Stress Cones/Voltage Grading Sleeves for 15kV Connections 1

[TheBlacksmith]

A little background. I am a ME, working on a new project with EE overtones. We are designing a new (for us) generator with a terminal voltage of 13.8kV. For design purposes, we have assumed a voltage grading sleeve length of 16 inches, with a 3-inch lug to connect to the generator. The output connection enclosure manufacturer has assumed a sleeve length of 12 inches, but is unable to provide the make or model number and we don't have room to enlarge the enclosure. While we have access to EE's, my boss wants me to be knowledgeable of the situation. So, does anybody know of commercially available 13.8/15kV stress cones? Not to be rude, but I don't need theory or calculations, I need manufacturers and part numbers. My company's conservative approach is that the part is only good for what the manufacturer will back it for, not what I or anyone else calculates it is good for.

Thank you in advance.

Blacksmith

 

[busbar]

Seek out a qualified splicing contractor to review your requirements on-site. Shielded cable terminations call for an experienced installer. Reduced dimensions will likely fail basic DC overpotential tests. Cable and termination manufacturers shouldn’t be expected to stand behind their products if they’ve been misapplied.

 

[TheBlacksmith]

Busbar - Thank you for your prompt reply. Perhaps I was too subtle in my request, I don't wish to reveal my employer. Suffice to say we have plenty of experienced installers, with much success at 4160 volts, and we only use approved procedures, developed in conjunction with the suppliers. It is myself, the ME being tasked with coming up to speed on this subject for preliminary design that seeks the information. Believe me, I have already learned enough about corona, tracking and insulation degradation to know that you don't actually perform 15kV installations in your backyard with instructions downloaded from the Internet. Whatever I learn here will be checked many times over before the first connection is ever made. I'm just looking for sources (makes and model numbers) of shorter stress cones to verify the claims of my enclosure supplier.


Thanks,

Blacksmith

 

[HydroChuck]

You might review 3M products. We are using their terminations for 11 kV.
See

http://www.3M.com/elpd

 

[busbar]

Plymouth Rubber and Kerite also make termination materials. Again, reduced dimensions will limit BIL ratings.

Generator termination failures have fault contribution from two directions—the local stator and the rest of the system they’re tied to.

 

[stevenal]

http://energy.tycoelectronics.com/ieee/start.asp

 

[BJC]

Call your local Raychen drummer. Here's their webpage or look up "Raychem 15 KV terminations" on google

http://www.raychem.com/products/epd/rrg/3-15.pdf

 

[jbartos]

Suggestion: Reference:
1. Grigsby L. L., "The Electric Power Engineering Handbook," CRC/IEEE Press, 2001
Reference 1 page 3-173 Par. "Capacitance - Graded Bushings"

 

[kraigb]

Thas already been covered fairly well, but I might as well add my 2 cents.
The recommendations made above regarding 3M and Raychem are where I would check first. Depending on the cable diameter, some of the 3M indoor terminations (the 7600 series) are under 12 inches, but I if your generator is large enough to require cables with greater capacity (anything larger than 4/0) then their terminations exceed your 12" limitation.

In the past, Raychem has been able to come up with some terminations for electrical testing that fit on remarkably short cutbacks, so they are also a good bet.

 

[jbartos]

Suggestion: Visit

http://www.chardonelectrical.com/terminat.html

http://www.bsescontracts.com/main.asp?clink=35msc#applications

etc. for more info