2-2-2-4 SER MHF vs Copper?

[gymbo39]

Good day GJ Comrades
I'm in the process of wiring my new shop (26x40 metal building) and am unsure of what wire I will be utilizing for the supply line from the main service panel (200 amp) to my sub panel (100 amp) in the shop. I originally intended to use -2 copper with a -4 or -6 ground but recently began considering using the 2-2-2-4 SER MHF aluminum wire I keep seeing so much on this site.
My question is this aluminum wire really a safe alternative to the copper wire? I understand its considerably less expensive but I am more concerned with durability and safety over cost.
If using the aluminum, is there anything special required at the points of connection at the main breakers? This wire, whether I use copper or the aluminum will be buried in 1.5 inch conduit.
Thanks for any help

 

[pattenp]

Todays' aluminum wire is very safe. Use antioxidant paste on the terminations and tighten the connections well. Also #2 AL maximum over current protection is 90 amps. You'd need to go to #1 AL for a full 100 amps, but MHF doesn't come in #1. The next size is 2/0. You could use individual #1 AL THHN/THWN or RHH/RHW

What's the distance of the run? I recommend 2 inch PVC conduit for the #2 AL.

 

[wyliesdiesels]

FYI MHF is not SER.

 

[gymbo39]

Thanks pattenp. The run is approximately 130 feet. I already have 1.5 inch conduit in the wall below the primary service at the house that installed while the wall was open so it would be pretty difficult to change that. Although I have not buried (or obtained) the 1.5" pvc for the run yet.

 

[gymbo39]

Whats your opinion on this wire?

http://www.homedepot.com/p/qv/205001908

 

[sublimate]

You can't use SER underground.

 

[pattenp]

That is SER and is only allowed above ground.

Whats your opinion on this wire?

http://www.homedepot.com/p/qv/205001908

 

[pattenp]

This is MHF, but in 2-2-4-6. It also come as 2-2-2-4.

http://www.homedepot.com/p/Southwire-2-2-4-6-Aluminum-MHF-Wire-By-the-Foot-30163099/205001794

Edit: Do you have a local Lowe's? They may carry 2-2-2-4 MHF in store. Don't get URD and MHF mixed up. URD is not allowed inside the structure because the insulation is not fire rated.

 

[theoldwizard1]

This is MHF, but in 2-2-4-6. It also come as 2-2-2-4.

If you are willing to limit the feed to the cable from your main panel to 70A (you can still have a 100A "main" breaker at the sub-panel), 2-2-2-4 MHF is good for 130'.

MHF can be direct buried, but must be in conduit above ground or in a building.

 

[pattenp]

Why 70 amps?

If you are willing to limit the feed to the cable from your main panel to 70A (you can still have a 100A "main" breaker at the sub-panel), 2-2-2-4 MHF is good for 130'.

MHF can be direct buried, but must be in conduit above ground or in a building.

 

[gymbo39]

Well I think I've decided to go with the -2 cooper with a -4 ground. Seems it will be reliable and safe

 

[My Old Tools]

2-2-2-4 MHF from Lowes and a 90 amp breaker and you are good to go.

 

[pattenp]

It's your money. I don't agree with the safety and reliability concern that you have with aluminum.

Well I think I've decided to go with the -2 cooper with a -4 ground. Seems it will be reliable and safe

 

[gymbo39]

Well from what I've read the aluminum is so much more difficult to work with around curves and such?

 

[wyliesdiesels]

Well from what I've read the aluminum is so much more difficult to work with around curves and such?

Where ever u read this its wrong. AL wire is softer than cu wire which is just the reason why my klein cable cutters are rated for 2/0 CU and 4/0 AL. AL is easier to work with than cu AND ALOT cheaper than CU!

The al wire of today is not the same dangerous al wire from the 60's and 70's!!

http://www.southwire.com/commercial/ALBuildingWire30YrsOfReliability.htm

 

[Falcon67]

I ran 2-2-2-4 mhf 120' for my shop. I used 2" conduit. Easy to pull with lube. I breakered at 70a because that was on the shelf at HD. I bought wire, 20 space box and head end breaker and spent under $250. Including pull soap and AL paste. I have a ton of powered tools and equipment and havent managed any trips.

