Intermittent Electricity Power Outage 7 Common Causes

1) Intermittent Power Outage Problems

There are several reasons why you might be suffering intermittent power outage problems. These may be electrical issues internal to your home, with the supply from the power plant or local transformer or even with the underground power lines buried in the ground between your home and the power plant. The 7 most common causes are:

• Linked Main Switch Failure like the photo
• Main Fuse/Supply Equipment Connection Problems
• Burnt Out Connection in Electrical Panel or Consumer Unit
• Loose Connections in the Street
• Local Works on the Power Supply
• Electric Meter or Connections Failing 
• Issues with External Isolator

2) Linked Main Swich Failure

The linked main switch is the device which turns off the power supply to the electrical panel or in some cases, the whole of the electrical installation in your home. There is occasionally an external linked main switch that sits outside of the electrical panel which is the best type for convenience. Where there isn’t an external linked main switch, this device should be inside the electrical panel. It can look like one of the following:

       
This device has to handle all the electricity that flows through it to power your home. These devices should be adequate to carry the load or if not, they will burn out and cause an INTERMITTENT POWER OUTAGE and eventual complete power loss. 

These Main Switches can fail in several ways:

• Internal Failure through high resistance
• Internal Corrosion and Rust
• Loose connections at the top or bottom causing burn out
• Excessive Load causing Failure

3) Main Fuse/Supply Equipment Connection Problems

The Main Fuse is responsible for protecting the electricity suppliers incoming power cable. Without the Main Fuse it would be possible to overload the supply cable causing failure, fire, and possible problems for the neighbourhood if the supply network equipment became damaged. 

The supply main fuse and intake equipment looks like this:

There is a 100 amp fuse installed in this particular ‘supply cut out’ (intake equipment), or at least, that is what is indicated on the outside. If 100 amps is likely to be exceeded then the fuse will get very hot and will eventually blow to protect the supply cable. 

These ‘supply cut out’ devices are often black or grey and appear to be made of a plastic. This equipment should not be touched by anyone other than the Distribution Network Operator who are the agency responsible for the power supply entering your home from the street and beyond to the power station. 

There are connections inside this box which can occasionally fail. If there is an INTERMITTENT POWER OUTAGE then this box could be the culprit. 

Solution

If there is smoke, burning smells or crackling going on inside or near this box then you should call 105 (freephone) immediately (UK). This will put you in contact your local agency that can assist you with any issues relating to this box or the cable supplying it. 

4) Burnt Out Connections in Electrical Panel or Consumer Unit

When there are failing or burnt-out connections inside the electrical panel or consumer unit, there may be no external signs that this is happening. If the panel or unit appears to have scorch or burn marks, appears melted or disfigured then this could indicate that there are serious electrical issues inside the box. 

Internally to the box there are several points that can overheat and burn out causing fires, power failure and funny smells. Over time, electrical connections can work loose due to heating and cooling, expansion and contraction, and vibrations on the cables and terminals. Without regular maintenance from an experienced electrician, the panel is likely to fail in time. 

Solution

Contact an electrician to come and investigate the issues in your electrical panel. This is important as there are many live and dangerous parts inside a consumer unit or electrical panel and without the right equipment, tools, and knowledge it is dangerous to investigate.

To learn more about what is inside a consumer unit check our article showing all the components and their purpose.

5) Loose Connections in the Street

Just as with loose connections inside your electrical equipment in your home, there can be loose connections and electrical joints outside in the street. These can be buried underground making tracing the issue difficult or costly. When electrical connections fail in the street, dangerous electrical situations can occur within your home leading to electric shock or injury. If you find that you are receiving shocks from equipment, have no power yet are receiving shocks or find that you are suffering momentary outages, then there is a likelihood that there may be issues in the outside electrical supply from the street. 

Solution

Check with your neighbours to see if they are experiencing similar issues as there are often several houses that are supplied with the same street power cable and your neighbours may experience similar electrical symptoms to yourself. 
If your neighbours have no issues then contact an electrician immediately to investigate without delay. If your neighbours are having the same problems then contact 105 (UK) and they should be able to assist you. 

6) Local Works on the Power Supply

When the electricity company are carrying out unplanned works on the electrical supply then you may not necessarily know about it. These unplanned works are often due to failed transformers, electrical issues in the street or power cuts that have occurred in other areas. Sometimes a power cut in another area will also affect you when they turn off the supply to work on the issue. 

Solution

Check with your neighbours to see if they have received a leaflet or other information regarding the issue. Ask if they are having similar problems as, if they are, then the issue is not likely to be inside your home and is a supply problem. 

