How i am going to drying 18 medium voltage cable 20 kv

[gelykeng1]

The problem is very simple. I put 18 20kv cables in a basement and after a big rain the base was full with water.
The cables as i search have for at least 10 meters moisture and water inside.
I want to save the cables but i donot know how without to cut them.

 

[waross]

Do I understand the the cables were not installed but were stored in the basement and the water entered between the cable strands?
A combination of heat and vacuum may work.
I would apply the vacuum simultaneously to both ends of the cable.
respectfully

 

[alehman]

From NEMA "Guidelines for Handling Water-damaged Electrical Equipment":

Any wire or cable product, not containing fillers, that is suitable for wet locations and whose ends have been exposed to water, may be considered a candidate for "purging" (using an
inert gas under pressure to remove water contained in the product) under engineering supervision. If this procedure is employed, the wire or cable should be tested prior to energization. As a minimum, an insulation resistance test with a megohmmeter should be conducted.

Any cable that contains fillers, such as polypropylene, paper, etc., should be replaced if the ends of the product have been exposed to water.

 

[gelykeng1]

the cables are already installed.
What did you mean by vacuum. I do not know if i damaged the cable when i applied a vacuum pump on it.
Do you know a procedure or where to find something relative.

 

[SteveHuck]

In my area there is a conpany that test's breakers and cable. One of the services they offer is to hook up dry nitrogen to the cable to dry out a cable and push out the water. Call around in your area and see if any of your local testing outfits offer this service.

 

[apowerengr]

Or try cable fluid injection technology. This has been discussed in prior threads.

 

[thewellguy]

I have used nitrogen to dry our cable. Just make sure you do it in a well ventalated area. The nitrogen and water produce laughing gasas the cable drys.

 

[gelykeng1]

thanks guys for your help.
tomorrow i am going to try with the nitrogen. i will let you know about the results.

 

[davidbeach]

If there is any likelihood of this flooding again you should give serious consideration to replacing all of your cable terminations with submersible terminations.

 

[BJC]

Nitrogen comes in many flavors, regular, dry, extra dry, oil pumped, water pumped and a few others..For cable de-watering I have always used Extra Dry.

On the exit end of your cable run the gas through a jar before blowing it out in the atomosphere. There are moisture indicators you can put in the stream.
The indicator I ahve used was a white material composed of small beads that turned blue if there was any moisture around them. When they stayed white it ment the water was out of the cable.

 

[itsmoked]

Any standard colored regenerateable desiccant could probably be used for monitoring.

Furthermore what you need is 'dry gas' not necessarily (possibly)dangerous nitrogen which can be a suffocating hazard. Most desiccant dryers can produce air that is extremely dry pushing -80F dew points and such.

You can use a standard air compressor an oil filter followed by a large desiccant dryer. Plumb this to the line and then plumb the other end of the cable into the jar as BJC mentions.

Put moisture tainted desiccant beads in the end jar and when they have been dried by the air coming out of the cable it's likely good to go.

Here's a example list of possibilities. (From the hip!)

Grainger

http://www.grainger.com

4ZL23 Coalescing Oil filter

4ZM18 Regulator

5P334 Flow meter

Mcmaster-Carr

http://www.mcmaster.com/

5163K22 Heavy duty dryer with sight window. (I can vouch for this unit.)

5163K48 Gallon can of desiccant beads. Turns pink when wet. Bright blue when dry.

I'd use the Coalescing Oil filter then the regulator then the desiccant dryer then a particulate filter then a flow gage to see what's actually happening then the cable.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[resqcapt19]

If the water is between the srands of the conductor and has not damaged the insulation, is it really any problem? A few years ago, I was disconnecting some 2.3kV service conductor terminations in a switchgear line up. The conductors were connected to the bus with "eye bolt" connectors and then taped up. We I removed the tape, about a pint of water drained out of each of the conductors. The other end was outside and terminated using the same type of connector with the bare end of the cable pointing up. There was no tape on the outside terminations. Over the years water had filled the space bewteen the strands with apparently no effects.
Don

 

[NewbieButTrying]

Was this non-shielded cable?

 

[gelykeng1]

Hi to everyone.
The customer gave me a free access to a tank of nitrogen (free from moisture) The results until now is very good. From each cable i take out at least one lt of pure water. now i am trying to take out and the moisture from the cables.
At the end of this i will propose to my customer to test the cables for dielectric strength of the insulation.
The type of the cables is CU / XLPE / CTS /PVC / AWA / PVC