Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

ywhic · June 2012

Anyone on here utilize 10/2 or 12/2 'landscape' wire for there PV array??

I'm doing 3 short runs of under 15' and 2 runs of 10' and thinking 12/2 landscape wire would be fine..
and 100' of it is like $40 from lowes.. I'll only be using 65' feet total..

My panels are rated 18v and 8.05 amps..

The 10/2 is like $85 for 100 ft and has to be ordered online..

Both options would be put under the dirt by about 6" (its UV and waterproof)

The losses look like (using powerstream website and 12v option)

12 AWG 15 feet = 3.27%
12 AWG 10 feet = 2.18%

10 AWG 15 feet = 2.05%
10 AWG 10 feet = 1.37%

Opinions..??

The Only Sarge · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

I have not utilized it for solar PV. I have utilized many many yards of it for landscape lighting.
My only observation is that is does "corrode" rather quickly either buried or not.

Now granted this is with those "squeeze on" connectors for the landscaping lighting.

If one used proper connections maybe that would not be an issue. I do not know if there is a difference in alloy (tin/aluminum etc.) makeup from a wire made for one thing versus a wire made for another. As for the amps/loss etc. I remember all my 12/10 AWG landscaping wire said was 'not to exceed 150 volt" IIRC

I probably did not answer anything but hope my observations may be of some help.
I can tell you Home Depot and Lowes have excellent 8 AWG two conductor wire that is UV rated and about $0.28 per foot.
You can look at landscaping wire and it is "aluminum colored" and other wire and it is "copper colored". Now I do not know what exactly this means nor it's effect on resistance, longevity etc. Just throwing it out there

Cariboocoot · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Some generic wire info.

Most all wire is copper. Some appears to be silver or aluminium coloured; this is tinned copper. As a rule, aluminium wire is only found in larger gauges these days where its lighter weight makes up for it being a giant pain-in-the-anatomy to deal with (corrodes easily unless proper connectors and anti-oxidizing compound is used). They used to sell aluminium for house wiring, but as far as I know it has been banned (this may not be the case everywhere) because of the connection problems causing arcing and fires.

As far as gauge is concerned 8 AWG is 8 AWG, et cetera. There is some fudging of this in the automotive sector, but generally this is not an issue.

Beyond that the differences are in the insulation. Wire rated for 600 Volts has insulation capable of preventing that much Voltage from overcoming the resistance of the insulation and arcing to the next strand. Wire rated for UV exposure can be used outside without conduit. Wire rated for burial can be put directly underground without conduit. Et cetera. As long as all the wire's specifications meet the needs of the application it can be used.

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

The Only Sarge wrote: »

I have not utilized it for solar PV. I have utilized many many yards of it for landscape lighting.
My only observation is that is does "corrode" rather quickly either buried or not.

Now granted this is with those "squeeze on" connectors for the landscaping lighting.

If one used proper connections maybe that would not be an issue. I do not know if there is a difference in alloy (tin/aluminum etc.) makeup from a wire made for one thing versus a wire made for another. As for the amps/loss etc. I remember all my 12/10 AWG landscaping wire said was 'not to exceed 150 volt" IIRC

I probably did not answer anything but hope my observations may be of some help.
I can tell you Home Depot and Lowes have excellent 8 AWG two conductor wire that is UV rated and about $0.28 per foot.
You can look at landscaping wire and it is "aluminum colored" and other wire and it is "copper colored". Now I do not know what exactly this means nor it's effect on resistance, longevity etc. Just throwing it out there

Couldn't find 8/2 on there websites.. I may have to wonder thru next week and see what they got hanging on the spools..

Cariboocoot.. do you think the $40 warrants the 1% loss difference between the 10 and the 12??

Cariboocoot · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Al; the loss is a loss in Voltage only on a PWM controller. You have a bit of "extra overhead" with 18 Vmp panels. The 3.27% V-drop would bring them down to about the "ideal" 17.5 for a "12 Volt" panel. This also only occurs at maximum current, which will not be all the time. I would not worry about it for 15 feet of wire @ $40 more money.

One note about UG rated wire: it's the devil to strip. Just thought I'd warn you.

dhsola · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

I suppose you could double-up on your wire, that is, run two sets of that "'landscape' wire". I did using this wire from NAWS.....

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Cariboocoot wrote: »

Al; the loss is a loss in Voltage only on a PWM controller. You have a bit of "extra overhead" with 18 Vmp panels. The 3.27% V-drop would bring them down to about the "ideal" 17.5 for a "12 Volt" panel. This also only occurs at maximum current, which will not be all the time. I would not worry about it for 15 feet of wire @ $40 more money.

One note about UG rated wire: it's the devil to strip. Just thought I'd warn you.

