Reversed Polarity–Home Inspection Findings

Electrical Reversed Polarity Issues:

Everything works just fine, however my home inspector informed me that some of my electrical outlets have reversed polarity and should be rewired. Why is polarity an issue?

Polarity can be confusing. Within 120-volt household circuits, if the polarity is correct, the black wire is the hot wire and the white wire is neutral wire (grounded conductor). If the polarity is reversed the white wire is hot and the black wire becomes the neutral.

Some appliances have only two prongs and no ground (U-shaped) prong. Polarized appliances have a wide (neutral) blade and a narrow (hot) blade. This configuration fits with (grounded) receptacles with the same configuration. Problems occur when do-it-yourself homeowners forget that the brass screws on an outlet are for hot (black) wires and the silver screws are for the white(neutral) wires and the green screw is for the (ground) green wire

Polarity Matters:

With some appliances polarity doesn’t matter as with a clock for example. However with a lamp socket the electricity is intended to flow from the button on the bottom of the light bulb ( black hot wire) through the filament and back through the threaded collar (white neutral wire) to the neutral at the distribution panel box. If there is no bulb in the socket and the switch is on there is a greater chance of touching the threaded portion of the socket (or bulb) than the button on the bottom. If the polarity is reversed this threaded portion becomes the hot (live) side of the circuit and there is greater risk of electrical shock.

Polarity matters with appliances that have switches. When the appliance is plugged in the power should only go as far as the switch. If the polarity is reversed the power goes through the entire appliance and then back to the switch. If a loose wire in the appliance comes in contact with the outside case, the entire appliance becomes potentially “hot” electrically speaking and the risk of shock exists even though the appliance is not turned on.

For safety sake:

To keep yourself and family safe, if your home inspector indicates a reversed polarity situation have a qualified electrician check the wiring and make sure that this issue is resolved.

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