An electrician was employed by an electrical contractor engaged by the network operator to carry out work on their Advanced Metering Infrastructure (AMI) Project. The electrician was carrying out the replacement of an analogue kWh meter with a new digital kWh meter at a domestic property in Esperance.
After installing the new meter, the electrician replaced the SPD to reconnect the supply electricity to the installation, marked the kWh meter terminals as correct and carried out a load test to ensure the new kWh meter operated correctly before reconnecting the installation to the electricity supply.
Later that day, a Horizon Power Inspector was called to the site to investigate a reported electric shock received by a resident at the property.
Prior to receiving the electric shock, the resident had experienced electricity supply problems to appliances in the home and had gone to check the kWh meter enclosure and main switchboard to investigate the cause. Upon contact with the conductive kWh meter enclosure lid, the customer received an electric shock to her right hand.
Upon inspection, the Horizon Power Inspector identified the customer load neutral conductor of the electrical installation had not been connected at the kWh meter and had been left unterminated behind the kWh meter panel (see photograph below).
As a result, neutral current flowed via the installation’s earthing system, causing the electric shock to occur.
In addition, when the load neutral conductor is not terminated for a three–phase supply installation, the single-phase supply voltage floats from 0 to 400 V ac. This results in over or under line voltage, which caused the electricity supply problems to the resident’s appliances. Potentially, this could have damaged the electrical appliances or a caused a fire.
The electrician (himself) did not receive an electric shock while closing the kWh meter enclosure lid as he was wearing rubber soled safety footwear.
Building and Energy’s investigation revealed the main contributing factor for the incident was the electrician failing to carry out an inspection of the completed work to ensure the correct circuit connections had been made as per Clause 8.2 of the AS/NZS 3000: 2007 “Wiring Rules”.
The electrician pleaded guilty and was convicted and fined $10,000 with court costs of $744.35 in Esperance Magistrate’s Court.