Stripping my 5' test leads of 10 TUV SOLAR wire was interesting also with the double casing on it.. thanks for the warning.. I'll see what happens when I get out to the stores.. and see if they got anything on the spool's by the foot.. maybe I can get a good outdoor rated 10/2 that way..

Vic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

As,

Know that the budget is important.

This wire is 60 degree C rated for outdoor use (only). It cannot and should not be used with any part indoors. The Southwire (a brand carried by Lowes) data is here, as skimpy as it is:
http://www.southwire.com/products/LowVoltageLandscapeLightingCable.htm

If this system was going to be inspected, am almost certain that it would not pass. Realize that you may not be running this wire into your residence (perhaps into a shed ?), but ... and that you may not be using it in an insured structure and so on ...

At least this stuff is stranded, and it says that the conductors ARE copper -- both good. And, Southwire may not be the exact brand that you are looking at and so on, but 60 degree wire exposed to some sun in TX (for part of the run, probably), may not be a great combination, so be careful.

You will have a combiner box, and you could make the transition from the PV conductors supplied with the PV modules to THHN or similar Building Wire in conduit there perhaps, and not spend too much more $$. Of course, the PV leads may not quite reach the combiner with the 5-6 modules that you are considering ... YMMV Vic

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

I measured the leads I will need..

2 10'ft

2 panels 5-6 feet from rear of structure and wall where combiner box will be inside..
(gotta have walk room behind the building for maintenance and such)..

3 15'ft

3 panels 9-10 feet from rear of structure and wall where combiner box will be inside..

Also.. 60C is 140F

I don't understand the issue with 140'F.. my max temp in my region last year was 107F..

It will also be buried (about 4-6" deep from wall to under the panel area (shaded by the panel itself).. the only exposed section will be thru the wall on the back side of the cabin.. for about 8" or 9" to get it into the ground.. the other end of each run into the cabin will be limited to 4' up the wall to the combiner box..

My combiner box is for indoors only (indoor load panel).. so putting that outside isn't going to happen..

No inspections where I am at.. no insurance on the building.. its just a big 12x24 shed at the moment..

The 10/2 wire (90'C rated) from NAWS for $0.90/foot is good.. but for 70' and $14 sh to me.. it puts it higher ($84) than the BELOW option..

The last option is spring the $83 for real 10 AWG solar wire for 150' I found online from a solar store.. and just make my runs with that.. 2 entire separate single wire runs.. (which is abit messy IMHO..)

Vic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Al,

All of what I said above is just nit picking. The 60 degree C wire should be OK for thermal issues ... but in direct sun at 107 F ambient, could technically exceed ratings for the cable. At 107 F the Ampacity of the cable is about 21 amps, at 123 F, the ampacity is about 12 amps from the table.

The specs on the landscape wire are almost nonexixtant ... but this cable is not really rated for this service nit nit ..

I bet that it is not rated for indoor use (it DOES say "Outdoor") -- do not see the Fire Retardant VW-1 rating in the specs for the LS cable and so on ... nit nit .. nit.

I've done a number of things that are not Code Compliant ... have done other things that are not compliant, and I do not even know what those things are.

Just be careful, and use all of the fuses/circuit breakers with the correct ratings in all the needed spots. DC arcs can/do get ugly, and often need to burn clear (arc until the circuit opens). Conduit can be an inexpensive additional layer of protection.

Direct Burial cable often uses Polyethylene insulation which can burn, is fairly often eaten by rodents and so on. Just about done picking. Have Fun with the new project! Vic

Jim45D · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Please beware. Here today at my location the ambient temp. was 104° in the shade. The steering wheel (black) in my car was 127°. There is a differance between ambient temps, and direct sunlight exposure. At least shade that small portion of exposed 9 to 10" of wire at the back of your cabin. A simple wood enclosure will do the trick. Leave air passages in the sides.

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Jim45D wrote: »

Please beware. Here today at my location the ambient temp. was 104° in the shade. The steering wheel (black) in my car was 127°. There is a differance between ambient temps, and direct sunlight exposure. At least shade that small portion of exposed 9 to 10" of wire at the back of your cabin. A simple wood enclosure will do the trick. Leave air passages in the sides.

If I go with the 60C wire I will take extra care.. still up in the air on my direction.. I've been doing OK with sticking to proper codes and such pretty much.. I'd rather not risk a fire hazard for $30-40..

I may just do the 10/2 indoor/outdoor TC wire from NAWS.. 65 feet (what I need) works to $72.19 shipped..

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

I found a decent deal on some wire listed as:

10 AWG
600 V
Type XLP, RHW-2 or USE-2

Sounds like it will fit the bill..

Opinions??

Vic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Al,

Do you have a link to the spec sheet?

Is the manufacturer speced?

Vic

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Its Kris-Tech wire up in NY..

Seems spec'd well per there website. its USE-2 wire 90C etc.... not full UL4703 PV wire with the double insulation..

