Lug Voltage rating 2

[tulum]

Hey Folks,

Does anyone know why cable lugs have a voltage rating? Bare copper bus bars do not.... and that is all a lug is?

I would assume it is for tracking distance to the insulation....

However, I am unclear as the use of 600V lugs at 15kV is common practice in industry.

Regards,
TULUM

 

[rovineye]

The few of my data sheets that do list a voltage rating all list 600 to 35kV. See the link to Scotchlok. T&B is the same on my glossy sales brochure, and Burndy is silent. I don't have any Sqr D info.

 

[MAGTiger]

For the lugs we use, the UL standard they are listed to has a scope of 600v. Some people here thought it was due to sharp points on the lug causing voltage stress areas to other components. I think it is simply UL needing a number and they are really hung up on 600v.


Neil

 

[PHovnanian]

I think MACTiger is on the right track.

Components need to be approved for a certain use. And that use includes an applicable voltage rating. While a 600V lug might be identical to a 15KV lug, the latter is most likely distributed as part of a termination kit which includes the requisite stress cones.

 

[rovineye]

Quite true. My termination kits do specify the lugs that can be used, even when not supplied as part of the kit.

 

[ArcFlashTraining]

I agree with PHovnanian in that the components need to be approved for a certain use as voltage rating.

http://www.arcflashtraining.net

http://www.arc-flash-training.com

 

[mcgyvr]

and compression lug manufacturer worth their weight in salt should be approved to up to 35kV.
We use Panduit lugs across the board. All are rated to 35kV.

 

[tulum]

Anyone have experience with mechanical lugs at 15kV? We have alot of gear with mechanical lugs that are 600V rated used at 15kV- most from along time ago....?

 

[PHovnanian]

tulum, those 600V lugs should be OK at 15KV as long as the cable has been properly terminated. Basically, this means stress cones, proper shield grounding, etc. The lug part isn't a big deal, voltage wise.

The 600V rating is just there to keep someone from throwing a lug alone on 15KV cable without taking the other necessary steps. The 15KV termination kit may have approved the use of the 600V lug by part number. Or the lug may have been specified under the ever popular 'engineering judgment' loophole in applicable codes.

 

[tulum]

Thanks Phovnanian....

 

[potteryshard]

I suspect that the listed voltage "rating" reflects more the level the manufacturer has tested at than what it is intended to be limited to...

 

[busbar]

See

http://www.tnb-canada.com/en/catalogues/online/industrial_MRO/pdf/c3/05en.pdf

page 1 “Two-Hole Lugs – Standard Barrel Certified to 600V and Recommended up to 35 kV”. My understanding is that the >600V application is to facilitate taping; but otherwise identical.