Protecting your equipment

Electricity supply can be interrupted for a number of reasons, some of which are planned (e.g. where the network company needs to perform maintenance on its lines), and others unplanned (e.g. as a result of storm damage or a car hitting a power pole).

Where possible, Contact, or the network operator, will try to let you know in advance of any planned interruption to your energy supply.

However, we may be unable to give advance notice in relation to sudden or unplanned interruptions, or for power fluctuations; such as electrical surges or spikes, brownouts, and blackouts.

Electricity surges (or "spikes") are momentary fluctuations in supply voltage.

They can be caused by a number of events; including lightning strikes, trees touching or falling on power lines, or large-scale electrical users switching equipment on and off. Turning on and off smaller electrical equipment can also cause small "localised" electrical surges. When some electrical appliances start up, they can draw a brief burst of additional power that causes the voltage within the household or business to briefly fluctuate. During this start up, other appliances on the same circuit effectively get "short-changed" while the starting appliance gets the power it needs to turn on.

Surges are generally considered to be the most common and destructive of all the types of power disturbances and can affect power supply to whole neighbourhoods, your street or just your property. Even small surges can cause damage to sensitive appliances.

A brownout (or "sag") is a drop in your electrical supply voltage. The term "brownout" comes from the dimming experienced by lighting when your supply voltage drops (or sags).

Brownouts can occur within a street or suburb when there is a partial failure of network equipment such as "distribution substations". This can result in electricity being supplied to households or businesses at (for example) less than 150 volts instead of the usual approximately 230 volts. Lights will be noticeably dimmer and some appliances may not work until the usual voltage is restored.

Regular brownouts can reduce the efficiency and life span of your appliances.

A blackout (or "outage") is a total loss of supply of electricity to your property.

Blackouts are commonly caused by lightning, storms, ice/snow on power lines or vehicles hitting power poles. They are also sometimes the result of natural catastrophes, vandalism, equipment failures, excessive demand on the electricity network or other events.

Blackouts may last from a few minutes to several weeks depending on their cause.

A blackout may cause damage to electrical equipment if there is also a surge or spike at the time the supply fails or when it is restored.

To minimise the possibility of damage being caused to your appliances and equipment by electrical interruptions, such as electrical surges and brownouts or blackouts, it is recommended you consider installing surge protection or power conditioning, particularly for:

• Computers and laptops
• Stereos
• TVs, DVD and video equipment
• Washing machines, dryers and dishwashers
• Heat pumps

During brownouts or blackouts, it is recommended that you switch off all electrical appliances at the wall outlet, to prevent potential damage from operating at reduced voltage or from an electricity surge when your supply is restored. Some lighting should be left switched on to alert you when the supply is restored.

There are four main kinds of protection devices you can also use to protect your appliances, and yourself:

• Surge protectors
• Power conditioners
• Uninterruptible Power Supply (UPS)
• Residual Current Devices (RCDs) and Isolating Transformers

We recommend you contact your local electrician or visit your local electrical retailer to get advice on the right protection suitable for your needs.

A surge protector (or surge suppressor or surge filter) is a common appliance designed to protect electrical devices from power surges and your first line of defence against power fluctuations. A surge protector regulates the voltage supplied to an appliance by either blocking or grounding voltages above a safe threshold.

A power conditioner (or line conditioner) provides a higher level of protection by regulating the AC power supplied to an appliance and is typically used to protect computers from surges and brownouts.

An Uninterruptible Power Supply (or UPS) is an electrical device that provides emergency power when your main power source fails. A UPS differs from an auxiliary or standby power supply by providing instantaneous or near-instantaneous protection from input power interruptions usually by means of batteries for low power users, or diesel generators for high power users.

Residual Current Devices (RCDs) and Isolating Transformers protect you against injury from electric shock as opposed to protecting your appliances from supply interruptions.

It is recommended you seek advice from a registered electrician if you wish to install RCDs in your property. It is also recommended you always use an RCD (or an isolating transformer) when using portable electrical appliances such as power tools or other outdoor equipment.

We recommend you check your insurance policies to see whether you are covered for loss suffered due to failure, interruptions or fluctuations in your electricity supply.

Talk with your insurance company or agent if you need further help.

Where can I go to get more information or to buy electrical protection devices?

We recommend you contact your local electrician or visit your local electrical retailer to get advice on the right protection suitable for your needs.

What do I do in an electrical accident?

• Don't touch the injured person if they're still in contact with a live electrical source.
• Switch the source of electricity off, or if you can't, move the source away from you and the injured person using a non-conducting object like a wooden broom handle. Then call an ambulance immediately by dialling 111.

What should I do if my electricity supply is interrupted?

• First check to see if neighbours have power – if they do not it is likely that there is a power cut to your area.
• Please report any problems with your electricity supply by calling our faults number as soon as possible. We will report your fault to your local network operator.
• If your property is in a remote or rural area, call our faults number to log the fault.
• Make sure you turn off appliances at the wall. Heaters and stoves can be a fire hazard, and some appliances might be damaged when the power comes back on. Your electrical appliances and equipment could be adversely affected by both electrical surges and brownouts when the power is restored.

What if my premises is the only one without power?

• If your power goes off suddenly and your neighbours' lights are still on, a circuit breaker or fuse may have tripped in your fuse box or meter board.
• Check your fuse box or meter board to see if a circuit breaker has tripped or a fuse has failed. If you are unsure of how to do this safely, call an electrician for advice or assistance.
• If your circuit breakers and fuses appear normal, you may have a fault in the supply to your premises.
• Call our faults number if you have a gas or electricity supply problem.