Earthing

Electrical Earthing Systems - This excellent link from Wikipedia, the free encyclopedia is an excellent reference on electrical earthing and grounding. It includes information on Low-voltage systems, IEC terminology, TN networks, TT network, IT network, Safety, Regulations, Application examples, Medium-voltage system, Solid-earthed neutral and Unearthed neutral.

Earthing in Low Voltage Systems - Covers Earthing connections, Definition of standardised earthing schemes, Characteristics of TT, TN and IT systems, Selection criteria for the TT, TN and IT systems, Choice of earthing method - implementation and Installation and measurements of earth electrodes - from Schneider Electric.

Understanding Neutral versus Ground when applying RFI filters in Electrical Equipment Installations - The grounding of electrical equipment is probably one of the least understood aspects of electricity. As the characteristics of electrical equipment changes from linear to non-linear, the nature of grounding expands from the task of insuring the safety of personnel to insuring that one type of electrical equipment does not interfere with other types of electrical equipment. One point for confusion rests with the often interchanged terms of Neutral and Ground. Many articles have been written concerning the problems with 3rd harmonics overloading the neutral conductor. Many articles have been written concerning the problem of electrical ground noise. Even with all these articles, there still exists confusion concerning whether equipment should be connected to the neutral or connected to a ground. It may be possible that a simple rule would clarify the differences between Neutral and Ground. It can be stated that Neutral can be grounded, but Ground is not neutral. From Rockwell Automation.

The Following Excellent papers are from IDC.

• Reducing Copper Theft in Telecommunications and Electrical Industry - Rohit Narayan - ERICO - With the increase in copper prices, copper theft, which was once a nuisance factor, has now become a major problem for the telecommunications industry. Copper theft in the US alone has a cost impact in excess of US1 billion dollars per annum. Copper theft in the telecommunications and power sector includes the theft of ground bars, cables and grounding conductors. It is a significant problem in Australia and now extend to all the states - Thanks to IDC.
• Protective Earthing, Impacts, Myths and Verification Tests - Paul Lo - MIE Aust., Chartered Professional Engineer - Protective earthing is essential for electrical safety and power system reliability and stability. The effectiveness of protective earthing design and installation affects not only the adequate clearance of the life critical electrical faults, but also the power system reliability and availability. The ineffective protective earthing will lead to the potential hazardous ground voltage (potential ) rise during the ground fault and the prolonged ground potential rise (GPR) will have significant impact. Supporting diagrams can be found here.
• Best EMC Installation Practice for Variable Speed Drives - Understanding the Main Differences and Goals between Earthing and Bonding - Eduardo Gie - Technical Manager, Danfoss Pacific - Power Electronics - The application of variable speed drives (VSDs) or/ variable frequency drives (VFDs) are well-known for their benefits. They are energy efficient and flexible in the controlling of processes and machinery using standard AC or PM motors. Although many VSD’s can provide efficient control, depending on the design and installation of the VSD, they may result in increased problems elsewhere in the electrical system. When electrical noise problems arise, it can result in unreliable operation of other equipment, increased liability, increased project timescales and result in non-compliance with regulatory requirements. It can cause loss of revenue, since it can be a very time-consuming and a costly exercise to resolve them. This presentation highlights the recommended EMC best practice to avoid undesired Electromagnetic interference when installing VSDs in commercial and industrial applications.