Attend a vocational school, training academy or other training program, such as through a company as an apprenticeship. Electricians receive on the job training, as well as some classroom instruction, which should contain a medium to high voltage training course. Make sure that the classroom teaches multiple types of splicing, such as with copper or aluminum conductors, or with rubber molding.
Let your employer know that you want to train in high voltage splicing. Since many electricians receive on the job training, you can work with senior employers to learn this technique. Due to the fact that splicing is only needed in special circumstances, such as when a cable has to extend through a small space, first learn the reasons when splicing is necessary within your work environment.
Attend a professional seminar that deals with high voltage splicing. Seminars can be offered through various companies and institutions, including American Trainco. Make sure that the seminar deals with Class 1 splicing, which is the type that works with high voltages.
Take a class on your own. If you cannot find a seminar, you may need to complete an entire course -- which can last weeks or months -- to get the training you need to work with high voltage splicing.
Pay close attention to safety information while completing your training. When it comes to working with high voltage, nothing is more important than safety. For example, a crimp or compression feature on a conductor will increase the safety of the process. Also, using a tape without a liner that is designed for high voltage splicing with also help.