Waterproofing XLPE Cables

[WhiteyWhitey]

Hi all,

I am working in Australia on a Transmission Cable job and we are having difficulty finding suitable end caps to waterproof the cables after installation.

The cables are 2500mm2 and 168mm in OD so the heat shrink products are not very readily available.

Can anyone suggest a supplier for products of this type?

Alternately, we have decided that using the following method should be sufficient to waterproof the cables before jointing. I was hoping that someone who had experienced the same problems with water proofing could critic our method.

1. Apply Heat shrink tube with approx 300mm after end of cable that is to be folded over the top of the cable during heating.

2. Apply 2 Layers of half lapped Self amalgamating putty type N-Tape to the bottom of the heatshrink tube and the point where it is folded over.

3. Apply Layer of half lapped duct tape (C Tape) over N tape.

4. Apply second heat shrink tube over the folded heatshrink tube.

5. Apply Ntape and C tape at each end of second tube

6. Apply Plastic wraping and more duct tape as necessary.

Please see attached file of the finished water cap.

What are your thoughts?



Thank you kindly,

Andrew

 

[davidbeach]

I guess I'm at a loss as to what you are trying to accomplish. Are you trying to prepare a cable for indefinite storage in a vault between installation and termination? In the normal sequence of installation, the loose ends are not in the vault long enough between installation and termination - a few days at most - to worry about water ingress. There will be some water ingress, but it won't go as far as the amount of cable to be cut off prior to the installation of the termination kit.

 

[WhiteyWhitey]

David,

Thanks for the quick response.

The cables will be in the joint bay in outdoor installation for approx 1 month between pulling and jointing.

The concern is that will any rain the joint bays tend to fill with water. While there will be dewatering done during the interval the atmospheric moisture and any incidental contact with the cable requires us to install water capping.

The joint bay will not be backfilled and the cables will be elevated.

Thanks,
Andrew

 

[alehman]

At the risk of asking the obvious, have you consulted the cable manufacturer?

 

[WhiteyWhitey]

I am working for the Manufacturer on turn key basis.

We have be given the go ahead from engineering but I wanted a second opinion for my own education.

Cheers.

 

[stevenal]

http://ecommas.tycoelectronics.com/...wing383008CpdfEnglishENG_CD_383008_C.pdf

 

[7anoter4]

See:

http://gzkaiheng.net/topic.php?channelID=21&topicID=165&action=product&productID=112

order Ref.Number:
KOSOO EC-200/90 
May it will be useful.

 

[WhiteyWhitey]

Hi!

Thanks for the responses.

The OD of the cable is 168mm none of these products can accommodate this large cable.

Hence the reason for the silly looking hunk of heat shrink.

I was just hoping there was someone around who had had to seal up a cable in the absence of heat shrink caps and had some tips.

Cheers,
Andrew

 

[stevenal]

Just because we didn't find the right size on the net doesn't mean it doesn't exist. Sounds like you found suitable heat shrink. Speak to the manufacturers.

Or mill a plastic dowel to 168mm to place under the heat shrink, making your own cap.

Rather spendy installation to trust to duct tape.