35年后，我决定取悦夫人。用新的jenn空气烹饪用新的剑桥取代。当我检查现有连接时，＃6 al电线连接到＃8 cu。带有常规扭转连接器的炉灶的电线。我不是任何意思是专家，但我意识到这是一个否。有趣的事情是毕竟这些年来没有关于连接的氧化，或任何过热的指示。除此之外，我想做正确的事情，但已经无法在连接器上找到一个解决方案，足以加入＃6 al和＃8 cu。任何建议都将非常感谢。
After 35 years of use I decided to please the Mrs. by replacing the old Jenn Air cooktop with a new one. When I examined the existing connection the #6 Al wires were connected to the #8 Cu. wires from the cooktop with regular twist connectors. I am not by any means an expert but I realize this is a no no. Funny thing is after all these years there is not a hint of oxidation on the connections, or any indication of overheating. That aside I want to do things right, but have been unable to find a solution online on connectors big enough to join #6 Al and #8 Cu. Any advice would be sorely appreciated.
Aluminum is common in this larger wire, and often, connections are made to screw-down lugs. In fact the lugs are often made of aluminum.
So first, check the lugs on the range and see if they're already listed for aluminum. If not, it may be possible to get lugs that are.
Alternatively, you can get a wide variety of screw-lug splices for aluminum. That's all an Alumiconn is - an exceptionally small lug. The above link explains why they work. This type of screw lug is also the standard wiring method in Europe. Here are photos of Alumiconn; a larger lug connector (see the resemblance), and the Euro style. Lastly, here's the split bolt that ThreePhaseEel is referring to.
But the best way to please the Ms. is make sure you have a separate ground wire. 35 years ago, the common practice was to not bother running an equipment safety ground, and simply hijack neutral as ground. This is still permitted in old-work because of lobbying by appliance makers. But it's a terrible idea; if the neutral wire has a problem, the 120V loads in your range pull neutral up to 120V - and since neutral is tied to ground, this energizes the chassis of the machine at 120V. Touch the range and the sink, and you're dead. The good news is it's totally legal to retrofit just a ground wire and keep the conductors.
You should get the proper connector rated for connecting aluminum and copper. These may be $5 each but you will have done it according to code.
However, as your experience shows, the correct size of a good brand of twist-on wire connectors (e.g., Scotchloks) can make a good and lasting connection between copper and aluminum conductors. What was the color of the plastic on the wire nuts connecting your cooktop? I think the blue ones are rated for #6 Cu to #8 Cu. The next size down is grey color coded and is rated for two #8 stranded Cu.
Our range was connected this way by the builder and there was no sign of damage when I replaced the original range. I put in a 4-wire receptacle and use a 50-A rated cord and plug.
A hard wired connection with wire nuts can be made more secure with a suitable antioxidant paste such as Penetrox from Burndy, applied correctly. The paste is applied to the aluminum conductor and then the surface is abraded with emery cloth through the paste. The wire nut is filled with paste and then screwed onto the aluminum and copper conductors.
To make it clear I am not recommending that you use anything but connectors rated for aluminum to copper in the size of these conductors. I just didn't want you to think you had necessarily dodged a bullet.
Edit The wire-nut connection was inside a metal box which was loose at the end of 3 or 4 feet of wire coming out of a hole in the wall.
Another Edit The Ideal purple connectors are officially rated for Al to Cu connection, but are not well thought of by aluminum wiring expert Jesse Aronstein. See http://inspectapedia.com/aluminum/Aluminum_Wire_Repairs_Not_Recommended.php