TransWikia.com

Reverse polarity on outlets, any negative side-effects?

Home Improvement Asked on July 3, 2021

I’ve lived in a variety of different places where polarities have been different on a per-outlet basis, ie the neutral is where the hot should be. I’ve never noticed any ill effects from this.

Are there any side-effects of having the polarities reversed? My understanding is that almost any AC device out there will just simply flow the other way if the polarity is backwards.

3 Answers

There's no danger to the attached load. AC current reverses direction 50 or 60 times each second depending on what country you're in.

It literally makes no difference at all for the equipment.

Human safety is another matter. The hot/line conductor is generally dangerous if you touch it, while the grounded ("neutral") conductor is generally (not always) safe. However, if equipment has a single-pole switch, it is only breaking the conductor it assumes is the line conductor. If you have the line and neutral reversed, then the appliance is still energized even if the switch is off.

Correct answer by Craig on July 3, 2021

You're correct that in an AC system, the electricity flows both directions and therefore will allow items to function.

However, these items can't be regarded as safe.

When two wires come into a device, and it has a switch, the switch is designed to interrupt the hot wire. If the polarity were reversed and the switch on the device were turned off - it would be interrupting the grounded (neutral) wire. This means if you turned off a light and stuck your finger in the bulb receptacle (Safety note: I don't recommend it.) You could be providing a ground-fault current path and complete the circuit!

Answered by Ramrod on July 3, 2021

The relative voltage between hot and neutral is constantly reversing but that doesn't mean that the two conductors are the same. Relative to earth the hot is varying (both positive and negative) while the neutral stays at roughly zero voltage relative to earth.

In particular if a single pole switching or protection device ends up in the neutral due to reverse polarity it can leave the appliance in an "off but live" state which is undesirable. A single pole protective device that ends up in the neutral also can't provide any protection against faults to earth.

It is possible to design applicances that meet safety requirements even if live and neutral are reversed and most modern appliances are likely to be built this way since in many parts of the world unpolarised plugs are the norm.

However if you live in a country where correct polarity is expected (such as the US and the UK) you should respect that expectation to ensure that all equipment is safe, even older equipment or equipment that was built in your country and never intended to be exported.

Answered by Peter Green on July 3, 2021

Add your own answers!

Ask a Question

Get help from others!

© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP