Proper torque for aluminum conductors

[BlownSilverado]

Hey guys I'm getting the 2-2-4-6 mobile home feeder wired up to my shop, I have a 6x6 junction box attached to the house that I'm using to splice the copper conductors from my main panel to the aluminum MHF feeding the shop.

I'm using a greaves insulated connector USAD2-2 for the connections, the installation instructions for the connector says to torque to 130 inch-pounds, however I tried this on a test piece of #2 aluminum using my new torque wrench set to 130 inch-points and the lug went straight through the wire before it reached 130 inch-pounds. What do you guys torque #2 aluminum conductors to?

Greaves connector installation instructions.

On another note, my siemens panel said to torque the A and B lugs to 110 inch-pounds, however on the main breaker in the panel it said 55, so I used 55 which seemed plenty tight. I don't see how aluminum can be torqued to 100+ inch-pounds. What's the deal?


Any comments on my panel installation and wiring so far? Thanks guys.

 

[Beemer533]

Are you positive you didn't have your torque wrench set to FT/LB instead of IN/LB? At 130 IN/Lb (10 FT/LB)it does not seem likely that you could go through the wire...

I think you are just mixing up IN/LB with FT/Lb...

 

[zmaxmotorsports]

Id switch over to emt just above the floor inside the garage to the panel ,you also need a bushing on the fitting inside the box.
Can you post a picture of the splice/couplings that youre using?That number is just over 10 ft lbs according to my math,Id just snug them up really good with a 3/8 drive or an allen wrench.

 

[BlownSilverado]

Yes I'm sure I had it set to inch-pounds. Even at 80 inch-pounds the lug starts to mash into the conductor.

I'm using the #2 connector for the two hots, and the #4 connector for the neutral and ground.

 

[Beemer533]

Are you going to have enough room in that 6x6 box for those? That seems tight..

 

[zmaxmotorsports]

Is there a fitting where the wire goes out the back side of the j box?

 

[Charles (in GA)]

Did you do load calcs? You need to do that if reduced neutral is used. Normally you would use 2-2-2-4 MHF with a full size neutral.

6x6 box seems rather small.

I see screws inside the 6x6 box. Not supposed to do that unless box is approved for them and box protects heads of those screws from damaging the wiring.

 

[toplessHO]

dont think PVC is legal inside
Stub up height only and convert to metallic.
best way to terminate aluminum is a hypress lug or micadapt

 

[BlownSilverado]

Is there a fitting where the wire goes out the back side of the j box?

Will have to check on that. Electrician mounted the box and ran the wire from the main panel to the jbox. The wire does have a thick insulation encasing the group of wires along with the individual conductor insulation.

Did you do load calcs? You need to do that if reduced neutral is used. Normally you would use 2-2-2-4 MHF with a full size neutral.

6x6 box seems rather small.

I see screws inside the 6x6 box. Not supposed to do that unless box is approved for them and box protects heads of those screws from damaging the wiring.

Not sure why the electrician added 4 screws inside of the box, I can take those out no problem.

Here are my load calcs, look like they check out OK? Keep in mind all of these will not be on at the same time.

dont think PVC is legal inside
Stub up height only and convert to metallic.
best way to terminate aluminum is a hypress lug or micadapt

Why would PVC be illegal inside of a structure? I've called my parish permit office twice and asked if I need a permit and I want to get my work inspected however they stated since it is not a new meter installation they do not require a permit and do not inspect work after the meter is installed. Crazy right?!

 

[Charles (in GA)]

dont think PVC is legal inside
Stub up height only and convert to metallic.

misinformation...... nothing in the code to prevent its use inside.

 

[rockwithjason]

something is seriously wrong if you are going thru the wire. use a different torque wrench and try again. 10 ft/lb is not that much torque

 

[zmaxmotorsports]

misinformation...... nothing in the code to prevent its use inside.

How about physical protection?

 

[PaulyC]

As long as it's sch 80 it's good

 

[AlwaysFixingSomething]

Why are you using those insulated terminal blocks anyway?

All you need is these
http://www.homedepot.com/p/Blackburn-1-1-2-in-x-39-64-in-Type-ASR-Splicer-Reducer-with-Solid-Barrier-Wire-Stop-2-Pack-ASR1114-B2-10/100126602

A lot cheaper and will work just fine. Some rubber tape then some Super 33 vinyl tape and you are good to go.

 

[351cmach]

Why are you using those insulated terminal blocks anyway?

