alaskannoob avatar image
alaskannoob asked

Is it okay to use Class K tinned copper 10 AWG PV wire with MPPT RS?

Looking for Class K PV wire to comply with the MPPT RS manual requirement for individual strand diameters in the cable. I found some wire that meets the requirement, but the individual strands are tinned copper. Is that okay to use?

Specs of the wire I'm considering using to plug into the MPPT RS:

Single Conductor Wire
10 AWG Orange
10 Foot Package


E196955 1676751935881.png AWM 10 AWG OIL RESISTANT 600V VW-1 ARCTIC ULTRAFLEX BLUE® -55°C TO 105°C CSA 234608 TEW 105°C 600V FT1

Rated for and proven in extreme temperatures of -55°C to 105°C

This highly flexible wire combines finely stranded tinned copper with a jacket that resists the abuses of oil, gasoline, sunlight, saltwater, acids, and chemicals. ARCTIC ULTRAFLEX BLUE®has high abrasion resistance and can be used in most 600V applications. UL Listed as AWM (Appliance Wiring Material). Numerous applications including those approved under NEC article 400 and associated articles.


  • Superior flexibility to -55°C (-67°F)
  • Class K fine stranded tinned copper construction
  • Resists oil, grease, chemicals, abrasion
  • Sunlight and weather resistant
  • Flame retardant (VW-1)
  • UL Recognized and CSA Approved
  • Environmentally safe
  • Made in the USA


  • UL 508A Industrial control panels
  • Internal appliance and equipment wiring
  • Inverter cables and wiring
  • Industrial machines and robotics
  • Construction equipment
  • Marine, RV and automotive wiring
  • Medium and heavy-duty trucks and trailers
  • Load banks, motor leads, welding cable
  • Forklifts and golf carts
  • Batteries and chargers
  • Power hookup cable

Manufactured exclusively
by Polar Wire Products


1676751935847.png-55°C to 105°C

Construction Specifications:

  • 10 AWG
  • Class K Tinned Copper Stranding (105/30)
  • .120" Conductor Outside Diameter
  • .030" Insulation Thickness
  • .180" Finished Outside Diameter
  • Ampacity at 30°C (86°F)*: 60
  • Ampacity at 40°C (104°F)*: 56
    *Ampacities of 600V and 1000V 105°C AWM wires in air. Ampacities based on single conductor in free air, 30°C or 40°C ambient temperature as specified, 105°C conductor temperature, per NEC table 310-17 (adjusted for 105°C). Free air ratings assume a one-cable-diameter space between adjacent conductors.
mppt rs
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3 Answers
klim8skeptic avatar image
klim8skeptic answered ·

Class K Tinned Copper Stranding (105/30)

Cable stranding does not meet requirements outlined on page 1 of the RS 450 manual.

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Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

alaskannoob avatar image alaskannoob commented ·


What requirement exactly does it not meet?

If I'm reading this chart correctly (which I may not be), Class K 10 AWG uses strands with .010" diameters which is less than the .016" diameter required by Victron on Page 1.

The strands are made of tinned copper. Page 1 of the manual requires they be made of copper (not sure if tinned copper counts but it seems to from what I've read on the discussion elsewhere).

The wire in question is "Class K Tinned Copper Stranding (105/30)" which is strands smaller than the 26 AWG listed on Page 1.

So I'm not sure what part of the stranding doesn't comport with the requirement.

Can you be more specific, or do you have an example of any PV wire that DOES meet this Victron requirement so I can compare notes?

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wire.png (508.4 KiB)
klim8skeptic avatar image klim8skeptic ♦ alaskannoob commented ·
I thought that the 105 referred to the # of strands, and the 30 was the strand diameter in thousandths of an inch.

I could be wrong though.

Are you no longer using the 7 strand PV cable?

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alaskannoob avatar image alaskannoob klim8skeptic ♦ commented ·

I'm not sure. Either way, that original wire isn't UL 4307 listed so it's not PV wire so I won't get it.

I found a new wire that will work for plugging into the MPPT (it's also tinned copper but everything I see suggests that is marine grade and better and nobody has told me here that the MPPT can't take tinned copper strands).

We're still planning on using the thousands of feet of 7-strand PV wire we bought, but we're going to have it connect via MC4 to smaller strands of the new Victron-compliant wire which will go into the MPPT.

Assuming we can ensure MC4 connector compatibility. If we can't, we'll have to order thousands of feet of new PV wire.

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alaskannoob avatar image
alaskannoob answered ·

Okay, the tinned copper in the OP is not listed as UL 4703. So it's not PV wire for whatever reason.

But I did find UL 4703 10 AWG PV wire that has individual strands of AWG 29 so I believe this wire meets Victron's requirements.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Alexandra avatar image
Alexandra answered ·


Tinned copper is technically a superior cable as it is more resistant to corrosion etc and the rest of the sales speel.

Tinned copper bus bars are available from Victron, so I dont think they are against tinnned copper.

What is also important is strand size as well and that is clearly stated. For PV must also be double insulated and meet local regulations.

So a combo of all would be awesome.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

alaskannoob avatar image alaskannoob commented ·
Well that's good since we just discovered that our MC4 connectors on our solar panels require tinned copper and not bare copper. So we'll have to replace our 3000 feet of 7-strand bare copper PV wire anyway.

I thought that would be one thing we could count on being simple. PV wire, check. Voltage rating, check. Ampacity, check.

But not so much. I'm just waiting to discover some manual that says "do not use solar panels for photovoltaics while the sun is above 1000 degrees C" next.

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klim8skeptic avatar image klim8skeptic ♦ alaskannoob commented ·
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alaskannoob avatar image alaskannoob klim8skeptic ♦ commented ·
I think perhaps I will just install an isolator in a box near each solar array. Then use that to transition from the correct tinned copper wire from the panel to my bare copper wire for the long run to the solar shed. At the solar shed have the bare copper wire go into a 2P circuit breaker and transition from the breaker into the Victron compliant PV wire into the MPPT.
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