Understanding outages and voltage dips

Understand the difference between outages and voltage dips. Learn which electrical installations customers are responsible for.


A power outage occurs when there is an interruption to the power supply. These interruptions are often temporary.


We strive to provide reliable and safe electricity all the time. However, outages may occur due to unavoidable factors such as:  

  • Adverse weather
  • Third-party damage
  • Equipment failure 

Preparing for and dealing with outages

Learn how to prepare for power outages, and what to do in the event of a power outage (e.g. due to severe weather).


A voltage dip occurs when the supply voltage drops below 90% of the standard voltage. Most voltage dips last for around 0.1 sec.


During a voltage dip, the power supply is not interrupted. However, customers may experience some impacts. For example: 

  • Customers' lights may dim or flicker;
  • Customers' lift may trip;
  • Sensitive equipment may be affected.


No power system can entirely avoid voltage dips. There are various factors to trigger a voltage dip:

  • Adverse weather conditions
  • Vegetation, animal, etc. 
  • Equipment failure 
  • Third party damage
  • Cable damage due to excavation

Protecting customers' equipment

Customers should turn off their heavy loading appliances (e.g. air conditioner) when a voltage dip leads to power interruption. For more information, please:

CLP’s responsibilities 

We are responsible for: 

  • Generation equipment
  • Overhead lines
  • Underground cables
  • Substations/Transformers 

Customers' responsibilities 

As a CLP user, customers are responsible for:

  • The main switch and other switchgears in switching rooms
  • Rising mains and switchgears in buildings
  • Meter rooms on individual floors
  • Switch boxes and circuit breakers
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