If you have no luck then contact 105 (UK) freephone and ask if there are any planned or unplanned works being carried out in your area, explain that you are having INTERMITTENT POWER OUTAGE and they should be able to assist you.

7) Electric Meter or Connections Failing

The electric meter is the box that monitors how much electricity you are using and have used. It is responsible for recording this information and in some cases, reporting the usage statistics to the electricity supplier for billing and information gathering purposes. 

When this equipment begins to malfunction, there may be overheating, burning smells and occasional power loss. Flickering lights are also a common sign that there may be power supply issues such as loose or failing electrical connections. 

Check to see if your meter has the normal lights illuminated. Some meters have a red or other coloured light to indicate that there is power to the meter. Without this light, there is likely a supply issue (or your meter doesn’t have a light in the first place) to your meter.

Solution

Visually inspect the electric meter for signs of discolouration, melting or strange smells. Do not touch the electrical cables in case they are loose as they may fall out. 

If you believe that your electric meter is not providing power to your home electrical installation then contact your electricity supply company that you pay your bills to. This equipment is looked after and provided by the company that you pay each month for your supply. 

8) Issues with External Isolator

If you have a standalone external electricity isolator then this could be faulty. This device is designed to shut off the power supply to each and every consumer unit or electrical breaker panel that you have in your home. They occasionally burn out and as they begin to fail, they may start to cause power interruptions or INTERMITTENT POWER OUTAGE.

This device is normally situated after the electricity meter and before the first electrical panel or consumer unit. It is often a linked main switch type device as described above. The device usually has two thick power cables going in and then back out. The cables should come from the electricity meter and then leave the isolator heading to the consumer unit(s). 

Solution

IF you suspect that this device is faulty then contact a professional electrician for advice. Touching or interfering with the device could lead to electric shock, fire or burns. 

9) What do these problems cost to fix?

If there are problems with the supply cut out / main fuse then this is generally the responsibility of the DNO (Distribution Network Operator) and will usually also be at their cost unless there is evidence of tampering or interference. If the issues are before this equipment, such as in the street, then it is likely that the cost will also be the responsibility of the DNO. 

If the issues are with the electricity meter, then this is generally the responsibility of the electricity supply company (where you pay your bills) and the cost for repairs is likely to fall to them. 

If the issues are with the electricity supply isolator, the electrical panel, consumer unit, main breaker or in your whole house home wiring system then these costs are likely to be your responsibility or that of your landlord. 

There are exceptions to this of course and you should check with each agency or company who is going to cover the cost of any repairs and what those are likely to be. 

10) Is there anything else I should check?

If you have surge protectors in your consumer unit or electrical panel then you should check these regularly to see if they are damaged. Power surges can eventually render these devices ineffective so ensure that the indicators on the devices are showing that they are still working. 

If these devices are showing that they are no longer protecting your installation then have an electrician come and check / replace them for you. 

11) What about a Partial Power Outage?

If you experience a partial power outage then it is most likely that the issue is with your homes electric system and not necessarily an outside factor. Try resetting the Main Breaker, GFCI or RCD device if it has tripped. 

The RCD device can look like the following:

There is normally a test button on the RCD or GFCI. If the switch is down then it indicates that the device has tripped. The reasons for this could be faulty wiring, damaged electronic devices, faulty appliances or issues with plug socket outlets and switches. 

No matter where the issue lies that is causing power problems, there are a few things you can try when a device like this trips. Try unplugging all your equipment and resetting the device. If this doesn’t work, check out our article on this subject.

12) WHAT IF NOTHING HAS TRIPPED?

If there are no switches down in the breaker box but you have no plug sockets working, loss of power to lights or a problem area of power in the home, then there a number of possibilities that could lead to this issue occurring:

• Damaged Circuit Breaker
• Poor Connection on Sockets
• Loose Wiring in a Junction
• Burnt Out Wiring

An electrician may be needed to establish where the problem lies in the electrical system. Any work carried out with wiring, electrical accessories, around or in the fuse box / electrical panel is likely to involve live parts and electrical danger. 

13) Summary

In the event of a power outage, ask yourself if this has happened before and if it is a common occurrence? An intermittent outage is often simply a blip in the supply and is nothing to worry about. A brief outage can occur if power stations need to carry out maintenance, works need to be carried out on the electricity network, inclement weather is present in the area or a temporary short circuit occurs.

If brief power outages occur frequently then there may be serious issues with your electrical system and you should contact an electrician to investigate.