what type of wires to use?

[kauaisolarman]

So i just finished wiring up my new system together.  it consist of 2 midnite CC 150SL & 200classic.  ran through a wire gutter for clean look.

after all day of wiring i got it done.  sadly as i was browsing the forums i realized i may have use the wrong wires   

i am using welding cable for all my wiring but it is not UL approved.  just realized this.  this is mainly the type of wire i used for my setup  ranging from 10-2 awg.
https://www.amazon.com/gp/product/B01JMNMM8S/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

or

https://www.amazon.com/gp/product/B0167K7GO4/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

are these wires sufficient or do i need to re do everything and switch to UL approved wires?

i also purchased a set of these which have (UL) rated on them but do not have the NEC wire type designation listed on them.  would these still be NEC compliant or do the NEED to have the (UL) and a NEC wire type designation (thwn,thhn,thw,etc.)?

https://www.amazon.com/gp/product/B00TANRTSO/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1


this article says it needs to have both to be NEC compliant can someone verify?  thanks
http://www.homepower.com/articles/solar-electricity/design-installation/inverter-battery-cables


just want it to be safe. i know NEC guidelines promote safety but is it not safe to use the wires i used above?  i used ferrules/cable lugs for all connections with these wires.

thanks again for any input

[ClassicCrazy]

The insulation is different on the approved type wiring. It is rated for different temperatures as well as being very rugged. I think the heating standards especially apply when you put multiple conductors in conduit and run rated amperage's through them. You should do some research and maybe check with an electrician.

I don't have any direct experience with using those welding cables. Big question is do you need it to meet some kind of code inspection ? Probably not or you would have not been asking this question. If you don't have code it all depends on which level of risk you wish to take with your system and safety.

I think I have heard  there can be issues with trying to properly compress all those fine wires in compression terminal blocks.

I know a lot of people have used welding cable for the short runs from inverter to batteries because it costs less for 4/0 welding cable wire.  When I did my system I spent the extra money and got marine grade wire for my inverter partially because I found a place that would make them up with the length and lugs that I specified. They are super rugged and they really know how to crimp terminals on and used the special heat shrink that makes it water tight. Cost was higher than welding cable but I think it was a good investment in the long run because those are not going to ever have any problems. I would have to go look at them to see what marine wire standards they have.

Larry

[ClassicCrazy]

I just looked up EWCS Branded  - that is a company trademark and name . It is not any electrical standard.

http://ewcswire.com/blog/

Northern Arizona Wind Sun has a good forum and the question you asked has probably already been asked and answered there

http://forum.solar-electric.com/

[Vic]

Hi kauaisolarman,

You  did say,   "   ...   after all day of wiring i got it done.  sadly as i was browsing the forums i realized i may have use the wrong wires   

i am using welding cable for all my wiring but it is not UL approved.  just realized this.  this is mainly the type of wire i used for my setup  ranging from 10-2 awg.
https://www.amazon.com/gp/product/B01JMNMM8S/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

   ...   "

It IS true that screw-type terminals are not designed to accept fine-stranded cable,  and the welding cable that I have seen IS fine strand.

Cables,  crimped with the correct lugs  --  made specifically for fine strand cable should be OK, when correctly crimped.    Crimped lugs will not be a solution for smaller breakers,  busbars,  etc,  with screw connections.  And,  there can still be issues,  if the system will be Inspected for Code compliance (as CC Larry mentioned).

There are provisions in the NEC for cables,   like the VW-1 fire provisions that welding cable may not meet,  etc.  This applies for cables that are inside inhabited structures,  IIRC.

Building wire  with THHN  ratings are easy to use in smaller diameters,  and  this is the type of cable that screw terminals on breakers,  busbars,  etc are designed to accommodate,  and  this building wire is inexpensive.

At the big box retailers,  the reference cable that I use for monitoring the relative price change of building wire (500' #10 THHN stranded) is now about 60% of the price that it was about two years ago  ...   seemingly inexpensive.

It is very important,  IMO,   that the lugs used on fine strand cable,  be intended and designed for that use.    One does not loose connections on any cable,  especially those carrying large currents.

FWIW,   Good luck with the new system.     Vic

[kauaisolarman]

thanks for the replies.

I did use lugs or ferrules on all wires that were going into screw terminals/bus bars and also used ferrules on all the circuit breakers so that the stranded wire stays together.

used marine grade anchors
https://www.amazon.com/gp/product/B000NHZYRY/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

made really good connections for all wires going to a terminal or bus bar with the ferrules.  no lose connections.  all lugs were installed with hammer type crimper and waterproof heat shrink with adhesive lining was used to seal it together.