All you need is these
http://www.homedepot.com/p/Blackburn-1-1-2-in-x-39-64-in-Type-ASR-Splicer-Reducer-with-Solid-Barrier-Wire-Stop-2-Pack-ASR1114-B2-10/100126602

A lot cheaper and will work just fine. Some rubber tape then some Super 33 vinyl tape and you are good to go.

cleaner and neater looking than a ball of bubble gum

 

[zmaxmotorsports]

As long as it's sch 80 it's good

Would you rather bump a piece of sch 80 or a piece of emt if you bump it with a car?Ill go with the emt myself.
I would've just brought the pvc right into back of the box from the outside to avoid the issue on that side of a garage.

 

[zmaxmotorsports]

cleaner and neater looking than a ball of bubble gum

Hey I like split bolts and bubble gum !

 

[AlwaysFixingSomething]

cleaner and neater looking than a ball of bubble gum

Who gives a **** what it looks like inside a jbox? As long as the connection is safe and secure that's all that matters. I make the inside of my panels neat but inside a jbox like this situation who cares.

You gonna break an iron and smooth out the wrinkles on the wire too?

 

[351cmach]

Who gives a **** what it looks like inside a jbox? As long as the connection is safe and secure that's all that matters. I make the inside of my panels neat but inside a jbox like this situation who cares.

You gonna break an iron and smooth out the wrinkles on the wire too?

I like all my work to be neat weather it can be seen or not. That's the difference between hacks and people that care about their work.

 

[AlwaysFixingSomething]

I like all my work to be neat weather it can be seen or not. That's the difference between hacks and people that care about their work.

So a splice tap or a split bolt is hack work now...kid you are hilarious I see why all those electricians never came back to your job because you were probably running your mouth telling them your "experience and know how"

 

[351cmach]

Who gives a **** what it looks like inside a jbox?

Not giving a **** what their work looks like because it's covered up. I would hate to see what your work looks like behind plastered wall.

 

[AlwaysFixingSomething]

Yeah who gives a **** what the inside of the jbox the op has pictured. You make secure connections and close the box up.

Tell me exactly how would you make a junction box pretty inside...tell us...I'm waiting for this gem

 

[dw1]

Penetrox or Noalox compound on the wires before connecting, tightten down, try to wiggle.move wire around, tighten again, all will be well. You can always come back in 6 months and check connections again to be safe.

 

[zmaxmotorsports]

Not giving a **** what their work looks like because it's covered up. I would hate to see what your work looks like behind plastered wall.

I don't know about anybody else but this is generally what my work looks like behind the sheetrock,and I love split bolts in junction boxes and on service drop connections.

 

[AlwaysFixingSomething]

I don't know about anybody else but this is generally what my work looks like behind the sheetrock,and I love split bolts in junction boxes and on service drop connections.

Looks good but can't tell by the picture if you have bundling issues. Electricians don't waste time with zip ties unless it's control wiring PLC stuff. Yes if it was my own home and i had unlimited time to do it sure. My customers don't want to pay me to beautify wires that will be covered up never to be seen again. The zip ties don't make the installation any better or the electricity flow better The joists are spaced 16 on center plenty of support for the wires no need for zippies.

 

[zmaxmotorsports]

Looks good but can't tell by the picture if you have bundling issues. Electricians don't waste time with zip ties unless it's control wiring PLC stuff. Yes if it was my own home and i had unlimited time to do it sure. My customers don't want to pay me to beautify wires that will be covered up never to be seen again. The zip ties don't make the installation any better or the electricity flow better The joists are spaced 16 on center plenty of support for the wires no need for zippies.

Yeah Ive had a couple guys complain about bundling over the years,but Ive never had an inspector ***** about it.Those are all runs for 3way switches.
The zip ties just keep everything flat/straight/organized is all,Ive done it that way for over 40 years.

 

[AlwaysFixingSomething]

Yeah Ive had a couple guys complain about bundling over the years,but Ive never had an inspector ***** about it.Those are all runs for 3way switches.
The zip ties just keep everything flat/straight/organized is all,Ive done it that way for over 40 years.

Hey if they pay you to do that then who can argue with it. Maybe you can work with this guy

 

[Charles (in GA)]

http://static.rcgroups.net/forums/attachments/1/1/7/4/6/a698125-228-*******%20contest.gif?d=1137072322

enough already................

 

[BlownSilverado]

Anyway back the f on topic... I went out and retested with my torque wrench and got better results tonight. I'll upload some pics of the wire at 100 and 130 inch pounds. The lug mashed into the two top strands but didn't break through. The remaining strands were undamaged so it looks good to me. Have you guys ever heard of a county (parish) that didn't require permit or want to inspect electrical work past the meter box?