The pricing of $25/100 feet seems pretty good.. the other EB people want $40/100 for the same..

Still debating between that and the NAWS 10/2 tray cable which is rated 90'C and buriable, etc...

Photowhit · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

MC4 connectors are made to connect only the super insulated wires, they have gaskets that surround this thickly insulated wire, and would not seal around thinner wire.

Before I cut off the mc4 connectors and butt crimp the wire to some different wire and shrink wrap the connection, even with marine shrink. I would rather you used the standard MC4 connectors and the wire and build a simple enclosure for your combiner box. it can be just a big over sized box build in the shade of your solar panels. Then run a single line into the cabin.

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Photowhit wrote: »

MC4 connectors are made to connect only the super insulated wires, they have gaskets that surround this thickly insulated wire, and would not seal around thinner wire.

Before I cut off the mc4 connectors and butt crimp the wire to some different wire and shrink wrap the connection, even with marine shrink. I would rather you used the standard MC4 connectors and the wire and build a simple enclosure for your combiner box. it can be just a big over sized box build in the shade of your solar panels. Then run a single line into the cabin.

This is listed as my B plan actually..

I figured 4 AWG for a 10' run from the box to the combiner.. cost of $29 shipped..

Then shorter real PV UL4703 wire to the panels (which will be closer to the coombiner)..

Can you bury regular 4 AWG wire??

Vic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Al,

NO "regular wire", to me means THHN-THWN ... Building Wire. It is not rated for exposure (to the elements), let alone direct burial. PVC Conduit IS inexpensive, and can be buried, and exposed to the sun if it says, "Sun light resistant", or similar. You can put THHN inside PVC conduit (or Rigid/IMC) and bury that ... just glue the PVC joints well.

USE-2 wire is rated for exposure and direct burial, you should check to make certain that USE-2 says "sunlight resistant". Believe that ALL real USE-2 should be sunlight resistant, but try to make certain, if you do use it.

Most Combiner boxes are rated for exposure. There are some that are indoor only -- like the MN Baby, and Big Baby boxes, which can be used as combiners, but technically, are not exactly combiners (to me, at least).

All of these items that you are considering have numerous trade-offs, as you know. It is refreshing that you are thinking about all of these issues and asking questions BEFORE buying a lot of incompatible stuff. Some folks are tempted by the low price of something, without knowing or asking about how the cheapo item will function.

Good Luck, Vic

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Vic wrote: »

Al,

NO "regular wire", to me means THHN-THWN ... Building Wire. It is not rated for exposure (to the elements), let alone direct burial. PVC Conduit IS inexpensive, and can be buried, and exposed to the sun if it says, "Sun light resistant", or similar. You can put THHN inside PVC conduit (or Rigid/IMC) and bury that ... just glue the PVC joints well.

USE-2 wire is rated for exposure and direct burial, you should check to make certain that USE-2 says "sunlight resistant". Believe that ALL real USE-2 should be sunlight resistant, but try to make certain, if you do use it.

Most Combiner boxes are rated for exposure. There are some that are indoor only -- like the MN Baby, and Big Baby boxes, which can be used as combiners, but technically, are not exactly combiners (to me, at least).

All of these items that you are considering have numerous trade-offs, as you know. It is refreshing that you are thinking about all of these issues and asking questions BEFORE buying a lot of incompatible stuff. Some folks are tempted by the low price of something, without knowing or asking about how the cheapo item will function.

Good Luck, Vic

Thanks.. I am trying to go slow and not too cheap..

This is a piece-meal system that won't be installed till either December or Spring.. (pending on my pocket to get back to TX)..

I have an indoor 'combiner box'.. so mounting outside means building a box to hold it.. then buying the 4AWG and conduit holder (as you suggested) or paying more and getting some 4 AWG USE-2 rated wire.. which is $42.78 for 20' shipped.. (which isn't too bad).. then spend another $40-45 on the shorter run of say 50' of PV wire.. (works to a $90 expense)..

But after all that.. I still would need to make a BOX for the combiner box..

I'm sticking with regular 10AWG PV UL4703 wire.. I have a sample that should be here tommorrow for me to check before I pay.. and I've come up with 200' for less then $95..

NOTE: I found some EB people are selling USE-2 wire as full-blown PV wire.. as they confuse the wording to get you to buy.. :grr

ywhic · June 2012

Re: Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Well I got some 10 AWG UL4703 Wire.. Its got an OD of 6mm (like regular PV wire).. and has 37 strands of Tin Annealed Copper.

It was a decent deal on it.. I also have about 50 extra feet if anyone wants to PM me we can make a deal on it.

Its marked as such on the wire:

10 AWG

XLPE

600V 90'C Wet/Dry Rated

Sunlight Resistant

VW-1 or RHW-2

ROHS

Using LandScape 10/2 or 12/2 wire for going to panels from combiner..??

Comments

Categories