1500V DC rated wire (350MCM)

slurry bowl

Howdy forum.

I am trying to find the right wire to go from a 1500V rated DC combiner panel to a disconnect. 
The only wire I can find in that high voltage is PV style wire with XLPE insulation. 
This style of high gauge PV wire's insulation is outdoor rated, but we are running our wire protected and inside conduit for its full run
so we could use something not outdoor rated. 
I can find some options in the Medium Voltage market, but it is very expensive.
It does not have to be 350MCM and could be AL or CU if we could find some size options.
Any vendors recommended or insights?
thx.

Dave Angelini

I will ask some commercial installers I know. First though, is the disco also rated for 1500vdc?

BB.

One thing to look for... Insulation is usually rated for AC voltage... To find the DC rated voltage use the sqrt(2) as a conversion factor for Peak VDC of an RMS voltage AC waveform (this has been accepted for hipot testing of insulation/equipment where AC voltage and filter capacitors would "fail" a hipot test of equipment/power supplies). For insulation testing (as I recall), insulation is factory tested at 3x rated value (600 VAC rated insulation tested at 1,800 VAC):

• 600 VAC wiring * srt(2) = 845 VDC rating
• 1,500 VDC rating / srt(2) = 1061 VAC rating
• 1,000 VAC rating * srt(2) = 1,414 VAC rating

So--If you really only need 1,400 VDC rated insulation, 1,000 VAC rated insulation would do it.

-Bill

Dave Angelini

Meggers and Hi pot tests! I was just wondering if his disco is rated at 1,000vdc, like many are then, what is the need for 1500vdc?

I see his point as the cable below, one is paying for UV and direct burial. I have used it and it is pricey! 

https://www.generalcable.com/getattachment/NA/US-CAN/Information-Center/technical-information/Specification-Sheets/RENEWABLE-ENERGY/SunGen-Global_01_18.pdf

slurry bowl

Thanks for the feedback everyone.

Yes the DC Combiner is rated for 1500V and there are 1500V Disconnects also available.
https://images-96-8.imostatic.net/pdf_catalogues/documents/nesoh_1___solar-range-brochure.pdf

I appreciate the insights into AC/DC conversions BB. thank you.

We are using SMA 125 Peak 3s that require the DC combiner panel ahead of the inverter, but not a disconnect.
thanks

slurry bowl

This is the 2000 Volt rated PV wire I ended up using, FYI.