Faulty Extension Lead? Signs of when to replace

1) Is the photograph showing a safe extension lead?

Single colours on display like this outside of an electrical enclosure give rise to danger. The basic insulation we see here does not afford proper protection against everyday life and its knocks and bangs. It is far too easy for a faulty extension lead like this one to become a dangerous extension lead. These things are not particularly expensive and can be bought from many reputable retailers for a few pounds. Make sure you check your extension lead over thoroughly every 6 months if it is in permanent use. Best to do it when the clocks go forward or back to help you remember. 

The extension lead in the photograph had not only been badly strained but had also had a drink thrown over it and was causing power loss to the whole property! These leads are often shoved behind furniture or under tables and beds. The trouble with this is these environments are difficult to get a hoover or mop underneath and as a result lots of dust can build up, fill up the plug socket holes in the lead and cause it to become a faulty extension lead. 

2) What are Extension Leads?

Extension leads are a common device found in homes to enable the expansion of a single socket outlet into several socket outlets or to enable a socket outlet to be temporarily extended to another part of the home or outdoors. They have a plug top and cord along with (usually) a number of extra outlets. 

The extra outlets that an extension lead can supply ranges from 2 to virtually unlimited.  I have personally purchased and used a 12-way extension lead. 

The additional outlets that the extension lead supplies are sometimes individually controllable such that some of the outlets can be turned off, whilst others are on through  individual switches.

3) Does my extension lead need replacing?

There are several signs that an extension cable or power strip would need replacing or is in some distress. If any of the following issues seem to be happening with your device then it should be inspected professionally or potentially replaced. 

• Signs of melting or heat damage to the cord, plug or power strip.
• Discolouration around the pin holes for plugs, cable or plug top
• Bare wires or coloured insulation on cables is now on display
• Some sockets are not working
• Plug tops are very difficult to insert into the power strip body
• Crackling noises
• Burning smells
• On/Off switches on the power strip fail or are difficult to operate
• Replacing fuses in the plug top regularly
• The extension lead trips the electric supply.
• Electrical shocks from appliances or nearby possibly due to poor or missing earthing

Any of these signs indicate that the extension lead is failing, may be dangerous and potentially requires replacing. Make sure to double check that you are not overloading the extension lead with electrical equipment that is too powerful. 

4) Extension lead making crackling sounds?

If you find that your extension lead is making a crackling sound then this is likely to be electrical arcing and sparking inside the lead or at the wall outlet. This is normally due to loose connections or damaged internal components. Failure to repair or replace the device could lead to further issues like a short circuit (dangerous situation where large electrical currents flow) which could cause damage to the homes wiring and fuse box. 

Have an electrician check your electrical outlets to see if there is an issue with the outlets or power strip. It may be, for instance that there are problems with the electrical wiring in the plug top which would be solved with a new plug.

5) Are extension leads ok to be used long term?

I think, without doubt, every customers’ home that we have visited has had at least one extension lead in use. These leads are meant normally as a temporary solution and not really meant for permanent use. Mostly, they are fine for low powered equipment and many of us use them for powering a television, tv box and perhaps a wi-fi router. The problems comes when a faulty extension lead is in use.

Extension leads are generally intended for short term use and should be considered safe for this purpose assuming that the rating of the extension cable is not exceeded.

It is possible and safe to use an extension lead for longer term use but care should be taken to ensure that no damage can come to the lead or strip of sockets from foot traffic or other hazards under its installed conditions. Where possible, avoid situating the leads on the floor where damage may occur and consider mounting them to the wall to prevent this. 

Seldom do homes have enough plug socket outlets for the equipment which we all possess and need to plug in and as such, the option is to either have lots more plug sockets installed or utilise an extension lead. 

If you are unsure of the safety of your appliances and extension lead set up then you should consult a professional electrician to establish any possible issues that may not be immediately obvious. 

6) How do you make extension leads safe?

Extension leads should be checked regularly for visual safety. No coloured cores of wires should be visible outside of the power strip or sockets area on the power cord. There should be no signs of discolouration or heat damage to the cable, socket outlets on the body of the lead or the plug top where the extension cord connects to the main plug socket in the wall. The wall socket should also be in good condition and not be discoloured or damaged. If the wall socket looks burnt then consult an electrician to investigate the cause and to replace the outlet.