 

[My Old Tools]

Definitely go up to 2" conduit if you have ANY 90's to pull.

 

[SALIV8]

I would never use aluminum wire. It's not worth the savings. Use copper and sleep well at night. Properly torque your lugs and you will never have a problem. There is a reason aluminum is not allowed in many cities.

Take shortcuts elsewhere... Imo.

 

[sublimate]

There is a reason aluminum is not allowed in many cities.

Got a link to that?

 

[Norcal]

I would never use aluminum wire. It's not worth the savings. Use copper and sleep well at night. Properly torque your lugs and you will never have a problem. There is a reason aluminum is not allowed in many cities.

Take shortcuts elsewhere... Imo.

It's fully NEC compliant to wire your house completely w/ aluminum there are no restrictions to doing so other then AL is not made in smaller sizes.


Aluminum installed correctly is safe & reliable, copper installed incorrectly is just as dangerous as aluminum installed incorrectly.

 

[hoylebros]

I wanted to post these pics for the OP and anyone else unsure of what the MHF wire looks like in the store. Your areas price may be different.

 

[outsider347]

Apologies for the hijack..

Can I use the
2-2-2-4 SER MHF for my application below?

House main power recently updated to 200A service

I,d like to have 60A minimum service to my back shop

Shop is 375 ft from the house

hope this is enough info

Thanks Gents
ed

 

[pattenp]

For 60A it's too far for #2 Al. You should go with 2/0-2/0-2/0-1 MHF. Don't use the term SER with MHF, SER is a different cable.

Apologies for the hijack..

Can I use the
2-2-2-4 SER MHF for my application below?

House main power recently updated to 200A service

I,d like to have 60A minimum service to my back shop

Shop is 375 ft from the house

hope this is enough info

Thanks Gents
ed

 

[wyliesdiesels]

For 60A it's too far for #2 Al. You should go with 2/0-2/0-2/0-1 MHF. Don't use the term SER with MHF, SER is a different cable.

The OP should rename the thread title because its misleading and incorrect as weve both pointed out!

 

[gymbo39]

finally got out the big tape measure and the distance from lug to lug will be approximately 150". To much for the 2-2-2-4?

 

[sublimate]

finally got out the big tape measure and the distance from lug to lug will be approximately 150". To much for the 2-2-2-4?

12.5 feet?

 

[Aceman]

finally got out the big tape measure and the distance from lug to lug will be approximately 150". To much for the 2-2-2-4?

What kind of equipment are you planning to have in the shop? HVAC?

 

[pattenp]

Remember, #2 MHF has a max over current rating of 90 amps. With a 150 feet of #2 MHF, to maintain a 3% or less voltage drop, you need to keep the total load at about 72 amps or less. But on the flip side, the feed should be sized at least to 125% of the figured loads. So #2 MHF shouldn't be used if your loads will exceed 80% of the 90 amp rating, or 72 amps.

 

[wyliesdiesels]

Remember, #2 MHF has a max over current rating of 90 amps. With a 150 feet of #2 MHF, to maintain a 3% or less voltage drop, you need to keep the total load at about 72 amps or less. But on the flip side, the feed should be sized at least to 125% of the figured loads. So #2 MHF shouldn't be used if your loads will exceed 80% of the 90 amp rating, or 72 amps.

An if he gets bigger wire to handle the load, hes gonna have a lot of fun pulling it threw the 1.5" conduit he already put in!

 

[outsider347]

For 60A it's too far for #2 Al. You should go with 2/0-2/0-2/0-1 MHF. Don't use the term SER with MHF, SER is a different cable.

Thanks for your response

Any suggestion where I might purchase the wire

ed

 

[pattenp]

You can try Lowes or Home Depot. But I think for the 2/0 MHF you need to go to an electrical supply. Also a bit of info is 2/0 will not fit in a 60A breaker. You'll need to use a splice/reducer to add short pieces of #2 to fit the breaker. The splice can be made in the panel box. There are other options for wiring such as using 2/0 Quadruplex URD for the long outside run and transitioning to #2 SER for entry into the buildings. The splicing will be done outside in junction boxes. URD is not fire rated so it cannot enter the structure.

