high voltage dc post, can't find anything over 48v dc

[SilverState]

My PV array is putting out ~240v and I need to connect the array's output to some large underground cables. Typically I'd use terminal posts to do that and put lug fittings on the solar output and lugs on the big cables, and connect them with the fasteners at the posts.

The problem I have is that everything I'm finding is rated for a max 48v DC. I think with the lug connectors touching each other on the post/stud there's not a lot of current elsewhere so I'm not sure where the rating is coming from. But exceeding the recommended rating by 5x seems a little risky.

Any suggestions?

 

[koppted]

You can use eriflex power distribution blocks to as splicers This one for example https://www.alliedelec.com/product/nvent-eriflex/569251/71532918/ is rated for 1000vdc at 400amps

 

[SilverState]

You can use eriflex power distribution blocks to as splicers This one for example https://www.alliedelec.com/product/nvent-eriflex/569251/71532918/ is rated for 1000vdc at 400amps

Thanks. Unfortunately my underground cables are 4/0 (huge, like the size of my thumb) hence why I was trying to put lugs on the ends and hook them into posts. It's just really hard for me to understand how 10 gauge wire is capable of supporting up to ~500v dc but these huge terminal bolts are not.

 

[OzSolar]

My PV array is putting out ~240v and I need to connect the array's output to some large underground cables. Typically I'd use terminal posts to do that and put lug fittings on the solar output and lugs on the big cables, and connect them with the fasteners at the posts.

The problem I have is that everything I'm finding is rated for a max 48v DC. I think with the lug connectors touching each other on the post/stud there's not a lot of current elsewhere so I'm not sure where the rating is coming from. But exceeding the recommended rating by 5x seems a little risky.

Any suggestions?

Your link is from a marine company so I doubt you'll find any of that stuff with more than 48v rating.

Sounds like a perfect application for a "Solar Combiner Box". It may take googling to find the one you need.

Some "Polaris lugs" in a Nema 3R box under the combiner box may be necessary.

 

[koppted]

Thanks. Unfortunately my underground cables are 4/0 (huge, like the size of my thumb) hence why I was trying to put lugs on the ends and hook them into posts. It's just really hard for me to understand how 10 gauge wire is capable of supporting up to ~500v dc but these huge terminal bolts are not.

That was just an example. But eriflex actually makes distribution blocks that will accommodate bigger than 4/0 cables. Like this one https://www.nvent.com/en-us/eriflex/products/efsud2c9c1250al
Btw, for the most part voltage is not affected by wire guage, but current ( to a certain limit). You could have 500vdc on 12guage wire as long as amperage is correspondingly lower.

 

[Warpspeed]

What you need are threaded insulators.
These come in various sizes from really small to really huge.
How about these fairly large ones, on e-bay right now....
Judging by the 5/8 thread, these look like they would just about fit inside a coffee mug. Very strong, excellent for high voltages.
And these particular ones are really cheap....
https://www.ebay.com/itm/224856844248

 

[Shimmy]

Thanks. Unfortunately my underground cables are 4/0 (huge, like the size of my thumb) hence why I was trying to put lugs on the ends and hook them into posts. It's just really hard for me to understand how 10 gauge wire is capable of supporting up to ~500v dc but these huge terminal bolts are not.

It is the lack of insulation. The multi-port connectors will work for your application and are the right tool for the job. They are availble in mixed-size ports as well, since they are commonly used for feeder taps.