According to IEEE 665 – section 220.127.116.11 page 27, it is important for the ground conductor to run as close as possible to the phase circuit conductors; since it will cause the fault current return path reactance to be reduced.
A design query on earthing trafo.
An earthing trafo installed on a 11 kv switchboard is rated for 381 kva , 11 kv/ 110v in a star - broken delta arrangement. A resistor rated 1.14 ohms is connected across the broken limb. ...
According to electrical basic design of one industrial plant, contractor shall supply suitable grounding transformer with an additional NGR in its neutral connection for limitation of ground fault current system to 400 A.
Recently we have carried out the periodic inspection in a manufacturing plant. This plant has a 6.6kv network supplying 3 remote buildings each with transformers. We found that the Zs readings throughout the installation in one of the buildings were high compared to previous inspection reports.
Any one can sugguest for neutral cable size for 75mva, 66/22kv, delta/ star)?.my neutral cable is connecting thro NGR value is 6.5 ohm. fault level is31.5kA. lv cable size is 3x(3x1c 630).provide sample calculation also.
What are the components used in providing an earth monitoring system in a hospital?Where else we need an earth monitoring system?How many types of earth monitoring systems are available?Give drawings and basics of each system.
How do i calculate the number ground rods for different grounding systems? is it possible to make only one grounding system for electrical, equipment, instrumentation and lightning protection grounding?