Thanks for your response

Any suggestion where I might purchase the wire

ed

 

[Aceman]

Remember, #2 MHF has a max over current rating of 90 amps. With a 150 feet of #2 MHF, to maintain a 3% or less voltage drop, you need to keep the total load at about 72 amps or less. But on the flip side, the feed should be sized at least to 125% of the figured loads. So #2 MHF shouldn't be used if your loads will exceed 80% of the 90 amp rating, or 72 amps.

It doesn't hurt to size it that way, but it's not a code requirement. It's figured at 100% of noncontinuous plus 125% of continuous load. So you can have 90 amps of noncontinuous load on a 90 amp feeder.

 

[pattenp]

Yeah, I was trying to keep it simple.

It doesn't hurt to size it that way, but it's not a code requirement. It's figured at 100% of noncontinuous plus 125% of continuous load. So you can have 90 amps of noncontinuous load on a 90 amp feeder.

 

[SALIV8]

Got a link to that?

Chicago electrical code does not allow aluminum wiring in residential or commercial applications. NEC does allow it, yes. Home improvement stores dont even sell aluminum wiring in the city. Does aluminum work, sure. But it is not the best material for electric imo.

 

[SALIV8]

It's fully NEC compliant to wire your house completely w/ aluminum there are no restrictions to doing so other then AL is not made in smaller sizes.


Aluminum installed correctly is safe & reliable, copper installed incorrectly is just as dangerous as aluminum installed incorrectly.

NEC yes. Chicago electrical code does not allow aluminum.

 

[p_mori7]

I used Teck Cable for my supply.

90' run. 100A to the subpanel. No conduit required (except where it exits the building before it goes underground).

Copper.

Not cheap ($500 ish), but it was what I wanted.

http://www.texcan.com/products/teck.htm

 

[Charles (in GA)]

Chicago burned down because the cow kicked over the lantern, not because of a aluminum branch circuit to a range or stove (common use for aluminum in houses). Chicago also requires conduit everywhere, which borders on insane, and probably just a reflection on the number of rats there that can eat the insulation off of romex.

Fact is, virtually everywhere else in the nation follows the NEC and allows aluminum wiring when properly installed with aluminum compatible components. All breakers are AL and CU compatible, so its a matter of having the correct terminations on the device end.

Charles

 

[Charles (in GA)]

Why does it seem that people always bury the conduit first, then start asking what size conductors they should be using to feed their garage? Putting the cart before the horse it seems.

Charles

 

[SALIV8]

Chicago burned down because the cow kicked over the lantern, not because of a aluminum branch circuit to a range or stove (common use for aluminum in houses). Chicago also requires conduit everywhere, which borders on insane, and probably just a reflection on the number of rats there that can eat the insulation off of romex.

Fact is, virtually everywhere else in the nation follows the NEC and allows aluminum wiring when properly installed with aluminum compatible components. All breakers are AL and CU compatible, so its a matter of having the correct terminations on the device end.

Charles

Having wiring in emt is the safest way to wire. I don't think anyone will argue that. Use all the aluminum you want I don't mind. I would never use it no matter NEC minimum codes.. Don't forget you prefer metal halides and 500w halogen spotlights in your garage. Not what I would call a good decision.

Chicago has some of the lowest cases of electrical fires for a reason. Overkill is underrated especially when it comes to safety.

 

[Gooch]

Having wiring in emt is the safest way to wire. I don't think anyone will argue that. Use all the aluminum you want I don't mind. I would never use it no matter NEC minimum codes.. Don't forget you prefer metal halides and 500w halogen spotlights in your garage. Not what I would call a good decision.

Chicago has some of the lowest cases of electrical fires for a reason. Overkill is underrated especially when it comes to safety.

I'd venture that RMC would be safer than EMT. I'd also venture that the majority of electrical fires in homes are from old knob and tube wiring.

Like someone else said earlier, an improperly installed copper conductor is just as dangerous as an improperly installed aluminum conductor.

what are your concerns with aluminum wiring? specifics?