Outage events

Intermittent faults affected power supply across Darwin suburbs earlier today.

An outage at 11.30am, caused by a node failure on a switchboard at Channel Island, affected customers in areas including Berrimah, Bakewell, Roseberry, Northlakes and Marlows Lagoon. This outage meant that two of the seven generators at Channel Island were not able to be used while the fault location was being determined and isolated.

Power and Water crews worked to isolate the faults and return power to customers as a matter of priority.

Supply was progressively returned to customers and complete restoration was secured at 1.15pm. A second outage occurred when a generator at Berrimah failed to start due to a bus bar fault, affecting some Northern suburbs residents for 30 minutes mid-afternoon.

Power and Water General Manager Networks Bertram Birk said these incidents highlighted the importance of the Corporation’s Power Networks works program – which includes an investment of almost $70 million in 2007-2008 to ensure infrastructure is best able to serve the needs of Territorians.

Much of this investment is focused on works undertaken over the dry season, when the demand for electricity throughout the Territory is much lower. This means that Power and Water has a window of opportunity to isolate key infrastructure to ensure it is properly maintained and prepared for the incoming wet season.

In addition, the Corporation is in the process of completing two major infrastructure development projects valued at more than $100 million in Darwin which will help meet increasing demand as a result of significant population growth in the Darwin region.

The new Weddell Power Station is expected to be operational before the incoming wet season, and the Frances Bay Substation will be online in January 2008.

"In addition to our increased investment in our works program the Weddell Power Station and Frances Bay substation will further enhance our system and help with diversifying our supply for our customers," Mr Birk said.

”Within our works program, alongside routine inspections, tree cutting and repairs, specific maintenance programs have been planned for and undertaken over the dry season.”

These programs include:

1. Helicopter aerial inspections and repair of the 132kv and some 66kv transmission lines;
2. Shut down repair on Snell Street substation including substation transformer 2 and City Zone substation transformer 2.
3. Preventative replacement of pneumatic seals on the 132kV CB’s.
4. Scheduled diving inspection of the 66kV submarine cable
5. Mid life service of the 132kV Gas Insulated Switchgear in May 2008
6. Substations earthing audit and repairs
7. Scheduled power transformer OLTC maintenance

There has also been a significant investment in the annual asset upgrade and replacement program.

Initiatives under this program have so far included:

1. Substation battery replacement and charger upgrade
2. Feeder insulator replacement in both the Darwin and Katherine areas
3. Installation of air conditioning units in Zone substations in Katherine and Darwin
4. Upgrade of standby genset at Hudson Creek
5. City Zone substation building repairs
6. Retrofit of 11Kv oil circuit breakers

The major asset replacement and upgrade program for 2007/2008 includes:

• Installation of transformer bundings at various substations
• Installation of cathartic protection on 132kV towers over the CIPS channel
• Replacement of the  66kV insulators on Arnhem Highway
• Replacement of 66kV and 22Kv CB’s at McMinns Substation
• Replace Voice International 66kV circuit breaker

Contact:
Tracie McPherson,
Media Manager,
Corporate Communications
0401 117 599 or 8985 8481