Medium Voltage Cable inside water

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Sajid khan

Sajid khan

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Pakistan
What will be the effect on the cable characteristics if we leave 11kV XLPE/SWA/PVC Cable inside a trench where the water penetrates to the trench from the soil?

Regards


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Medium voltage cable is often underwater with no adverse effects.
Besides, water penetrates all trenches in the earth.
You ever looked in a MV vault? I have looked in them and saw the elbows underwater for a couple of months with no problems.

Common sense dictates to not pull the elbows while they are underwater. Especially energized…
 
Regular=a NEC defined cable for wet location.
See N.E.C.-2020
Table 310.4(A) Conductor Applications and Insulations Rated 600 Volts
No NEC approved cable type for submarine cable-in my opinion.
 
Julius Right said:
Regular=a NEC defined cable for wet location.
See N.E.C.-2020
Table 310.4(A) Conductor Applications and Insulations Rated 600 Volts
No NEC approved cable type for submarine cable-in my opinion.
Click to expand...

Submersible cable is of different construction usually used for submersible pumps than the Normal PVC jacked cable.


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See attached a technical specification for a 33 kV submarine cable.
 

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  • Technical Spcifications -33kv Submarine cable.pdf
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NEC recognizes MV cables as dry or wet location. For instance, see:
ARTICLE 328 Medium Voltage Cable: Type MV
328.10 Uses Permitted. Type MV cable shall be permitted for use on power systems rated up to and including 35,000 volts, nominal, as follows:
(1) In wet or dry locations.
NEC Definitions
Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
 
Julius Right said:
NEC recognizes MV cables as dry or wet location. For instance, see:
ARTICLE 328 Medium Voltage Cable: Type MV
328.10 Uses Permitted. Type MV cable shall be permitted for use on power systems rated up to and including 35,000 volts, nominal, as follows:
(1) In wet or dry locations.
NEC Definitions
Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather.
Click to expand...
Ok. I’m confused..
The OP wanted cable in a trench that gets wet.
When did it turn into submarine cable?
 
It is always a trap when the thread title it is not what the o.p. said.
The title: Medium Voltage Cable inside water
o.p.:11kV XLPE/SWA/PVC Cable inside a trench
Medium Voltage= NEC MV cable and it is not in water but in a trench, water filled [how much?]
However, it is not a NEC recognized cable but BS6622 . We have then to consult BS 6622.
In a manufacturer catalogue it is written:
Cables manufactured in accordance with BS6622 are designed to be installed in air or to be buried in free-draining soil. Consultation with the manufacturer is required for installation in other conditions.
 
Hv&Lv said:
Ok. I’m confused..
The OP wanted cable in a trench that gets wet.
When did it turn into submarine cable?
Click to expand...

Yes My question is originally for a normal MV
cable if left for a long time immersed in water. I am attaching a picture for reference.
Water is coming from the ground naturally.
d60d639cbcdae3875d8ab30d94c43ce0.jpg



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The one I posted is UL listed.
The NEC says cables must be listed
 
Sajid khan said:
Yes My question is originally for a normal MV
cable if left for a long time immersed in water. I am attaching a picture for reference.
Water is coming from the ground naturally.
d60d639cbcdae3875d8ab30d94c43ce0.jpg



Sent from my iPhone using Tapatalk
Click to expand...
The cables are like that in about every vault at one time or another.
The jacket is pvc.
 
Julius Right said:
It is always a trap when the thread title it is not what the o.p. said.
The title: Medium Voltage Cable inside water
o.p.:11kV XLPE/SWA/PVC Cable inside a trench
Medium Voltage= NEC MV cable and it is not in water but in a trench, water filled [how much?]
However, it is not a NEC recognized cable but BS6622 . We have then to consult BS 6622.
In a manufacturer catalogue it is written:
Cables manufactured in accordance with BS6622 are designed to be installed in air or to be buried in free-draining soil. Consultation with the manufacturer is required for installation in other conditions.
Click to expand...

@Julis ; the lines written under the title are quite clear…


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