First off, let me give a huge thank you to our Inspector Wilmer Mollfulleda for supplying these wonderful pictures on cut multistrand wires. Just as an fyi, you can always request your inspector when you schedule with us.
Now back to your regularly scheduled programming…
MultiStrand Wires & Circuits
These wire types, as seen on the featured image of this post, are often used for larger appliances like A/C systems. This is because A/C systems need a thicker wire to supply more power. A multi-strand wire will be more flexible than a solid wire of the same size.
Therefore, when wires need more flexibility and maneuverability electricians will opt for the multi-strands. Read more about wire gauge standards.
Can You Cut Multi-Strand Wires and Circuits?
The cut on multi-strand in the featured image of this post was used on a brand new home. Think about that while we discuss if this is even allowed on a home…
So can you cut them to fit a multi-strand inside a breaker? No. Why?
Multi-strand circuits should be treated as a solid wire. Each strand is important in carrying the electric load. If you were to cut some wires in the strand, this forces the electric load to finish the circuit through one strand.
If each multi-strand wire is made up of 7 strands (the most common instance), then, the load normally split is now forced to go 7 times the normal amount of load.
How Does This Affect Electric Currents?
Well, the power will be forced through one strand in order to complete the circuit. However, with a smaller wire, the resistance increases. Too much resistance for a current can burn out a wire, spark, and cause a fire.
So, cutting multi-strand circuits in order to attach them to a breaker can cause fire.
Another Incorrect Solution For Attaching Multi-Strand Wiring: Parallel Circuits
So would this be a correct solution rather than cutting a multi-strand wire to fit in an electrical panel? I would suggest this is a better option than actually cutting the wire, however, again this is not the proper way to connect a multi-strand wire.
In this instance, you are splitting the current between the two sets of strands which can again cause overheating since electric current may not evenly split between the two sets.
What Is The Correct Solution For Cut MultiStrand Wires?
The correct solution is to fit all strands under one connection point within a breaker. In some instances, a different breaker may be required in order to fit a multistrand of that size.
Here is an example of a Square D Breaker, on this site, they express the wire size allowed.
You can also check out this wire size guide to check which breaker you will need for the size wire.
Cutting multi-strand wires should not be allowed in your electrical system. You should always look and read manufacturer’s instructions on correct circuit breaker sizes needed, wire sizes, and consult a licensed electrician.
If you have questions, comment below! We would be happy to help!