Splicing PV 600v Cable to Thwn Cable.

[harborrick]

What are we using to properly splice THWN to 1k PV Cable in J Boxes? Or what is proper way ?

Thank You in advance

 

[jaggedben]

What's the actual system voltage?

 

[LarryFine]

What's the actual system voltage?

And current/conductor size? Why not regular wire-nuts?

 

[ggunn]

What are we using to properly splice THWN to 1k PV Cable in J Boxes? Or what is proper way ?

Thank You in advance

If you don't need the 1kV wire, why use it at all? If you need it on the roof because of DC voltage, you need it all the way to the inverter. Either way, I don't see the reason for the splice. That said, a splice between them is no different from any other splice.

EDIT: Your thread title says 600V PV wire.

 

[jaggedben]

And current/conductor size? Why not regular wire-nuts?

'Regular' wire nuts aren't rated for more than 600V.

Buchanan splices are a common preference in the solar industry. They seem to be more reliable in NEMA3R boxes on the roof.

 

[ggunn]

'Regular' wire nuts aren't rated for more than 600V.

Buchanan splices are a common preference in the solar industry. They seem to be more reliable in NEMA3R boxes on the roof.

His thread title and his question are contradictory about voltage. If his DC voltage requires 1000V wire he should not be splicing it to THWN at all. If it doesn't, then wire nuts should be OK.

 

[harborrick]

What's the actual system voltage?

600 DC Max

 

[harborrick]

And current/conductor size? Why not regular wire-nuts?

#10 and #8 PV cable at 600v DC

 

[harborrick]

What's the actual system voltage?

Pending on sun. Usually 400 to 500 volts .

 

[harborrick]

'Regular' wire nuts aren't rated for more than 600V.

Buchanan splices are a common preference in the solar industry. They seem to be more reliable in NEMA3R boxes on the roof.

I am being told that DC conductors should be a straight thru splice. That if I use a small Polaris ,it would heat up.

 

[ggunn]

I am being told that DC conductors should be a straight thru splice. That if I use a small Polaris ,it would heat up.

I don't know why that would be; did whoever told you that tell you why?

 

[harborrick]

I don't know why that would be; did whoever told you that tell you why?

he told us DC runs in one direction and that a Polaris rated for voltage would overheat. I have seen one of our Polaris heat up and that could of been with a bad termination.

 

[LarryFine]

High-frequency AC is more likely to have issues with sharp angles than DC is.

 

[Joethemechanic]

THWN

THWN is only rated 600v, If you can use that wire, you can use a 600v rated termination

And whoever told you that you need a straight through splice for 600v DC is a poopy head

 

[jaggedben]

he told us DC runs in one direction and that a Polaris rated for voltage would overheat.

I'm gonna be blunt: That's nonsense.

I have seen one of our Polaris heat up and that could of been with a bad termination.

Yeah stuff happens. It is usually due to installation error, manufacturer defect, or too much ambient heat. In my experience.

I would use Buchanan splices caps with insultors. It's how I was trained and they're the one thing I've yet to see fail.

 

[BackCountry]

I'm gonna be blunt: That's nonsense.

Yeah stuff happens. It is usually due to installation error, manufacturer defect, or too much ambient heat. In my experience.

I would use Buchanan splices caps with insultors. It's how I was trained and they're the one thing I've yet to see fail.

We switched over to using the 1000v rated yellow and red wire nuts from Ideal. They’re expensive but they work great.

Clearly in this case a regular wire but would be fine, but the 1000v versions do make a nicer connection.

Do you use the four way crimp Buchanan tool? I lost mine.

 

[letgomywago]

We switched over to using the 1000v rated yellow and red wire nuts from Ideal. They’re expensive but they work great.

Clearly in this case a regular wire but would be fine, but the 1000v versions do make a nicer connection.

Do you use the four way crimp Buchanan tool? I lost mine.

Those wirenuts are comfortable to work with also I like them for regular uses also

 

[BackCountry]

Those wirenuts are comfortable to work with also I like them for regular uses also

Those wirenuts are comfortable to work with also I like them for regular uses also

I would if I could find them! I found a box and then wasn’t able to get any more stock at our distributor

 

[letgomywago]

I would if I could find them! I found a box and then wasn’t able to get any more stock at our distributor

Both big boxes have them stocked and platt was promoting them idk if they still are. Next best for comfort I think are the 3m red yellow with the boot on the end kind of the same type of product but less wings

 

[jaggedben]

...

Do you use the four way crimp Buchanan tool? I lost mine.

Yes that's the only legit way to use them.