looking for some help/guidance IRT wiring, THHN vs UF-B vs THWN vs etc. etc. etc.

[Daddy Tanuki]

@All thanks for the input, going to bed got an early morning tomorrow and its past this grumpy old mans bedtime.

 

[GuyG]

The current-carrying capacity depends on more than just the copper cross section. Insulation makes a difference. The copper cross section should be constant between Japan and US, but the insulation might not be.

 

[DIYrich]

first let me clarify I just need short 4-6" pieces to use as an example for the local supply companies so I need whatever size would be used for a constant 40 amps. (would never be constant and would probably upsize to something that could handle 50 or 60 amps just to be safe.)

12 awg is 20 amp circuits
10 awg is 30 amp circuits
8 awg is 40 amp circuits
6 awg is 55 amp circuits
4 awg is 70 amp circuits

That is the max rating for the circuit. Constant load is 80% of that so 6awg for 55 amp circuit that can do 40 amps continuous. Typical rating for the insulation is up to 600v.

i was looking at this size as it says it is good to 55 amps at 60°c

https://www.wireandcableyourway.com/6-awg-thhn-building-wire

The wiring in question is between the main power panel in the shop where the inverters and the batteries are all located to the sub panel at the house. and between the sub power panel in the house to the the water heater. so its about a 30-35 meter run including ups downs etc, with no major bends until it goes under the house and comes up through the wall. then another 10 meter run to the water heater.

Japan voltage is 100v, although some areas might be 200v.

Using 6awg wire, 35 meters 100v voltage drop at 40 amps is 4.06%. If you increase to 4awg, then the voltage drop is 2.64%. At 200v, 2.03% and 1.32%, respectively.

 

[Hedges]

it will be run underground in a 4" pipe i installed 8 years ago, then come up under the house and if need run in conduit from there.

If run in conduit, not direct burial, then don't need UF.
You do need wire for wet location. THHN itself is not but THHN/THWN is. Sometimes advertised as "THHN" but also has THWN printed on the insulation.

XHHW also for wet, wider temperature range.

THHN vs. XHHW: What Is the Difference? | Multicom

When designing and building a new facility or machine, engineers need to fully understand the specifications – the strengths and weaknesses of each wire available for the job. The biggest challenge for an engineer is to balance the best wire for …

www.multicominc.com

You should have ampacity charts like this for your local materials:

https://usawire-cable.com/wp-content/uploads/nec-ampacities.pdf

https://media.distributordatasolutions.com/ThomasAndBetts/v2/part2/files/File_7437_emAlbumalbumsOcal20(USA)oc_1_g_nec31016pdfClickHerea.pdf

Also wire gauge to conductor diameter and cross section.
That should clear up all confusion except possibly alloy.

Wire gauge size chart | AWG table

American wire gauge size calculator and chart.

www.rapidtables.com

 

[Consumerbot3418]

i think the 6 AWG THHN is the way to go, unless for electrical reasons it is not. My mailing address is a USPS military postal address so shipping is not that bad. if the consensus is that 6 AWG THHN is good enough then I have two options. order it from the states via the link i posted, or find something that is comparable here and buy locally. not sure which is cheaper but until I can get a sample to show them, I am at a loggerhead

@All thanks for the input, going to bed got an early morning tomorrow and its past this grumpy old mans bedtime.

Came across this thread just a tiny bit too late -- I could have gotten a little piece of #6 THHN/THWN on its way to you today. PM me if the other guy doesn't come through.

 

[Daddy Tanuki]

To all the contributors, it looks like Sparky JO has several short pieces of sample of several different "common" wires used in the US for what we do. this will allow me to at least point to something and mumble semi intelligently to the local suppliers. anybody think I need to go with something thicker than the #6 THHN/THWN?

 

[timselectric]

anybody think I need to go with something thicker than the #6 THHN/THWN?

Nope

 

[SparkyJJO]

I got the samples together but local PO is not open. Will try to mail ASAP

 

[Daddy Tanuki]

I got the samples together but local PO is not open. Will try to mail ASAP

(joke) "Whoa Slow your Roll Sparky... you still have not told me what favors i need to trade for this boon " we talking first born son? he's about 38 now so not sure you want that one.. though he is self sufficient. seriously let me know what I owe you though.

