Friday, February 19, 2010
Monday, February 15, 2010
at 7:48 PM
Sunday, February 14, 2010
At least 20 people have been killed in southern Nigeria after a 33kV power cable fell on their bus, police have said.Another ten people have been injured and taken to Hospital in the southern provincial capital of Port Harcourt in the Niger Delta region on Saturday.The victims died of severe burns and electrocution after heavy rains loosened the power lines around the area.The fatalities are expected to rise, police said Sunday. They also say that some of the casualties were passersby...
Friday, February 12, 2010
This is a generating station which utilizes the potential energy of water at a high level for the generation of electrical energy. It uses the gravitational force of falling or flowing water. They are located in hilly areas where dams can be built and large water reservoirs can be obtained. Hydroelectricity is the most widely used form of renewable energy. Worldwide an installed capacity of 77GWe supplied a total of 2998TWe of hydroelectricity in 2006. This was approximately 20% of the world's electricity and accounted for about 88% of electricity from renewable sources...
Monday, February 8, 2010
The reason is because...
at 7:05 PM
Thursday, February 4, 2010
A Switchgear is an apparatus that is used to switch, control and protect electrical circuits and equipment. It is essentially used with switching and interrupting currents either under normal and abnormal conditions. Switchgear is a term used to refer to combinations of switching devices and their interaction with associated control, protective and measurement systems.
They are designed to be able to clear safely any fault which may occur in the power system. They can range from domestic 240V to industrial supply of 11kV and 132kV.In industries they are used to supply current to motors, heating equipments and capacitors. There are normally two types of switchgear assemblies namely Outdoor and Indoor Switchgear assemblies. Outdoor assemblies are mounted in fenced areas and interconnected using air insulated bus-bars. Indoor assemblies are coupled together by the switchgear manufacturer http://goliath.ecnext.com/coms2/product-compint-0001366237-page.html within a metal enclosure...
at 9:37 PM
Monday, February 1, 2010
Characteristic Features of Synchronous Motors.
1. They run at synchronous speed. This machine will run at a constant speed which can be changed by varying the supply frequency.
2. They are not self starting.-The rotor and stator fields have to be excited by a separate D.C excitation voltage.
3. They can be operated under a wide range of power factors (whether lagging or leading).This is why they are used for power-factor correction in power systems that have loads containing lagging power factors.