Fishy Type Smell from Electric

1) Most of the time we pay absolutely no attention to the electrical wiring system in our homes.

The system will appear to function in a completely normal manner and as we go about our busy lives its easy to forget that this system, I actually doing anything at all. This is true of many things. Our cars will run without a service for a long time before they start to show problems, our boilers will also run and run until they break. 

This is the same for electrical wiring systems. They will take a lot of use and abuse over several decades without showing any signs of problems until something goes wrong. It is then that several larger issues can be uncovered. Years of neglect and lack of maintenance can then be seen when an electrician begins to investigate the electrical system and things can come to light that would otherwise have gone unseen. 

Occasionally though, there are signs. Signs that we should not ignore in our electrical system. One of these signs is a FISHY TYPE BURNING SMELL as this indicates that not only is there a problem but the problem has now become such that smouldering, fire, or melting has started to occur within the electrical system somewhere. Once this smell begins to appear in your home you should not wait to see what happens or put it off any longer, an electrician should be called immediately to investigate the cause of this and to see what repairs are now necessary. 

2) What causes this smell?

There are many reasons why this can occur. 

• Melted electrical accessories
• Melted wires
• Burnt out connections
• Loose wiring and overheating
• Overheated appliances and wires

Melted electrical accessories give off this smell as the plastic heats up and gives of toxic fumes. PVC around wires can give a similar smell when they overheat or burn also. 

3) What causes burnt out connections?

Typically burnt connections come from loose connections. Electrically speaking, a connection needs to be sufficiently tight to create a good electrical contact. Without this, appliances and electrical items will still appear to work but there is a high electrical resistance preventing electrical current from flowing freely. 

• This causes heat to build up. 
• This heat causes a higher resistance to occur.
• This causes even more heat.
• This then cases burning, melting and possibly fire. 

4) Why would wires become loose?

I’m glad you asked. Our electrical wires are made from metal, copper normally. When metal heats up and cools down it expands and contracts. The electrical accessories that we have in our homes such as sockets and switches have metal electrical terminals in them. These are made of different metal to the copper wiring which will also expand and contract. 

The problems comes when several things happen at once. Different metals will expand and contract at different rates which can cause wiring to become loose. 

We also have to consider the electrical supply frequency in the UK of 50Hz. We have an alternating power supply, that is, the electricity supplied cycles between a positive and negative cycle 50 times a second. This creates a very tiny vibration which can contribute to the problem. 

This expansion and contraction combined with the vibrations on the cables will eventually cause wiring to become loose in the sockets, switches and other electrical accessories in our home. 

There is then the action of turning things on and off, shower pull cords, socket switches, plugs being shoved in and out and so on. 

Why would wires become overheated?

There a few reasons why this might happen. 

• Poorly designed electrical systems.
• Wires unable to get rid of their heat.
• Wires to small for the load.
• Too many appliances turned on for too long.

When we design an electrical system, we have to consider what influences will affect the safe working of the electrical system, its environment and its users. We consider things such as contact between thermal insulation in lofts and walls and its contact with cables, the intended use of an electrical circuit, its cable size and circuit breaker size. The length of the cabling, other electrical cables installed close to each other and many more factors that may be an issue to the wiring system. 

When cables cannot get rid of their heat such as when they are covered in insulation in a loft for example, they can become overheated. This heat can travel down the cable and affect electrical accessories at the connections, the wires can melt inside and cause a fuse box / consumer unit to trip. 

When wires are too small for the load, or too much is asked of them they can overheat as the power being used on the electrical circuit is too much for the cable to cope with. Normally a circuit breaker / trip switch would monitor the loads and trip if there was a problem but if the cable is too small then this will not happen. 

A FISHY TYPE BURNING SMELL is not to be ignored. This smell is indicative of problems within the electrical system and should be found as soon as possible. Replacing an electrical accessory is not nearly as expensive as rewiring a house or dealing with a possible house fire. 

5) How do I know if my electrics are safe?

The best way to determine the safety of your electrical installation is to have a professional come and carry out an electrical safety check for you. We have written blogs and help sheets about this for your information. 

There are only a few occasions when we can visually inspect your electrical installation and determine its condition. The most accurate way to discern the condition of your electrical installation if through thorough inspection and testing. 

If you have any questions then please use our contact form to get in touch. We will answer you query quickly and as in depth as possible. We are always happy to help.