 

[robbob2112]

You just want the mm^2 conversion for common awg?

 

[Daddy Tanuki]

You just want the mm^2 conversion for common awg?

View attachment 227881

they have some weird ass sizing called skei? not sure of the spelling. I went in and was like yeah I need a 6 gauge multi strand wire for a 40-50 amp circuit and they were like no such thing as 6 "skei" you need either 8 "skei" or larger. (they do not use AWG. On the smaller wire it is in MM but not MM squared. (I do not think, though it could be.) They have 1.25mm, 1.5, 1.75. 2.0, until about 12 gauge, then somewhere after the 12 gauge mark they go to this weird ass "skei" thing.

Their numbers the larger the number the larger the cable, and they were like a 4"skei" will not carry that much amperage. and the 8 "skei" is huge. So i honestly have no clue. I just want something to present to them so they can say OK this is the same as XX "skei" and then i can order from them, or if its cheaper with shipping, order from the US.

This is all very much a lost in the translation thing. even though I have lived here for 40 years, language wise this is a specialty niche, where they have their own words that even somebody who is a certified translator would have to look up the Kanji and then translate to engrish. There are time when simply having a sample is faster and easier then digging through the minutia.

 

[Hedges]

Should be able to translate everything into mm^2 of copper conductor. Then I would expect it to make sense.
The US/English scale of "gauge" is backwards, apparently related to have the wire is drawn.

Beyond that, temperature handling of insulation, temperature rating of terminals, and number of current-carrying conductors in cable or conduit.

Current handling is not strictly proportional to cross section because surface area to dissipate heat doesn't increase at same rate as cross sectional area.

Presumably you can read the funny characters:

AWG

edn.itmedia.co.jp

I'm not finding "skei"

 

[Brucey]

they have some weird ass sizing called skei? not sure of the spelling. I went in and was like yeah I need a 6 gauge multi strand wire for a 40-50 amp circuit and they were like no such thing as 6 "skei" you need either 8 "skei" or larger. (they do not use AWG. On the smaller wire it is in MM but not MM squared. (I do not think, though it could be.) They have 1.25mm, 1.5, 1.75. 2.0, until about 12 gauge, then somewhere after the 12 gauge mark they go to this weird ass "skei" thing.

Their numbers the larger the number the larger the cable, and they were like a 4"skei" will not carry that much amperage. and the 8 "skei" is huge. So i honestly have no clue. I just want something to present to them so they can say OK this is the same as XX "skei" and then i can order from them, or if its cheaper with shipping, order from the US.

This is all very much a lost in the translation thing. even though I have lived here for 40 years, language wise this is a specialty niche, where they have their own words that even somebody who is a certified translator would have to look up the Kanji and then translate to engrish. There are time when simply having a sample is faster and easier then digging through the minutia.

Went down a rabbit hole, some Norse god thing and it can mean "to cut" which I guess makes sense.

Jeffrey Aronson: When I use a word . . . Science—the cutting edge - The BMJ

The IndoEuropean root from which the word “science” eventually descends is SEK, or in an extended form SKEI, meaning to cut. In Greek σχίζειν meant to split or rend, giving [...]More...

blogs.bmj.com

 

[Daddy Tanuki]

Went down a rabbit hole, some Norse god thing and it can mean "to cut" which I guess makes sense.

Jeffrey Aronson: When I use a word . . . Science—the cutting edge - The BMJ

The IndoEuropean root from which the word “science” eventually descends is SEK, or in an extended form SKEI, meaning to cut. In Greek σχίζειν meant to split or rend, giving [...]More...

blogs.bmj.com

i never even thought of looking at languages other than Japanese in regards to this, but it would not surprise me as they imported a lot of words in the time frame of about 1930 onward from other countries.... A/C is air con for instance short for air conditioning from the US. Bonnet the hood of a car from Great Britain Pee Shee (Peronal computer) etc.

