HT Cables

3 comments

Rate

Anonymous Poster	HT Cables 03/02/2010 11:01 PM
	my question is this, in ht cables why used the simi conductor ofter insulation.if not use then what will happen , please explain me thanks
	Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

These comments received enough positive votes to make them "good answers".

Judge Commentator Join Date: May 2009 Location: West Point, Texas population around 200.Located between Austin and Houston Posts: 69 Good Answers: 2	#1 Re: electrical engineering 03/02/2010 11:47 PM
	Try posting again.Do not use the same words from the old post, in this new post.First we must determine what is being asked. Respectfully Joe in Texas __________________ We hold these truths to be self evident,one nation under God
	Reply

Anonymous Poster	#2 Re: electrical engineering 03/03/2010 12:23 AM
	in ht cables why used the simi conductor ofter insulation.if not use then what will happen Does not actually mean much. However let me guess. is it "In HT cables why a conductor (in fact a wire mesh or sheath) is used over the insulation, if not used then what will happen" ? These are cauled armoured cables. Check up the armoured cables in google and you will see the crossection. In brief, there is usually the (assuming 3 phase 4 wire) 4 wires having their own insulation, in colour usually. Over these there will be one insulation keeping allthe wires together. Over this there will be metal wire/ braiding. This is to give protection to the cable against mechanical damage. ensure it is rigid enough so thet you can not use a short bend and thereby stretch/ damage the insulations and also most usually this armour is connected to earth, which has several advantages, keeping the EM interaction with external minimum (shielding), quick identification/ isolation in case of insulation failure/earth fault, etc. This armour is then covered by the final sheath, which is usually waterproof, scratch resistant etc.
	Reply Off Topic (Score 5)

Khor Commentator Join Date: Sep 2009 Posts: 59 Good Answers: 3	#3 Re: electrical engineering 03/03/2010 1:10 AM
	In single core and 3-core HT XLPE cables,triple extrussion of semiconductor-insulator-semiconductor layers are coated almost at the same time ( in a single process ) on the copper or alluminium conductor.This will ensure that the three layers of material are in good contact to each other without air gap/bubbles. The purpose of the inner most layer of semi conductor which is in contact with the metal conductor is to "smoothern" the conductor and have stress control on the surface of the conductor.The XLPE is to insulate the cable to the rated voltage plus safety margin.The semiconductor layer on the XLPE layer is to conduct the capacitive voltage to ground.This is a very important requirement that is not understood by many.Without this layer and proper grounding at the cable termination,partial discharge and tiny arcing will occur along the weaker section of the cable and finally the cable will be damaged. Regards, Khor
	Reply Good Answer (Score 3)

These comments received enough positive votes to make them "good answers".

Copy to Clipboard

Anonymous Poster (1); Judge (1); Khor (1)

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (95 right now) Show Members