Sydneysiders in the CBD have faced power outages during peak hour traffic on Thursday morning.
The blackout at Wynyard and Barangaroo initially impacted 959 customers, Ausgrid said.
However, crews have worked to minimise the issue, which is now effecting 73 people.
Know the news with the 7NEWS app: Download today
The train stations were also affected.
The chaos began about 4.55am on Thursday, with the outage said to be “unplanned”.
Traffic lights at the York and Market St intersection also went out due to the outage, The Daily Telegraph reported, however have since been restored after crews installed a generator.
NSW Energy Minister Penny Sharpe said the CBD’s power substation had flooded on Thursday morning, resulting in the outage.
The outage comes after NSW residents sweltered through a heatwave on Wednesday, with concerns about energy usage across NSW.
Residents were urged to go easy on air-conditioning and turn off lights and appliances during the heatwave.
Sydney’s city centre recorded a peak temperature of nearly 33C late on Wednesday morning, while by early afternoon the mercury had risen to nearly 39C across a swathe of suburbs from the southwest to northwest.
Western Sydney peak temperature forecasts were more than 10C above November average maximums, weather bureau senior meteorologist Miriam Bradbury said.
“While anomalously high, these temperatures are not expected to break any records (but) it’s more the duration of the warm conditions, including those warm nights, that is more significant,” she said.
Rain is predicted to hit eastern NSW on Thursday.
– With AAP