1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

CCA wire vs OFC wire, my experience

Discussion in 'General Electronics Chat' started by Mosaic, Nov 17, 2017.

  1. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE
    Well, here it is:
    1-degraded CCA wire.jpg
     
  2. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

    Joined:
    Nov 17, 2003
    Messages:
    39,331
    Likes:
    653
    Location:
    Derbyshire, UK
    ONLINE
    I'm a little bemused by this :D

    Aluminium wire is crap, everyone knows that - and what's with the 'oxygen free' rubbish, that's just a marketing term used by HiFi advertisers to con the gullible.
     
  3. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

    Joined:
    Jun 21, 2006
    Messages:
    6,070
    Likes:
    524
    Location:
    Cleveland, OH, USA
    ONLINE
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE

    If everyone knew that then there wouldn't be such a large market for it, would there?
     
  6. Diver300

    Diver300 Well-Known Member

    Joined:
    Oct 19, 2007
    Messages:
    3,090
    Likes:
    102
    Location:
    England
    That length of wire of that cross section should be <5 mΩ in aluminium, and <3 mΩ in copper. At 6 A the heat dissipated should be <0.2 W with aluminium and < 0.1 W with copper.

    Those resistances and powers are completely irrelevant compared to the imperfections in the terminations. The fact that the copper wire has a resistance of 12 mΩ shows that the termination resistance is larger in the real world.

    Anyone who is trying to save fractions of a penny on 5 cm of wire by using CCA instead of copper, or who is trying to hide that the wire is cheap by using CCA which is fatter for the same resistance, isn't going to be making the connections properly. It could also be that the wire had been bent too much on installation, and aluminium would crack strands more easily than copper.

    Aluminium has its uses in conductors. Some cars where the battery is in the back have an aluminium conductor to go to the starter motor. Aluminium is less than twice the resistance for the same area, so under twice the volume needs to be used. However, aluminium is less than a third of the density of copper, so it ends up at just over half the weight of the copper. (values from Wikipedia). Obviously the insulation is larger so it weighs more to insulate the aluminium, but the larger cross section and lower weight means that the conductor needs fewer supports. Also in car construction, the connectors are put on to the conductors using the right tooling and techniques, so bad connections aren't likely.
     
  7. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE
    That wasn't the reason, there is a lot more of that wire used in the application as it was selected based on specified conductivity. HOWEVER, galvanic corrosion and thermal stresses introduced by dissimilar metals in heat generating electrical contact are not in the wire specs and appear to be significant. Notably I am seeing levels of corrosion across all the CCA installations which imply it's probably best to avoid using it in PWM apps.
    To clarify, while the average current may be 6A, the wire was carrying PWM of around 15 to 18A.
     
  8. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

    Joined:
    Oct 30, 2010
    Messages:
    9,970
    Likes:
    1,099
    ONLINE
    The only use of CCA wire I used was for RG-6 which was copper clad aluminum. I got 1000' of it for free. Honestly, I did not realize it was CCA until much later. It is a slight issue because the rotor I use is powered from an RG-6 cable. RF is going to travel along the skin anyway.
     
  9. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

    Joined:
    Nov 17, 2003
    Messages:
    39,331
    Likes:
    653
    Location:
    Derbyshire, UK
    ONLINE
    What makes you think there is? :D

    I don't know as you can even buy aluminium wire in the UK?, with perhaps the exception of 300KV cables for pylons, which often use aluminium for weight and cost reasons.
     
  10. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE
  11. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE
    >>
    Alibaba.com offers 24,256 copper clad aluminum wire products. About 96% of these are electrical wires. A wide variety of copper clad aluminum wire options are available to you, such as bare, insulated. You can also choose from solid, stranded. As well as from pvc, enameled, and rubber. And whether copper clad aluminum wire is heating, overhead, or underground. There are 24,214 copper clad aluminum wire suppliers, mainly located in Asia. The top supplying countries are China (Mainland), India, and United States, which supply 99%, 1%, and 1% of copper clad aluminum wire respectively. Copper clad aluminum wire products are most popular in South America, Eastern Europe, and North America. You can ensure product safety by selecting from certified suppliers, including 6,955 with ISO9001, 2,689 with Other, and 854 with ISO14001 certification.<<
     
  12. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

    Joined:
    Nov 17, 2003
    Messages:
    39,331
    Likes:
    653
    Location:
    Derbyshire, UK
    ONLINE
    No, but we probably have the worlds best electrical system - which probably explains the lack of aluminium wire :D

    Did you fit the original wire?, and if so WHY??? - why would anyone with even a slight knowledge of electronics/electrics use a massively sub-standard product?.

    Assuming you didn't fit it, presumably you didn't know it was there? - or you would probably have replaced it, with something more suitable, before it failed.

    I notice the list of countries you mentioned are all well known for their fairly poor electric systems :D
     
  13. Mosaic

    Mosaic Well-Known Member

    Joined:
    Jun 3, 2010
    Messages:
    2,620
    Likes:
    129
    Location:
    Caribbean
    ONLINE
    There's also some secondary fallout from the metal corrosion shed from the CCA wire. Notice the zinc plated 6-32 MOSFET screw has started to corrode as well. The MOSFET next to it (with the good screw) carries the identical current as one of the series pair is configured as a drain to source polarity limiter.
     

Share This Page