Final answer:
Option A, using care when placing a polarized plug into a non-polarized outlet, is not a good guideline because it contradicts the purpose of polarized plugs, which is to ensure proper connection and reduce shock risk. Polarized plugs, proper use of the three-wire system, and checking cords for damage are vital for maintaining electrical safety.
Step-by-step explanation:
The correct guideline for cord safety that should not be followed is A) use care when placing a polarized plug into a non-polarized outlet. This is because polarized plugs are designed to be inserted in a specific orientation to ensure that the live/hot and neutral connections are made correctly, reducing the risk of electric shock. Polarized outlets and plugs are a safety feature, and incorrect usage by forcing a polarized plug into a non-polarized outlet can lead to a hazardous situation.
Polarized plugs and the use of a three-wire system can help prevent electric shock. The ground wire in three-prong plugs provides an extra layer of safety, as it will cause the circuit to break if there's an issue, such as worn insulation on a live/hot wire making contact with the appliance casing. This prevents the case from becoming part of the electric circuit and significantly reduces the likelihood of shock.
Checking cords for damage before each use, limiting the number of cords in an electrical outlet, and correctly using polarized plugs and outlets are all good practices to ensure electrical safety and prevent hazards.