# Best way to splice 6 gauge wire?



## JonCiccarone (Jan 10, 2016)

What is the best way to splice/connect 6awg THHN wire in a junction box?

TIA,
JC


----------



## surferdude2 (Nov 21, 2019)

I would use an Ideal 454 blue nut or a 342 Gray "Twister", either can handle #6 wire.


----------



## seharper (Mar 17, 2020)

The "MAC Block connector" is a miniature Polaris (or oversize Alumiconn, depending on how you want to think about it). It has 2 voids which max out at #6 wire, and is good for aluminum or copper. 

The MAC Block's best trick, though, is how it allows multiple smaller wires in one void (provided they are all the same metal). Thus it's a "Super Alumiconn" that can splice up to 4 aluminum wires to up to 4 copper wires. (or 8 coppers, or 8 aluminums).

Remember you need 5 cubic inches per wire at #6.


----------



## JonCiccarone (Jan 10, 2016)

surferdude2 said:


> I would use an Ideal 454 blue nut or a 342 Gray "Twister", either can handle #6 wire.


I believe those are both only rated for one 6awg wire, so only good to cap a 6awg wire, not splice two of them together.

JC


----------



## surferdude2 (Nov 21, 2019)

JonCiccarone said:


> I believe those are both only rated for one 6awg wire, so only good to cap a 6awg wire, not splice two of them.
> 
> JC


Not true, they are wire _connectors_.


----------



## jreagan (Feb 20, 2015)

The specs for the 454 Blue Wing-Nut says:


"Maximum wire capacity of one #6 wire and two #8 wires"


----------



## surferdude2 (Nov 21, 2019)

jreagan said:


> The specs for the 454 Blue Wing-Nut says:
> 
> 
> "Maximum wire capacity of one #6 wire and two #8 wires"


Which, for years, has led apprentices to believe that they aren't good for two #6's so you have to take time out to smack them on their forehead and explain how they need to use their common sense or else get an Ugly's Electrical Reference (cheaper than a NEC code book) and add up the in² properties of two #6 wires versus one #6 plus two #8.

Then make them buy beer for the crew on Friday after work for winning that contest that all good crews have.


----------



## Geochurchi (Nov 29, 2012)

Hi, these might be a better choice that the Blue wire nuts.
https://www.homedepot.com/p/Polaris-4-14-AWG-Bagged-Insulated-Tap-Connector-Black-IT-4B/303577920
Geo


----------



## carmusic (Oct 11, 2011)

i would use terminal block like that https://www.automationdirect.com/ad...,_ul_recognized,_175a-760a_(pb_series)/pb1012
if junction box is big enough


----------



## Oso954 (Jun 23, 2012)

> "Maximum wire capacity of one #6 wire and two #8 wires"


Here is the list of UL approved wire combinations for Ideal wire nuts.
https://images.homedepot-static.com/catalog/pdfImages/d1/d1776e2d-96c3-407e-a011-9f6f67f1241a.pdf

Go to page 5, the 454 is top of the page. 
First entry in the first column is 1 to 2 #6
Top of the second column, 2 #6 with 1 #14 or #12

You might want to bookmark the list or print a copy.


----------



## surferdude2 (Nov 21, 2019)

I'm sure Ideal would disagree with both of those expensive choices since they have been legally connecting a pair of #6's for years. You can even stick a #12 on that pair and still be within Ideal's own approved specifications.

Just so the thread is useful to those who don't have access to the properties of electrical wire, here's how it goes:

You can add up the conductor properties in either in² or circular mils to understand what Ideal is saying about the maximum capacity of their wire nuts.

E.G., Ideal lists the max. for the blue 454 nut at 1 #6 and 2 #8's.

A #6 conductor has a cross sectional area of .027 in² 
A #8 conductor has a cross sectional area of .017

Ergo, two #8 + one #6 = 2X.017+.027 = .061 in² (Maximum allowable use)
Hence, two #6 cond. = 2X.027 = .054 in² (allowed since well below the maximum)

So now @JonCiccarone You have some choices to pick from. Do what you think best.


----------



## jreagan (Feb 20, 2015)

My bad, I read that as an OR not an AND


----------



## rjniles (Feb 5, 2007)

A $15 Polaris or two $1 wire nuts. Hard decision, Not!

Sent from my moto g power using Tapatalk


----------



## surferdude2 (Nov 21, 2019)

jreagan said:


> My bad, I read that as an OR not an AND


Boy, that beer is gonna taste good come Friday! :vs_laugh:


----------



## JonCiccarone (Jan 10, 2016)

seharper said:


> The "MAC Block connector" is a miniature Polaris (or oversize Alumiconn, depending on how you want to think about it). It has 2 voids which max out at #6 wire, and is good for aluminum or copper.


These things look awesome, but seem a bit hard to find.


----------



## JonCiccarone (Jan 10, 2016)

surferdude2 said:


> Ergo, two #8 + one #6 = 2X.017+.027 = .061 in² (Maximum allowable use)
> Hence, two #6 cond. = 2X.027 = .054 in² (allowed since well below the maximum)


Thanks for clarifying that. I made the same mistake and read it as "*or* two 8's". I appreciate the help and will be buying a pack of blue 454's this week :thumbsup:

However, based off of Oso's attachment from Ideal, doesn't look like the gray 342's are UL listed for #6's. Looks like they max out at one #6 and one #8.

JC


----------



## surferdude2 (Nov 21, 2019)

JonCiccarone said:


> doesn't look like the gray 342's are UL listed for #6's. Looks like they max out at one #6 and one #8.
> 
> JC


Yes, close but no cigar! Thanks for pointing that out.


----------



## seharper (Mar 17, 2020)

JonCiccarone said:


> These things look awesome, but seem a bit hard to find.


They're even worse to search the web for. "mac block" won't even get you within 1000 miles. 

It's like when I was looking for the Monk episode where he has a level-checking level to check his level's level... and I search "monk level"... that did not go well  And I'm a Diablo player so I really should've known better!


----------



## circuitman (Aug 9, 2013)

copper split bolts also work good!:biggrin2::biggrin2::biggrin2:


----------



## Jim Port (Sep 21, 2007)

circuitman said:


> copper split bolts also work good!:biggrin2::biggrin2::biggrin2:


A lot of work to wrap properly, especially when wire nuts are available.


----------



## circuitman (Aug 9, 2013)

Jim Port said:


> A lot of work to wrap properly, especially when wire nuts are available.


but one thing is for sure they don't come loose easily.:biggrin2::biggrin2::biggrin2:


----------



## miamicuse (Nov 13, 2011)

a related question.


Someone suggested the Polaris connector, I have never used one, but how bulky are these connectors? Can you fit two of these inside a 4-11/16 box?''


If I use a Polaris connector to make the splice, two of them will be $33. 50 feet of 6AWG THHN at my local stores is about $36, last two times I had to make a splice for #6 wires after looking at the options I went back and replaced the entire run to eliminate the need for the splice altogether. Probably an overkill I tried the big wire nuts and for some reason they didn't seem as secure, it was hard to get them pre-twisted nice and tight. May be someone can explain how to pre-twist #6 stranded to #6 solid, solid to solid, or stranded to stranded then apply the wire nuts.


----------



## rjniles (Feb 5, 2007)

With large wire size I find it better not to pretwist.

Sent from my moto g power using Tapatalk


----------

