For example, most people know not to plug an extension lead into another extension lead but why is this? The majority of extension leads are rated at a maximum of 3000W and 13A (however some can be 10A or less). Therefore, doubling up on extension leads means your chances of exceeding the maximum load are significantly increased.


Which appliances are most likely to overload a socket?


Most people would be unlikely to know what an amp is, let alone how many watts their microwave uses. As an electrician, knowing which appliances are likely to use a lot of power can help you identify whether a customer is at risk. There are certain appliances you can look out for when you’re at a customer’s house. Kettles are one of these as they are right on the limit for both amps and watts and so should never be plugged into an extension lead with other appliances, as this is a sure-fire way of overloading the socket. Most white goods, toasters and electric radiators are also appliances to be wary of.


Block adaptors or multi-way bar extension leads?


Block adaptors are often preferable because they don’t have a lead that gets in the way. However despite being built to a high standard to generally be used safely, we recommend as a general rule to steer clear of block adaptors as the vast majority do not have a fuse which increases the risk of fire.


So what’s the best solution?


Installing more plug sockets is by far the best long term solution and would be a sensible recommendation, however this isn’t always a viable option. Avoiding extension leads altogether would also work but this can be difficult as there are so many small appliances with short power cables, such as lamps and radios. Having said that, extension leads that are over 15 metres long should never be used and cable drums should also be avoided due to overheating.


Getting a feel for the sort of appliances that pose danger is the best way to help keep customers safe. If it’s not possible to install more sockets, then suggesting multi-way bar extension leads with cables less than 15m long is the next best thing. At the end of the day, safety is of upmost importance and helping customers understand the risks involved in certain appliances is sometimes the only thing we can do. Below is a calculator that shows the combinations of appliances which are safe, to help you prove your point to customers.