 

[zmaxmotorsports]

About 15 years ago I was doing a really big job in carter lake ia,When the city inspector showed up (a guy named preston)I hah to explain to him what a gfci was!
Sometimes its just better to keep the inspectors out of the picture!

 

[Charles (in GA)]

Have you guys ever heard of a county (parish) that didn't require permit or want to inspect electrical work past the meter box?

Many rural areas of the US are only interested in basic inspections, there are probably some places where there is no inspection at all. Many counties want permit processes to pay their own way, and depending on the amount of construction going on, the one and only inspector may be too busy, or the one and only department manager/clerk/inspector/janitor may be too busy to deal with it. They basically have to chase the money and that would be new homes and commercial construction. To inspect everything would require more help, but not bring in enough more money to make it worthwhile.

Charles

 

[AlwaysFixingSomething]

Anyway back the f on topic... I went out and retested with my torque wrench and got better results tonight. I'll upload some pics of the wire at 100 and 130 inch pounds. The lug mashed into the two top strands but didn't break through. The remaining strands were undamaged so it looks good to me. Have you guys ever heard of a county (parish) that didn't require permit or want to inspect electrical work past the meter box?

Just tighten the f ing things down by feel scrap the torque wrench bs. That's what i do but i do this for a living, i know by feel how tight a lug needs to be tightened. Your not in an industrial setting where torquing lugs is critical and must absolutely be torqued to spec.

 

[Norcal]

The NEC REQUIRES torqueing all connections. In quite a few areas (but not in California) the only electrical inspection is by the PoCo, and all they look at is the service, in one place they ran triplex inside a house w/ steel studs. ( 2 insulated conductors wrapped around a bare AL conductor used for overhead service drops, not even a recognized material in the NEC). The only inspection there is septic.

 

[rockwithjason]

he must have drank a bunch of water because i see he is ready to start ******* again.

 

[351cmach]

can we give this back to the OP

 

[alfredeneuman]

Just tighten the f ing things down by feel scrap the torque wrench bs. That's what i do but i do this for a living, i know by feel how tight a lug needs to be tightened.

I used to do some Quality Control as a part of my job as a Project Super for an EC.
Part of my job was to check for correct torquing of the lugs.
Virtually all of the lugs that the guys did by "feel" tested either under or overtorqued. They, too, did this for a living.

In my area you need to submit a "Torque Letter" prior to inspection that states that you've torqued all the lugs to specs.
Quite a few jurisdictions have the electrician do the torque checks right in front of the inspector.

 

[APEowner]

To the OP: I'm really suspicious of your new torque wrench. Did it come with a certificate of calibration? How much experience do you have with torque wrenches? Is it possible that you're not using it correctly?

 

[AlwaysFixingSomething]

I used to do some Quality Control as a part of my job as a Project Super for an EC.
Part of my job was to check for correct torquing of the lugs.
Virtually all of the lugs that the guys did by "feel" tested either under or overtorqued. They, too, did this for a living.

In my area you need to submit a "Torque Letter" prior to inspection that states that you've torqued all the lugs to specs.
Quite a few jurisdictions have the electrician do the torque checks right in front of the inspector.

I have installed hundreds of residential panels and never used a torque wrench. Same with most electricians. Again it's not critical in a residential application. Commercial and Industrial yes but residential no.

The panel the OP has probably won't ever have anything more then a 40 amp load on it if that. Also the aluminum wire today doesn't have thermal expanison or creep issues like the older aluminum from the 60s had.

If your inspector requires you to torque them in front of him then do it. It's not done that way in PA and NJ in residential.

 

[BlownSilverado]

Not sure what was up the other night...just trying to do it by the book guys. Didn't intend to get everyone's ******* in a knot. Just wanted to know if there were torque differences between copper and aluminum.

All I have left to do on the feed is connect the wires in the jbox, then connect the shop supply breaker in the main panel and install lugs/wires on the neutral/ground bus bars in the main panel. After that it's onto wiring up the shop for lights and outlets

 

[alfredeneuman]

Just tighten the f ing things down by feel scrap the torque wrench bs. That's what i do but i do this for a living, i know by feel how tight a lug needs to be tightened. Your not in an industrial setting where torquing lugs is critical and must absolutely be torqued to spec.

If as you say, you've never used a torque wrench, how could you possibly be able to tell by feel how tight a lug should be tightened?