Aluminum Conductors Copper Ground

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zcanyonboltz

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I'm a running an overhead feed to a garage using quadruplex. My question is all conductors are aluminum #4. I have #10 copper left from another job...is it legal to use copper as the grounding conductor in the EMT although all other conductors are aluminum? I know this is not a parallel installation but I am thinking 310.10 (H) requires all conductors to be of the same material. I am using 60A breaker, 250.122 requires #10 copper and #8 aluminum. I am just trying to burn up some copper and am now wondering if my question is legal or not. The new houses I do we run #4 copper ground with 4/0 aluminum from disconnect mounted back to back with panel. I'm looking through 250.120 as I post. Thanks.
 
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texie said:
If this is overhead quadplex the messenger is the EGC. What is the separate #10 for?
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texie said:
If this is overhead quadplex the messenger is the EGC. What is the separate #10 for?
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# 10 will be in EMT coming out of panels on house and garage along with #4, quadruplex run between the panels. I'm running quadruplex because I don't want the grounded conductor to be bare overhead. I don't think I can use triplex because I want 240 at garage. Maybe I'm using wrong terms in reference to quadruplex and triplex.... is there 4 insulated wires in addition to messenger with quadruplex and then 3 insulated in addition to messenger for triplex?
 
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Quuadplex is 3 insulated with a bare messenger. This would be correct for a 120/240 feeder. The bare messenger is the EGC. You can use the #10 CU at each end to connect to the messenger. You will need appropriate CU to AL connectors.
 
texie said:
Quuadplex is 3 insulated with a bare messenger. This would be correct for a 120/240 feeder. The bare messenger is the EGC. You can use the #10 CU at each end to connect to the messenger. You will need appropriate CU to AL connectors.
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Thanks a lot! I'm glad I posted this.. You saved me from ordering quadruplex and not needing it, I appreciate that. I was thinking about it, 3 wire refers to 3 insulated conductors and ground so I just learned this applies to triplex as well. People on my site will learn this too as we talked this over and no one knew that.
 
zcanyonboltz said:
Thanks a lot! I'm glad I posted this.. You saved me from ordering quadruplex and not needing it, I appreciate that. I was thinking about it, 3 wire refers to 3 insulated conductors and ground so I just learned this applies to triplex as well. People on my site will learn this too as we talked this over and no one knew that.
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Hold on! If you are running a 12/240 feeder you need quadplex. That is 3 insulated plus the bare messenger. The insulated conductors will be line/line/neutral. The bare will be the EGC.
 
hbiss said:
Umm, you do need it. 2 hots, neutral and ground. Four conductors.

Quad means four. Tri means three.

-Hal
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See post #3. For some reason, he wants a separate, insulated ground conductor along with the triplex.
He seems to think the ground needs to be insulated (but apparently not the neutral!).
All bad ideas - quadruplex is required here as you state.
 
As Hal stated the terminology is important. Quadraplex is 4 conductors, triplex is 3 conductors, you need 4 conductors.

In answer to your original question yes you can use a copper EGC with aluminum conductors but you cannot use triplex with a bare neutral and a copper EGC.
 
infinity said:
As Hal stated the terminology is important. Quadraplex is 4 conductors, triplex is 3 conductors, you need 4 conductors.

In answer to your original question yes you can use a copper EGC with aluminum conductors but you cannot use triplex with a bare neutral and a copper EGC.
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Is a neutral in an aerial cable prohibited from being bare?
 
retirede said:
See post #3. For some reason, he wants a separate, insulated ground conductor along with the triplex.
He seems to think the ground needs to be insulated (but apparently not the neutral!).
All bad ideas - quadruplex is required here as you state.
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The only place the ground will be insulated is in the EMT coming out each panel. I clearly said this post 3#, I don't want the grounded conductor to be bare.
 
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texie said:
Hold on! If you are running a 12/240 feeder you need quadplex. That is 3 insulated plus the bare messenger. The insulated conductors will be line/line/neutral. The bare will be the EGC.
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Thanks for reply on this. Terminology...... I didn't read your post #4 close enough last night a lot of background activity as I was on forum. Thanks again.
 
You seem to be unhappy with our services. We are sorry. We will get you your money back.
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Not unhappy at all..I appreciate the discussion. I'm just making clear what I said in reference to post #8. But thanks for the refund.
 
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In my original post the question is this, there is nothing that prohibits a copper grounding conductor to share the same raceway as aluminum current carrying conductors? Answer, no, texi and infinity Thanks.
 
zcanyonboltz said:
In my original post the question is this, there is nothing that prohibits a copper grounding conductor to share the same raceway as aluminum current carrying conductors? Answer, no, texi and infinity Thanks.
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you can mix up "separate" conductors and separate segments of conductors all you want.

with paralleled conductors you must use same size, type, and any other characteristics that may affect overall impedance to each element of the parallel set. This to assure each element has same impedance so that current will divide evenly across each element, otherwise if one has significant enough difference you may find the lowest impedance element is carrying more than it is designed to handle even though the entire "set" is still below the presumed ampacity of the set.
 
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