Doubling over cable conductors

To double over or not to double over conductors? That’s the question.

Research references

• electriciansforms.net
• Best practices for CU (Consumer Units) PDF resource
• The IET (Institution of Engineering and Technology)
• electricianforum.co.uk

No one seems to mention multistrand doubling over. I only found resources for single core. There was some discussion about multistrand twisting strands together however.

Personal notes

• I have seen single-core doubled conductors snap if opened back out straight. Copper becomes brittle.
• Doubling helps with smaller conductor diameter when inserted into a large connection block.
• Multistrand “electronics” cable I always twist strands together then double over if required. Increases biting surface area. Multistrand is also less likely to becomes brittle in my experience.
• single-core don’t twist two conductors together because it’s a pain when adding an additional conductor into the connector block terminal. It also causes fatigue on the conductor. Double over can suffer when adding extra conductors to a connector block.
• single-core can be doubled over if it’s unlikely another connector will be added to the connector block. For example a light switch that controls one lamp. This is in agreement with the above PDF resource: “Where fitting one conductor only, double over the conductors”.

Summary

• Double over if the cable diameter is too small according to your personal digression.
• Multistrand should always have strands twisted together.
• Bootlace ferrule or soldering multistrand conductors for termination into connector blocks I will save for another blog post some time.