Energy Safe Victoria issues flood warning

Residents returning to their flood-ravaged properties should take great care before using anything electrical, Energy Safe Victoria (ESV) - the state’s electricity regulator - warned recently.

ESV warns that where properties have been significantly damaged by floods, it is imperative that checks of wiring and other electrical installations are made before power is restored to the property. Before appliances are connected and turned on, these must be checked to ensure water has not entered the appliance making it unsafe to use. Such checks of the installation wiring must be carried out by a licensed electrician or licensed electrical inspector. Checking of appliances can be carried out by a licensed electrician, licensed electrical inspector or an appliance repair specialist.

Building occupants are urged not to use any water-damaged electrical appliances until they have been checked for safety, warning that they may not work safely once they have dried out. A special caution has been issued concerning electricity-fired gas central heating systems, because floodwaters could have damaged electrical wiring and control systems, as well as the gas burners, flue ways and pilot lights.

lf supplies have not been restored to homes for any reason, householders must not connect generators or perform other electrical work around the home. Such practice is both illegal and dangerous - such work can only be carried out by licensed electricians. Households still without power after electricity supplies have been restored to their neighbourhood should seek the help of their network provider. The problem could be a fault in the supply line to the property or a fault within the property's electrical installation. lf there are continuing power supply problems within properties, an electrician licensed by Energy Safe Victoria must be engaged to perform any electrical repair work.

Guidelines for electrical contractors

ESV has also provided guidelines for electricians and registered electrical contractors who have been engaged to perform electrical inspections and/or repair works to properties affected by floodwaters to ensure these activities are performed in a safe manner. Potential risks include poor insulation resistance, earth leakage and short-circuits.

ESV requires a safe approach to all such works including:

• A check of testing equipment to ensure it is functioning correctly;
• Ensuring appropriate safety apparel is being worn and the work environment is suitable to perform the work safely;
• A test to prove any exposed conductive parts and parts that would be live in-service 'de-energised';
• A check for isolation of supply (distributors);
• A check for isolation of supply (alternate, eg, generator/solar); and
• A re-check of testing equipment to ensure it is still functioning correctly prior to touching parts of the installation.

A visual inspection must be carried out before or in association with mandatory testing before the electrical installation is ready to be placed in service, including general condition of the electrical equipment, eg, signs of damage that could impair safe operation, signs of ingress of water to electrical equipment.

Where water has entered electrical equipment, these parts should be replaced or disconnected prior to re-energisation of the electrical installation.

The following mandatory tests in accordance with AS/NZS 3000:2007 Amt 1 shall be carried out on low-voltage electrical installations prior to them being placed in service:

• Continuity of earthing system (earth resistance of the main, protective earthing and bonding conductors);
• Insulation resistance (of all fixed wiring and appliances to be connected);
• Polarity;
• Correct circuit connections;
• Verification of impedance required for automatic disconnection of supply (earth fault-loop impedance); and
• Operation of RCDs (if supply is available).

In circumstances where the distribution company has isolated supply to the individual installation, a Certificate of Electrical Safety is required to be completed certifying the electrical installation is safe to be reconnected to supply by the distribution company. In circumstances where the installation has undergone any associated repairs, a Certificate of Electrical Safety is required to be completed. Upon application, ESV will issue replacement Certificate(s) of Electrical Safety to Electricians and Registered Electrical Contractors where they have performed electrical repair work to premises affected by floodwater, for no profit or gain.