 

[Daddy Tanuki]

Should be able to translate everything into mm^2 of copper conductor. Then I would expect it to make sense.
The US/English scale of "gauge" is backwards, apparently related to have the wire is drawn.

Beyond that, temperature handling of insulation, temperature rating of terminals, and number of current-carrying conductors in cable or conduit.

Current handling is not strictly proportional to cross section because surface area to dissipate heat doesn't increase at same rate as cross sectional area.

Presumably you can read the funny characters:

AWG

edn.itmedia.co.jp

I'm not finding "skei"

thats their version of a white paper that would be used to translate back and forth into the consumers they are aiming at. IE designed to let them talk to us or a place that uses the mm crosssecton. and while they might use the mm cross section in the factory that makes the wire, or in a engineering blueprint, they do not use it normally at the local supplier. hence possibly part of the confusion.

 

[SparkyJJO]

Hoping to make it to the post office today FYI

 

[Daddy Tanuki]

Hoping to make it to the post office today FYI

No worries you are helping me. I would be a pretty piss poor human being to complain about a person who is helping me.

 

[Brucey]

They prob had to bring the postmaster out of retirement, sir sorry to bother you but we actually had someone walk into our post office and he wants to mail a package!

 

[SparkyJJO]

They prob had to bring the postmaster out of retirement, sir sorry to bother you but we actually had someone walk into our post office and he wants to mail a package!

In my little podunk town of 900 people I still have to write a paper check for my water bill and put it in the drop box!

 

[Brucey]

In my little podunk town of 900 people I still have to write a paper check for my water bill and put it in the drop box!

We used to have a local mail slot at the local post office. Would get there super quick. Obviously that was found to be way too efficient and so everything has to be shipped to the city 30 mins away where the valuables can be stolen and then maybe 3-5 days later it may or may not be delivered.

 

[Hedges]

We used to have a local mail slot at the local post office. Would get there super quick. Obviously that was found to be way too efficient and so everything has to be shipped to the city 30 mins away where the valuables can be stolen and then maybe 3-5 days later it may or may not be delivered.

My local post office in Oakland (Laurel district, down on the flat lands) used to have a mail drop box. They're looking for who stole it.

 

[Daddy Tanuki]

In my little podunk town of 900 people I still have to write a paper check for my water bill and put it in the drop box!

That’s not a bad thing! I came from a gravel road that was 4 miles from Merom (pop 300) and 3 miles from Graysville (pop 150) it’s not a bad way to live!

 

[Daddy Tanuki]

My local post office in Oakland (Laurel district, down on the flat lands) used to have a mail drop box. They're looking for who stole it.

Reinstall one and mark it as election ballot dump location…. It will get checked daily and nobody will mess with it.

 

[Brucey]

Reinstall one and mark it as election ballot dump location…. It will get checked daily and nobody will mess with it.

Scroll to 40 seconds in...

 

[ThaiTaffy]

they have some weird ass sizing called skei? not sure of the spelling. I went in and was like yeah I need a 6 gauge multi strand wire for a 40-50 amp circuit and they were like no such thing as 6 "skei" you need either 8 "skei" or larger. (they do not use AWG. On the smaller wire it is in MM but not MM squared. (I do not think, though it could be.) They have 1.25mm, 1.5, 1.75. 2.0, until about 12 gauge, then somewhere after the 12 gauge mark they go to this weird ass "skei" thing.

Their numbers the larger the number the larger the cable, and they were like a 4"skei" will not carry that much amperage. and the 8 "skei" is huge. So i honestly have no clue. I just want something to present to them so they can say OK this is the same as XX "skei" and then i can order from them, or if its cheaper with shipping, order from the US.

This is all very much a lost in the translation thing. even though I have lived here for 40 years, language wise this is a specialty niche, where they have their own words that even somebody who is a certified translator would have to look up the Kanji and then translate to engrish. There are time when simply having a sample is faster and easier then digging through the minutia.

Thailand is the same they seem to have their own measurement system especially with things like land. Best conversation I've had on conversion was about horse power with a local guy who was curious how it converted to buffalo or elephants, world would be in interesting place if we measured things in elephant power.