Short Power Cuts and Voltage Dips
We want you to have a safe and reliable electricity supply, but temporary interference can occur particularly in rural areas supplied by overhead lines. Lightning, birds, small animals or trees can at times cause temporary faults otherwise known as short power cuts.
Why do we get short power cuts?
If our recloser (automatic switch) detects a problem on the overhead line network it will disconnect the supply to prevent permanent damage.
Why do they last only a few seconds?
The switch opens and closes several times in quick succession to see if the fault has cleared. The switch will put the power back on almost immediately if the problem has disappeared. However, if the cause of the fault remains the recloser will leave the power off until our field staff can determine the cause on site.
What are the advantages of the recloser (automatic switch)?
The power will return quickly if the problem is temporary and as they are automatic there is no waiting for somebody to reset them. Automatic switches prevent long power cuts and, because of their speed, can prevent serious damage to our equipment.
You may have been affected by a dip in the supply voltage for instance if you have noticed your lights dim briefly or had to reset a clock or video.
What causes dips?
From a main substation there are several cables and overhead lines supplying an area. These circuits (or feeders) often interconnect with each other so that if a fault occurs on one feeder we can often restore electricity from another. If this happens there may be a momentary voltage dip.
Are dips bad?
The voltage delivered to your home varies all the time. And variations such as we've described above are part of the normal operation of an electricity distribution system. Manufacturers of electrical equipment sold in the UK design their products to cope with these variations.