In Spain, What does reverse polarity mean, and how does it affect me?

Reverse polarity is basically when the live and neutral cables are the wrong way around, in Spain this is something that can occur regularly. I have found that very often, the supply cables from the electrical company are often the wrong way around. Most electrical items will work normally, no matter what polarity you have, and the 2 pin plug that we have here proves that fact as you can plug an appliance in any way you like, but certain items, for example extractor fans, may blow instead of suck. It is also important should you be working on the electrics in your house or even changing a light bulb. In a lot of cases by switching off the light switch you would assume that the lamp holder at the light fitting was dead, however if the polarity is reversed this may not be the case.

Many electronic items such as computers, have small fuses at the point where the electricity enters the appliance, this is to protect against an increased power supply (power surge), . It is at the point of entry into the unit to protect the circuit board, in the event of a fault the fuse will blow protecting the important stuff inside, . If however you have reverse polarity the circuit board may get fried before the fuse blows, as the electricity passes through the circuit board first.

It can also mean that certain appliances are not earthed correctly,. In some systems the earth is connected to the neutral and if the polarity is reversed then the earth could become live, although these types of appliances are rare in the home.

You can test for reverse polarity using an electrician’s neon screw-driver; at a light pendant type fitting, the centre pin should be live. If you are unsure of how to check any electrical circuits or systems seek help from a professional electrician. 

Electricity is an essential part of modern day life and ensuring it is installed safely, is part of the job.