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HV cable termination and cable support

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a10jp

Electrical
May 18, 2005
150
I have a question on HV able termination and want to consult others for their opinions. Being in Japan, we will have a switchgear equipment shipped from the US and where we have to terminate Japanese HV cable inside the cable entracne compartment. I am attaching a page from Schneider Elec Metal enclosed Switchgear, where it shows a simple diagram for cable connection.

What I am uncertain is because the cable is Japanese, so we have to use termination kit for Japanese cables. Being that said, the attached mfr cut sheet said that termination installer must use lugs suppled by Schneider Electric. That seems obvious. But what else, what other pitfalls I should be awared of, for example, are there typically any suppport for the cable inside the entrance compartment? I am amased the cable is only supported at the lug connection for all its vertical wieght, that can;t be, right? Yet, I cannot find anywhere else to hold this cable. The mfr has not responded to me yet, but I wanted to make sure I asked enough question to cover all angles because I am terminatng a Japanese cable inside a US equipment. Any other areas I should consider?
 
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The weight of the cable should not be supported by the lug. That is a recipe for disaster. Aside from gravity there are also short circuit forces and thermal forces that will either break something or loosen something over time. There should be a gland plate in the bottom of the cable box so you can install cable glands to take some, or all of the weight. You may also need additional clamps/cleats in the trench depending on how deep it is. Without the details of your installation its difficult to comment further, but you may be able to fix cleats to unistrut channels, or something simliar, mounted below the switchgear. If you have to use the Schneider supplied lug then you will have to ensure it is suitable for your conductor and termination. Normally the installer chooses the lug to suit the cable and termination, but it may be the design of this particular switchgear requires a specific lug.
Regards
Marmite
 
As Marmite already said, you have to chose the right lug for your cable [could be UL Listed, for instance, as Burndy YA302N or else] see: Also if you could calculate the short-circuit forces you would find a suitable cable clamp as id-Tecnik for instance. See:
Short circuit current calculation could be done according to IEC 60909 and the forces can be calculated according to IEC 60685-1.
The distance between phases and from live parts to grounded elements has to be at least as stated by standards. As an example is the minimum distance in a terminal box of a high voltage motor or generator as indicated by NEMA MG-1 cap.20 or as per
BS 154 see:
The cable terminating may be also Raychem or Elastimold product [or equivalent.]
 
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