that do not have access to standard eletric outlets

- Recreational use, such as at campsites and in RVs.

How do I use a portable generator? When the generator is running, you simply plug in your tools or appliances into the 120-volt (standard) electric outlets. Some models of generators also have 240-volt outlets. 240-volt outlets are used for large appliances like clothes dryers.

Now, let's talk about what to look for when choosing the right portable generator for you.

How high of a power capacity do I need?
Generators use two basic power measurements: peak power (sometimes referred to as startup power), and continuous power. Both kinds of power are measured in wattage.

- Peak power is the required wattage that appliances need at startup or when they are running at their highest power consumption levels.

- Continuous power is the required wattage to operate appliances under normal circumstances.

What are standby generators? Standby generators are generators that create anywhere from 5,000 to 25,000 watts of power (sometimes even more). You need to choose a generator that supplies enough peak power and continuous power for the appliances that you need to keep powered.

What are you going to use your generator for? For recreational use, A small 1,000-watt portable generator could be all you will need. If you need to power tools at a remote jobsite, you could require up to about 8,000 watts of power.

Another thing to consider is how many outlets you will need on your generator. Make sure there are enough outlets to power all of the appliances you will be using at one time.

The size of the fuel tank is another consideration and is very important. Depending on how long you will potentially need your portable generator to run, you may need a larger fuel tank. The larger the fuel tank, the longer your generator will be able to run without refueling.

By : David Clair