I read through some earlier posts on the forum and seen people try to tin these stranded wires but the consensus seems to be no solder or tinning, so I purchased a bunch of ferrules and ferrule crimper and went to work.

i am never sending full current rating through any wires.  for example my 2 awg will see 80A max.

Just more worried about the heat resistance and durability of the wire jacket.  don't have to pass any inspections but i tend to be very anal and want to be able to get a good night sleep not worrying about evacuating my house because of you know what

I also purchased a few of these wires that say they are UL rated but they have no NEC ratings on them.  any input on using these wires or should i just purchase all new and look for UL and NEC ratings printed on the jacket.
https://www.amazon.com/gp/product/B00TANRJNO/ref=oh_aui_detailpage_o00_s01?ie=UTF8&psc=1

thanks again people  very helpful

[kauaisolarman]

does marine wire have the same NEC ratings as non marine?

was looking at the Vertex wire website and it says all their wire is UL Standard 1426 BC-5W2 (Electric Cable for Boat) compliant.  didn't see anywhere specifying NEC ratings anywhere.

is it OK to use marine cable that has the UL listing but does not have any NEC ratings?

http://www.vertex-marine.com/ul-1426-boat-cable-bc-5w2/battery-cable/8-awg-wire/

[Vic]

Hi Kauai..,

1.  Will your system be Inspected by some Building Inspector?

2.  On the Vertex site,  it looks like most of their Boat cable products are Fine-Stranded,   as was your Link to #8 AWG cable.   If you are using ANY fine-stranded cable on screw type terminals on breakers and busbars,  and any other connection that uses a screw to compress a cable or a "shoe" that presses on the cable,   IMO,  this would NOT be OK.   It is possible to use a crimped ferrule on fine strand cables to help reduce the risk of cold flow,  although this might not pass muster of careful inspection.   Personally would not use fine strand cable that is a smaller gauge (smaller diameter) than about #1 AWG,  and then only with proper lugs and crimping.  Would not use ferrules,  either,  as this is one additional point of some resistance in the circuit.

3.  Fine strand cables that have a properly crimped lug,  designed for use on fine strand cable,  and  attaches to a terminal,  using a bolt,  or nut would probably not be considered dangerous.

4. I am not a Code expert,   so the suitability of Boat cable for your system,  verses building wire  (THHN ...),  is something that I cannot comment on,  but,  if your system will need an Inspection,  you should probably speak with the Building Department officials that have specified just what they require in the way of cables,  and also ask what Code Revision that will need to be met.

To me,  the largest issue for any system would be that cables are sized correctly for the Overcurrent Protective Devices (circuit breaker or fuse) that are protecting those cables.   And,  that no fine strand cable is connected to a circuit using a compression type screw terminal.   Also,  meeting Ampacity Derating for ambient temperature,  and number of current-carrying conductors in conduit,  raceway,  etc,  as well as not filling any conduit with an excessive number of conductors.

...   and so on.   Some of the above are probably nits;
If the system will be inspected,  then follow the standards noted by the Authority responsible for the inspection.

Eliminate any fine strand cable terminated by a compression type screw terminal.

Realize that you are in HI,  and sourcing some of the specific parts for a compliant solar installation,  may not be at your finger tips.

Then relax and enjoy the fruits of all of your labor,  after any required inspection.

Just my opinions,   and,  getting a self-installed system on line,  is a real accomplishment,  so congratulations are in order,  even if a few things might need a bit of tweaking.   Vic

[ClassicCrazy]

I don't know what a hammer crimper is like but Harbor Frieght tools has an inexpensive hydraulic crimper that works great. You can also find the same type on ebay for low prices.
http://www.harborfreight.com/catalogsearch/result?q=hydraulic+crimper

I have one and it will squash crimps very tight so no air is in them or going to get in there .  It is a good tool to have for all size wires. I did use it to crimp some lugs that were bigger than the biggest die that came with it - but I was able to drill out one of the smaller ones . I usually use one die , then use  to the next smaller die to ensure it is squashed good.

Larry

[kauaisolarman]

thanks everyone for the input.

my system will not need to be inspected as it is a home off grid setup.  just trying to be as safe as possible.

guess i am going to switch everything out to UL rated wires with the NEC building wire ratings on them. I have 1 source of marine stranded wire that has both the UL rating and (THW) NEC spec printed on the jacket.  will double check with a local inspector to see if that would be up to standard with the use of the ferrules and if I get the green light i'm going the stranded ferrule route (just because i think its easier to work with)

anyway heres some pics of the progress so far, just sad that i have to start over.





all sealed up



I would think that the marine UL stuff would be better thank the regular building stuff as it sees a much harsher environment and conditions with the salt air and all.

