Call me old school, but I am not a fan of some of the new friction grabbing splice devices out there. Similar spring connectors have been used on spec grade outlets for many years for 14awg copper. I have seen many failures and intermittent connection problems with these push springs. My theory, and just a theory mind you, is that there is not enough actual contact surface between the wire and the connection device and that the contact tension cannot be tightened. Over time expansion and contraction of the wire, surface tarnishing and dust can compromise the integrity of the connection. This happens with copper and much more with aluminum. As the surface area of the connection shrinks from any of those factors, heat and arcing can be created in the connection. Eventually failure can result. If you look at the comparison with a good wire nut or screw fastening terminal strip, you will see that there is much more metal to metal contact, the conductors can be twisted together and the tension can be tightened at any time with a twist or a turn of a screwdriver.

An other concern I have is the use of these type of connectors with aluminium wire. I have had nothing but bad experience with alu branch feeder wiring over the years. You must be absolutely sure the device is Al/Cu rated at minimum and that connections are as tight as possible. On larger wires such as service entries where alu wire is still used regularly, a substance known as NOLOX is always used on these connection to fight corrosion and assure good conductivity between the wire and landing connector. I also use NOLOX on any dryer or range connections that have alu wire. Alu wire tarnishes very quickly and expands and contracts faster and more than copper, therefore needs to be secured firmly and protected from corrosion wherever possible.

The last reason I am not a fan of friction fit connectors is that they can be miserable to work with after initial installation. Yes, they are fast easy to install the first time, but if you need to modify a connection or trouble shoot a problem where these connectors are installed, it is pain if not impossible to remove wires temporally. Reinserting a wire often doesn't have the same grip as before.

I may be all wet on this one, but I'm not ready to give up my trusty high quality wire nuts and screwdriver yet.

Use the right connector

Ideal Industries makes a few different varieties of twist-on wire connectors that can handle 6 conductors. After looking through the UL Listed Combinations (PDF) document, I was able to find 4 such connectors.

• Wing-Nut 452 Wire Connector, Red. Which accepts 1 to 6 #14 conductors.
• Twister® PRO Wire Connector. Can also handle 1 to 6 #14 conductors.
• Wing-Nut 454 Wire Connector, Blue. Can take 5 or 6 #14 conductors.
• Twister 342 Wire Connector, Gray. Allows 3 to 6 #14 conductors.

If you find yourself needing to connect more than 6 conductors, it's probably time to start looking for something other than a twist-on wire connector. As @Aaron pointed out, you can use a Push-In type connector for up to 8 conductors. You might also want to consider using a Crimp Connector, which can connect 4 to 10 #14 solid conductors (an insulated cover would be required when joining current carrying conductors).

Moving beyond crimp connections, you'll likely have to start looking at terminal blocks, bus bars, design changes, or alternative solutions.

_{^{All conductor combinations will vary from manufacturer to manufacturer, check the manufacturers documentation before using any electrical connector}}

Use devices as connectors

Another option, is to use unused terminals on devices as splice points. For example, you might have a switch with both side and back terminals. Using the back terminal as a splice point, is an acceptable way to extend the circuit. In fact, some industrial grade receptacles (like the Leviton 5252 Series) offer 8 clamp style terminals on the back of the device.

Reduce the number of pigtails

Where multiple devices share a single hot wire, you can reduce the number of wires in a twist-on type connector by using a single extra long pigtail. You'll use the extra long pigtail to connect all the devices, eliminating the need for a single pigtail per device. So you can take the number of required pigtails from 3, down to 1. If you leave the feed hot extra long when originally wiring the circuit, you may be able to eliminate pigtails altogether. To do this:

1. Remove a bit of the insulation in the middle of the wire.
2. Wrap the exposed wire around the terminal screw of the first device, and tighten the screw.
3. Remove a bit more insulation further down the wire.
4. Wrap the exposed wire around the terminal screw of the next device, and tighten the screw.
5. Repeat until all devices are connected.

Once you have all the devices connected in this manner, you can use the end of the wire to feed through to other devices. Simply remove a bit of insulation at the end of the wire, and use a twist-on wire connector to connect this wire to the wires feeding the other devices.

Daisy chain

As for connecting bundles of wires with pigtails. There's no problem doing this, as long as you don't exceed individual connector conductor fill, or overcrowd the box.