Rural residents are warned they may be left without power as electricity workers walk off the job in a lengthy dispute over pay and conditions.
More than 2000 Essential Energy workers begin a series of rolling 72-hour work stoppages from Tuesday, saying pay negotiations have stalled.
The NSW government-owned company operates one of Australia's largest electricity networks, covering rural and remote parts of the state and southern Queensland.
Electrical Trades Union secretary Allen Hicks said NSW Energy Minister Penny Sharpe on Monday indicated the government would not move on five key issues.
The union is calling for a pay rise on par with colleagues in Queensland and Victoria, family recovery leave for workers who spend as much as half the year away from home, as well as compensation for working in the rain.
"The NSW government has made it very clear that we're in for a tough summer when it comes to strain on our electricity grid and the workers who manage it - the government needs to make sure we're equipped to deal with what is ahead," Mr Hicks said in a statement.
"We've given the NSW government an opportunity to avert this action, but for reasons no one can understand, they've decided to force our essential power workers to this point."
Crews will continue to respond to emergencies and life-threatening events during the strike, but residents and businesses could be left to endure blackouts.
The network services 890,000 homes and businesses across 95 per cent of NSW.
Essential Energy said it had worked constructively to progress an enterprise agreement, including through 19 bargaining meetings since May.
But the union has not shifted its position nor made counter offers to come to an agreement, the company said in a statement.
The various pay and negotiation claims total $275 million, which would be passed onto consumers already facing cost-of-living pressures, it said.
The industrial action was "disappointing" and threatened reliable power supply, according to the company.
"It is also delaying progress on residential, commercial and energy generation projects," it said.
"Our regional communities have been negatively impacted by industrial action since August 2024."
