Aluminum Wire Pigtail Connectors

Purple Wirenuts vs AlumiConn Lugs

When it comes to pigtailing aluminum wiring to copper wire, there are several options available to use. We focus on the easily available solutions which are Purple Wirenuts (Model 65) and AlumiConn Lugs. I’m leaving out the CopAlum Crimp because it’s not easily available to everyone.

Note: The U.S Consumer Product Safety Commission only recognize CopAlum and AlumiConn Connectors as meeting the agency’s standards regarding preventing fire hazards as of March 15, 2011.

Before these connectors, pigtailing involved pouring some No-Lox liquid into whichever wirenut you needed to install. Purple wirenuts then became the accepted solution for Aluminum/Copper connections having antioxidant liquid pre-installed and a flap-style system at the base to prevent run-out. AlumiConn Lugs are now our standard solution for Aluminum/Copper connections for several reasons:

  • UL Listed
  • The Aluminum and Copper wires never come into direct contact
  • Solid Connection


  • Max Voltage – 300v AlumiConn : 600v Purple Wirenuts
  • Wire Size Range – Minimum #18/Maximum #10 for both
  • Temperature Rating – 105 degrees C for both
  • Flammability Rating : V-2 for both
  • Maximum Wires per Connector – 3 for both
  • King Innovation AlumiConn Lugs and Ideal Purple Wirenuts are Made in the USA

Installer Pros and Cons:

Installation Time:

Purple Wirenuts twist on quick and installation is easy. AlumiConn Lugs are a bit more time consuming with having to unscrew each port and then tighten each port. Plan on spending up-front time prepping the lugs, it will speed up installation.


Both Wirenuts and Lugs take up considerable space. Purple wirenuts take up slightly less than AlumiConn Lugs. Considering that most homes with aluminum wire also have smaller metal boxes, this can become an issue. Standard switches and outlets aren’t usually an issue but GFCI outlets and dimmers will often not fit when using aluminum/copper connectors. Plan on installing a GFCI breaker for bathrooms/kitchens or removing the old metal boxes and installing a new plastic remodel box, or adding an extension for space when bringing those areas up to code.


Purple wirenuts will occasionally not grab your wires but for the most part are reliable. AlumiConn lugs are solid and the only complaint is the occasional lug port is pre-set just a bit too tight.


A main reason for using AlumiConn lugs is the fact that the copper and aluminum wires don’t make direct contact. AlumiConn keeps the dissimilar metals from ever directly contacting one another.


We prep AlumiConn lugs up-front with a variety of leads (wire size and colors) and loosening the ports for improved installation time. As with any installation, make sure not to strip the wire too much or have any exposed metal remaining on connections. Wirenuts can be stripped longer for wirenut installation, AlumiConn lugs have a smaller strip size to keep leads from being exposed. Keep in mind your amp rating and sizing for aluminum and copper to help your installation time.

20amp Circuit = #10 Aluminum and #12 Copper THHN

15amp Circuit = #12 Aluminum and #14 Copper THHN

AlumiConn Lugs

One wire per port/three total

#12-#10 Solid Aluminum

#18-#10 Solid or Stranded Copper

Purple Wirenuts

1 #10 AL sol. w/1 or 2 #10 CU sol.
1 #10 AL w/1 or 2 #12 CU
1 #10 AL w/1 or 2 #14 CU
1 #10 AL w/1 or 2 #16 CU
2 #10 AL sol. w/1 #12 CU
2 #10 AL sol. w/1 #14 CU
2 #12 AL sol. w/1 #10 CU sol.
2 #12 AL sol. w/1 #10 CU str.
1 #12 AL sol. w/1 or 2 #10 CU sol or str
1 #12 AL str. w/1 or 2 #10 CU sol.
1 #12 AL w/1 or 2 #12 CU
2 #12 AL sol. w/1 #12 CU
1 #12 AL w/1 or 2 #14 CU
2 #12 AL sol. w/1 #14 CU
1 #10 AL w/1 or 2 #18 CU
2 #10 AL sol. w/1 #16 CU
2 #10 AL sol. w/1 #18 CU
1 #12 AL w/1 or 2 #16 CU
1 #12 AL w/1 or 2 #18 CU
2 #12 AL sol. w/1 #16 CU
2 #12 AL sol. w/1 #18 CU

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