Loadshedding and your electrical appliances

The differences between a power outage and a power surge are important not solely based on the steps you take, but also in terms of how they affect appliances.

A power outage refers to a sudden and complete loss of electricity due to an interruption in your incoming power supply. Typically, this would be a power failure when, for example, the electrical substation serving your neighbourhood is tripped off. It would also refer to a scheduled loadshedding event when the power supply to a whole town is cut off by Eskom.

A power surge refers to a short but intense spike in the incoming electrical current. It may last only a few nanoseconds but may shoot the incoming voltage above the safe limit for your appliances. This surge can happen when, for instance, there is a lightning strike which hits an incoming power line and discharges millions of volts into the line. The more common occurrence, however, is when power is restored after a blackout and there is a short, sharp surge in the voltage before the system returns to the steady state design current. A surge may also be caused when a big electricity consumption unit such as an air-conditioner is turned on.

For household appliances such as a ceiling fan, the implications for the above events are:

• A power outage is very unlikely to be damaging to your appliance/fan but it may result in the loss of data or “system memory” in cases where the device is controlled by pc board/semiconductor circuitry. This may mean that you will need to “re-program” settings such as a fan remote control pairing. But thankfully, no permanent damage will generally have been caused to hardware.

• A power surge on the other hand, may spike the voltage beyond the tolerance level of your appliance and may blow a fuse or melt or erode the circuitry, effectively destroying it. This may mean that a complete replacement of either the motor or the fan receiver/controller may be necessary.

• As far as Loadshedding is concerned you will appreciate then, that it is much more important to take protective measures for when the power comes back ON, rather than when the power goes OFF.

1. If you know that loadshedding is going to occur at a certain time, then disconnect the appliances BEFORE the time and keep them OFF until a few minutes AFTER the power has been restored. If the item is plugged into the wall, then it is wise to unplug the item from the wall socket. In this way, there is no chance of a voltage surge. It may be an idea to keep just one light switch on in the house to let you know when the power has been restored!
2. When installing a ceiling fan, make sure that the fan has its own isolator switch that is not part of a larger electrical circuit serving other fans or appliances. This means the fan can be independently powered OFF during a thunderstorm for example or prior to scheduled loadshedding. It will also mean that it will not be affected by power surges or dips brought about by other appliances on the same circuit.
3. Invest in a surge protector. There is a vast array of surge protectors from relatively cheap, single-appliance units, to sophisticated and expensive whole-house systems that are installed at the main distribution board. Consult an electrician and establish what your appliances at risk are, before making a decision.
4. If you have the budget, you could consider a UPS (Uninterrupted Power Supply) system for your more expensive appliances or electronic components. Typically, these are intended more for power outages where data loss or data corruption could occur, but many UPS systems also provide for surge protection. Once again, consult a specialist supplier for detailed specifications.
5. Check your home insurance policies. Although this is not strictly speaking a protective measure, it may protect you financially. Make sure that your policies cover damage or loss due to power outage and, more specifically, power surge. Speak to your broker for advice and an estimate of cost.