I figured being out here in the middle of the ocean using all marine grade stuff would be better/safer than using regular building stuff.

none of the wires that i am using will see anything even close to their ampacity ratings and the breakers are all well below the ampacity rating for the wires.  for example the 6awg will see 40A at max and also has a 40A breaker used with that wire.  only thing in my system that comes close to ampacity rating is the 4AWG that is comming out of CC 1 to the battery and even that will only see 80A max and also has a 80A breaker on it.  all my wires should be adequately protected from overcurrent but i'm not sure if that will protect me from a fire.

[ClassicCrazy]

 Looks nice. I don't know about those ferrules on the ends of the wires though. When you crank it up get it too full capacity and use a thermal imaging camera and look at all those connections and see if they get warm. Then you know you don't have good connections.

I don't get what is wired up to your shunt . One side should go to the battery and nothing else. 

Larry

[Vic]

Hi Kauai..,

YES,  that installation looks very neat,  indeed.

The busbar on the top of the Shunt should be fine.  It is a bit difficult to see clearly,  but guess that the cable from the other side of the Shunt  --  the bottom in the photo goes under the busbar on the top of the shunt (and does NOT connect to that bar),  and proceeds directly to the battery negative.   That end of the Shunt should only connect to that end of the Shunt,  and the battery negative,  and nowhere else.

Am not a fan of ferrules,  as mentioned before,  but,  if there is no noticeable heating when the charging is maxed out,  or the inverter loads are maxed out,  then things are probably OK.

An inexpensive IR non-contact gun-type thermometer should be able to measure the temperatures of busses,  ferrules,  etc.

Vic

[kauaisolarman]

thanks guys

as far as the shunt goes  it is wired to the part of the box that says "connect battery negative here".  i was planning to connect battery negative there and just run that small jumper from there to the battery side of the shunt.

i was unsure about if i connect the battery ground to the stud on the box it will be bonded through the box to the earth ground that is also connected to the box.

should i just remove the jumper, not use the battery negative connection on the box and just run the battery negative straight to the shunt?

that was going to be my next question.

if not using ferrules then what would i use? even the Thhn building wire is "B" stranded and i was under the impression that no stranded wire can go under the screw type cinnections that are on the busbars?  if using building thhn "A-B" stranded how would they terminate into the busbar?

thanks again for input

[Vic]

Hi kauaisolarman,

First,  all of the busbars,  circuit breakers,  etc,  that use a screw as the connection method are designed to use THHN stranded cable.

Most THHN cable is 19 strand cable.  Small diameter and large diameter THHN cables might have 31 strands.   These cables are NOT Fine Strand types.   So,  NO ferrules would be required,  or desirable.

Am not certain just what panel you are using,  so,  should not comment of just where the connection to your ground rod/system should be made.

Regarding the Shunt,   Is there a piece of cable that is across the Shunt,  thus shorting it ?? ?

If there is this short across the Shunt,  it is not necessary,  as with a huge current flowing through it --  500 Amps  --  it drops only 50 millivolts,  which if  0.05 volts.  At 50 Amps of current the drop is 0.005 volts.

It is not clear in the photo if that cable from the lower bolt on the Shunt connects to the busbar mounted on the top of the Shunt.

FWIW.   Thanks for any clarification.   Vic

[kauaisolarman]

thanks vic.  the cable on the "battery" side of the shunt is NOT connected to the busbar on the other side of the shunt.  it is connected to the stud that comes attached to the BOX where i would also connect my battery negative cable directly to. 

basically battery negative going to stud on box and another wire going from the stud to the "battery negative" side of the shunt.

only battery negative is connected to the side of the shunt that WbJr is sticking out past.

thanks for the clear up with the building thhn.   may just switch everything to that thhn and not do any ferrules.

[ClassicCrazy]

If it was me I would run a cable - just one connector on the battery side of the shunt directly to the battery negative and not go to any buss bars. That makes just one solid connection and every other negative in the system would go to the other side of the shunt via bus bar or directly on that other side of the shunt bolt.

I wasn't sure from what you said - but the wiring from the battery side of the shunt has to be sized to take every load of the whole system including the inverter and associated surge ratings of the inverter.

Larry