Advanteges of XLPE Insulation in Power Cables?

Xlpe - "expanded low-density polyethylene".

This material has a lower dielectric strength than PVC and will make sponge-like structures in a way that PVC can't. It is often found as the insulation and spacing material in coaxial cables intended for radio-frequency use. Its presence significantly lowers the characteristic impedance of the cable at these frequencies compared to PVC; ask any 'radio ham'.

Perhaps its properties mean that a lower thickness of insulation can be obtained in power cables, saving space and weight compared to PVC?

The 'x' in XLPE means cross-linked!!

Do you know so little?

Do a bit of research before posting comments about something you know little or nothing about.

Basically XLPE allows a higher current rating to be achieved in power cables, basically by the insulation being rated to 90 degC (from memory) instead of the standard 75 degC. There is some benefit with a slight reduction in insulation thickness and strength over standard PVC.

XLPE stands for cross linked polyethylene which is mechanically strong and gives better protection mechanically.Specifying a power a cable again is a detailed subject and one need to know lot of factors.

Another 'too-general' question...many answers depending on specific scope of the problem (voltage, current, environment/climate, even end-use of the cable..).

There are tons of books because it's a big, complex subject.

For instance...the answers you've gotten here regarding XLPE's advantages are more or less correct, but one charactersitic that hasn't been mentioned is that XLPE is hydrophilic (not a desired quality in high voltage electrical insulation), making it a major headache for mfrs - and providing subject matter for (probably) hundreds of Masters' and PdD theses over the years.

Good luck

RF guy is correct on XLPE cable. The cable has a high failure rate because of "treeing" which is when moisture penetrates the cable and causes a reaction that breaks down the insulation. When seen through a microscope the failing insulation looks like a "tree", or to some a spider web, in the insulation. The cable can be injected to extend its operating life.

Injected with what?

Traditional paper insulated cables suffer from the same problem so what is your solution, Einstien?

I take exception to this question.

1. Logged on as a guest - can you not be bothered to register? Or care?

2. Please and thank-yous are not good manners - they are mandatory. You are dealing with professionals. Act the same way or don't bother.

3. If you want information that you can't find with a simple Google or Wiki, you must be aware of what you are asking. Else, buy a book.

XPLE stands for crossed-linked polyethylene.

as said before , it has a higher temperature withstand capability and hence will generally carrry a higher current rating.

Your question was vague in terms of what kind of power cables are you interested in: low voltage i.e. 100o V and lower ot for high voltage power cables in the order of 12Kv to 132KV .

The issues are significantly different.

At low voltage , I have not seen any significant issue with XPLE.

But at high voltage , I have had many problems having to replace 69KV underground power cables . It is hydrophilic and can form water and volteage stress trees which cause cable failures.

The construction of the low voltage and high voltage types are also significantly different.

The low voltage will have a conductor insulation which is XPLE and an overall jacaket which may eb XLPE or PVC.

In high voltahe cables , you will have stranded compact copper with almost no airspace between strands to eliminate partial discharges and corona.

The next payer is usually semi-condictor material which looks like rubber approx 1 mm for a 69KV cable.

Next layer is the XLPE insulation with a dielectric strength of approx 10KV per mm of nsulation.

The next layer is semi-conductor material again.

on the semi-con you will have a mettalic spiral copper armour or a spiral copper tape .

the next layer is optional and it involves a water detecting layer which looks like fabric treated with a hydrodetecting chemical.

If the outer jacket of the cable is breached and you have moisture ingress, the hydrodetecting layer absorbs the moisture/water and bulges as an indication of the breach.

The last layer is usually UV resistant PVC or thermoplastic depending the intended installation .

Hope this helps.

Hello

I have answered your Post/comments,

Generally best to use the Cable Maker of your particular cable, but try:

http://relemaccables.com/

If you are still needing help, reply with

Kind Regards....

Hello fellow engineers. I am trying to do some cable sizing for a project. The cable will be used in a low voltage (380V) application. Now based on the numbers I had for amperage (300A) I naturally went to my trusty NEC to determine what size cable I needed. Looking at the table on page 297 I didn't see XLPE as a type of insulation to choose from. Now tried to do some research on XLPE and read somewhere that it has the equivalent temperature rating as RHH or RHW-2 (90 degrees C). However I was wondering if there was some reference as to whether this was true or not. Thanks in advance.

Contact Prysmian or NKT to get cable sizes and ratings.

I would use 35mm2 copper 3 phase XLPE insulated service cable (available from above).

In order to prevent the penetration of moisture and also to extend the duration of life, the XLPE insulated medium voltage cables are designed with longitudinally waterproof shielding including an additional swell tape and PE outer jacket. Cable Suppliers