Aluminum wire and plastic conduit or copper and metal?

Furd said:

The electrical codes are not items of uncertainty, belief or imagination ...

Click to expand...

I understand, and I do not proceed until my own uncertainties and unknowns have been resolved.

220/221 said:

Even if you are not yet required to pull a ground, pull a #8 anyway.

Grounding = good.

Click to expand...

That makes sense to me, and I might just do that. Thank you.

220/221 said:

I recently re pulled 3, 4's + ground into an existing 1" EMT and it was NOT easy. An inexperienced person couldn't have done it without damaging the wire. Wires cannot twist or kink at ALL or they take up too much space.

Run 1.25 or 1.5.

Click to expand...

I have yet to put the wire and EMT side-by-side, but I will take a good look and do the computations before hanging anything. I only have to go about 20' before my first turn, then another 20' before turning again and then turning up to the subpanel, and I can put that last turn in place after-the-fact, if necessary. Also, this is not my first time pulling wire.

jwelectric said:

Anyone want to bet that this is what he is installing?

click here

Click to expand...

No, that stuff was #6, and I have #4.

I greatly appreciate everyone's help here, and I especially thank you, Jar546, for responding to this thread at all after others had either ignored or missed it entirely. I would have preferred to just ask simple questions and get straight answers -- Aluminum and plastic or copper and metal? -- but even antagonists can end up being helpful.

Peace.

I have yet to put the wire and EMT side-by-side, but I will take a good look and do the computations before hanging anything. I only have to go about 20' before my first turn, then another 20' before turning again and then turning up to the subpanel, and I can put that last turn in place after-the-fact, if necessary. Also, this is not my first time pulling wire.

Click to expand...

Still need some clarification for grounding purposes and for all purposes for that matter:

1) What code cycle are you under?

2) Is the garage attached or detached (conflicting posts)?

3) Will the conduit be run underground or above ground?

4) Will the conduit if run above ground be subject to the weather?

5) Are your pull points from beginning and the end only or do you have pull points in between start and finish too (real pull points)?

6) Will the installation get inspected by local authorities during or at completion?


If the job is not going to be inspected then I refuse to assist you with anything further.

Without ALL of those questions answered above, no one can really help you or give you guidance.

Either you want help and realistic, actual guidance or you want people to tell you what you want to hear regardless of the actual situation.

Safety first. People have died doing what your are plannin on doing.

installation

1. originally you were debating aluminum or copper, but the aluminum would have required a larger breaker.
2. Originally you were debating 1" or 1 1/4" conduit.
3. Then you debated whether the copper wire would support 100 amps, which is the same breaker you would have needed for the aluminum wire.
4. Now you are sticking with the 60 amp breaker which does not need the same wire as the 100 amp one would have.
5. Now you say you have the 100 amp wire and the conduit, so why are we still discussing it.
6. Since there is little possibility that you will ever reach the 240 v, 60 amp plateau, why worry about oversizing the wire?

hj said:

1. originally you were debating aluminum or copper, but the aluminum would have required a larger breaker.

Click to expand...

Yes, I believe my 60-amp breaker would not have accepted #2 wire.

hj said:

2. Originally you were debating 1" or 1 1/4" conduit.

Click to expand...

Yes, I was wondering what size conduit I would need after deciding about the wire.

hj said:

3. Then you debated whether the copper wire would support 100 amps, which is the same breaker you would have needed for the aluminum wire.

Click to expand...

Yes, and when I discovered I could not afford 100-amp copper, I settled for the #4 that will easily carry all the current my existing 60-amp breaker will allow through.

hj said:

4. Now you are sticking with the 60 amp breaker which does not need the same wire as the 100 amp one would have.

Click to expand...

Yes.

hj said:

5. Now you say you have the 100 amp wire and the conduit, so why are we still discussing it.

Click to expand...

Other than for the sake of some folk's desire to trash me or whatever, I have absolutely no idea! My questions have all been answered:

Three strands of #4 copper inside 1" EMT as a ground will easily carry 60 amps for 50' to my attached workshop's subpanel and be completely legal here where I happen to live.

hj said:

6. Since there is little possibility that you will ever reach the 240 v, 60 amp plateau, why worry about oversizing the wire?

Click to expand...

I was not actually worrying about that, but at least now I know the wire is quite sufficient.

Dear Sir,
I am a licensed Master Electrician. Funny you are asking this question as I am currently adding a 100 ampere sub-box in my own workshop which is also about 50 feet from my main box. I already had some 2 gauge alum. twisted duplex wire taken down from a power drop. First let me say that if you can afford the copper wire, then that is your best bet. Second, if you can't afford the copper wire in your project budget, then the alum. wire is fine. Just keep in mind the alum. wire does not conduct as well as the copper so we must treat it differently. Since I already have the #2 alum. I'm going to use it myself. When using alum. wire you must remember it will emit more heat at full load than the copper. There fore up size your non-metallic conduit (PVC) on size to allow more room for the wire to "breath." I choose to use 1 1/2 PVC conduit. The number of turns doesn't matter as long as you have wire pull access along the way. Never put more than 270 degrees of turns under a floor or underground as you will not be able to pull wire through it. #2 Alum. is rated at 124 amps of current in a raceway or conduit. When I design and build anything electrical, I always try to design the equipment to never run at more than 80% full load on the amp rating of the materials. In other words, if the wire is rated at 124 amps, then a 100 amp breaker feeding the wire is perfect. Be sure to drive an 8 foot copper ground rod at the new sub-box. You only bond the neutral and ground at the main box. All sub boxes should have the neutral and ground buss bars separate from one another. Just remember the main job of the breakers is to protect the wire and equipment down stream from being over loaded which could cause fire. Never use a larger breaker than the wire or equipment it is feeding is rated at. Even better, don't exceed the 80% load factor and you will never have problems kicking breakers. Also when using alum. wire don't forget the Anti-ox grease in the wire connection points. Alum. expands more than copper when it heats up, the grease will help insure a good non-oxidized connection. I hope this helps!

quote; #2 Alum. is rated at 124 amps of current in a raceway or conduit.

My book says 3 #2 alum in a conduit is limited to 75 amps.