The electrical cords that supply the extension lead and from there to appliances should also be checked to ensure they are not damaged. If you do find a damaged cord or other signs of damage to the device then the cords or device should be replaced immediately as this is a definite safety hazard. Replacement cords are not generally expensive and are relatively straightforward to install.

7) Can I plug a Kettle into an Extension Lead?

Actually, in most cases, YES. Shock horror but it's true. 

There are of course some provisos:

• The rating of the kettle must not exceed that of the extension lead
• The kettle must not be used for commercial purposes (continuous use)
• GREAT CARE must be taken to consider which other appliances will be plugged in to the extension lead so as not to overload
• If the lead is a reel type, then the instructions on unwinding must be followed

In general, plugging high-powered items such as kettles, into an extension lead is not a great idea and you should consider WHY the need has arisen to do so. Are the existing plug sockets in your home faulty? Insufficient number of outlets for the purpose of this? 

Instead of using extension leads long term which can lead to overloading the power strips and the socket outlets at the wall, it is often better to have further plug socket outlets installed. 

8) What should not be plugged into an extension cord?

In general, large appliances that draw a lot of electrical current and are very powerful should not be used in extension leads. 

Overloading these extension leads is actually very easy to do as well. If we had 4 plug sockets on a wall then it is much safer plugging in several appliances than if they were used in a 4-socket extension lead. It all depends, of course, on how much power the appliances draw, each appliance has an amperage rating or power rating.

There is a handy little overload calculator provided by electrical safety first which is linked on our website. Using this, you can work out what can be plugged in safely. Exceeding the safe rating of an extension lead can by a fire hazard. 

The safe rating of each extension lead should be contained somewhere on a sticker or data information section. This will allow you to compare the ratings of the appliances you wish to connect to the extension lead with the safe rating so that overload doesn’t happen. 

Overload is a situation where there is too much current demanded from an electrical circuit or device beyond the current flow or maximum current rating that was intended by the manufacturer of the device or designer of the electrical installation. 

9) Reel Extension Leads

There are other issues that can cause a faulty extension lead as well. Consider the longer variety with a reel. These reels are very handy as you can use them all the way down the garden or just coiled up a little bit with as much cable as you need unwound right? Wrong! 

These wind-up cable reels with lots of cable wound on them can be dangerous if care is not taken. Each of these reel extension leads will have some figures printed on them. These figures tell us how much power we can use or how much load we can plug in to the extension lead when it is fully wound and fully unwound. When an extension lead is fully wound it can handle far less power safely than if it were fully unwound. The reason for this is that cables heat up when lots of current flows through them and when an extension lead is not fully unwound it cannot expel the heat efficiently causing the cable to overheat and the pvc to melt. In other words, it can become a faulty extension lead!

Reel extension leads are very susceptible to physical damage, more so than a simple power trip type electrical device that sits behind the TV. Reel extension leads are more likely to show signs of wear quickly as they are generally outdoor extension cords used in harsh conditions. 

10) Can I use an extension lead outdoors? 

You can definitely use an extension lead outdoors but I would strongly recommend that the electrical circuit is protected by an RCD/GFCI (Electric shock prevention device) to minimise the risk of electric shock. 

No electrical equipment should be used in the rain for obvious reasons (I hope). 

Care should be taken not to use an appropriate extension cord outdoors. Certain cable types are more suited to this than others so read the instructions on your particular lead or reel to ensure that your intended use is ok for that particular device. 

11) Can I plug two extension leads into each other?

NO, generally not. There are of course exceptions to this but for our purposes in this article we are going with NO. 

There are a few reasons for this. 

• Excessive voltage drop
• Overload potential
• Overheating

The longer an electrical cable the more resistance there is and the higher the voltage drop will be. What is voltage drop? This is the difference in voltage between the end of the electrical circuit and the origin of the circuit (normally at your electrical panel).

Excessive voltage drop can occur with long runs of cable, large power-hungry electrical equipment and poor or faulty connections creating high resistances. This also leads to a tremendous amount of heat being generated and risk of fire.

If you are unsure about faulty extension cords, faulty extension leads, issue with power outlets or any aspect of Electrical Safety in your home then please contact us for a chat. We can often advise you from a photograph if you can send one.