Underwriter’s (Electrician’s) Knot
The underwriter’s knot provides strain relief of electrical wiring. Electrical appliances have it to protect the terminal connections inside them. It is mainly used by electricians where they suspect rough treatment of wiring like in floor and table lamps. Presumably, it was given the name underwriter’s knot by fire underwriters who knew the importance of the knot in preventing the danger of electrocution and fire.
How to Tie an Underwriter’s Knot
The diagram shows you the step by step tying procedure of the knot in a two strand wire.
- Preventing the cords of electrical appliances from becoming loose at the socket connections on pulling.
- For re-wiring a light fixture or lamp.
The video shows you how to make the knot without the initial turns as shown in step 1 of the diagram above.
How to Tie an Underwriter’s Knot Step by Step
- Twist the red and blue wires 3 times around one another
- From a loop with the blue wire
- Take the red wire down
- Pass it through the blue loop
- Twist the ends around the terminals
- The knot is complete