What is the best way to join electrical wire?
A question I am often asked is, ‘what is the best way to create an in-line wire to wire connection?’. I like this sort of question as it is good to be part of the design process and to help people with making the best decisions for them.
Depending on the specifics, there are many options available. Let’s take a look at my ‘Top 5’ ways to create a cable joint:
1: Crimp Splice
The In-Line Crimp Splice is simple and requires minimal tools. These handy splices are great for simple connections and are very popular in electrical installations. Although the crimp splice is not waterproof it is simple, and if you have to make a cable connection in an environment where there is no mains power all, you need is a hand crimp tool.
2: Solder Sleeve
Solder Sleeves are similar to the Crimp Splice; however, they have the added benefit of having an inner lining of solder that creates the joint when being heated. The outer jacket is a heat shrink material that, by shrinking down to the diameter of the cable, creates a basic environmental barrier. A good example of the use of a solder sleeve is splicing a piece to wire to the braid of a multi-core cable. The Solder Sleeve is robust, simple and effective but does need to be used by an experienced trained assembler; this is because the combination of heat and the fact that you only get one shot to install these means they must be assembled correctly to work effectively.
3: Terminal Block
We have all seen these and, if you have plenty of space and a screwdriver, these are the simplest way to create a connection. Mostly used in power cables, they can be used for any cable to cable connection. Simple and easy and you can get these anywhere!
4: Ultrasonic Weld
The ultrasonic welding process takes place in a solid state, without any melting of the parts being joined. This is accomplished by overlapping the weld metals and rubbing them against each other using low pressure and high frequency mechanical oscillation. Within a fraction of a second a permanent, solid and pure connection, with outstanding physical properties, is created.
As a rule, all non-ferrous metals are suitable for this joining technique, however, copper, aluminum and their respective alloys are particularly well-suited.
The method of Ultrasonic welding is the strongest and most reliable, however it is also the most expensive, requiring the use of incredibly expensive machines.
5: Solder
Solder is the easiest one of the strongest and lowest cost methods of joining cable. This quick and simple method is the most widely used because it is simple and effective, and it also has the added benefit that it takes up very little space.
While a solder joint is not flexible and must be assembled correctly it is my personal favorite. There are many different types of products on the market , but all of the above are by far the most common you will be likely to come across.
If you are not sure which is best for you then fear not – your helpful cable assembly experts will be there and happy to help you!
The "best way" is to replace all the damaged wire.
Either completely (from where it starts and ends now) or by adding two junction boxes (which must remain accessible) where you can join the undamaged parts of the wire to new undamaged wire between the two junction boxes. If you can reach one end with new wire, you may only need one new junction box.