* Con Ed reduces voltage in NY's Brooklyn, Bronx * Company, union still far apart in talks-union * Heat wave to bake New York through weekend By Scott DiSavino NEW YORK, July 6 (Reuters) - Contract talks between Consolidated Edison Inc and locked-out union workers resumed Friday morning while replacement crews struggled to end brownouts in Brooklyn and the Bronx as New York City sweltered in a prolonged heat wave. The company and the union negotiated for about 10 hours on Thursday without reaching a deal. They started again at about 9 a.m. Eastern Time Friday and were currently taking a lunch break, a union spokesman said. Despite the ongoing talks, John Melia, the spokesman for the Utility Workers Union of America Local 1-2, representing 8,500 Con Edison union workers locked out by the company on July 1, said the two sides were still far apart. "Nothing has changed. Things are still grim," Melia told Reuters. In addition to health care costs and wages, one of the major sticking points is the company's insistence that defined benefit pensions be changed to a 401(k) type of retirement savings account. A spokeswoman at Con Edison, Sara Banda, said it was too early to say how the talks were going since they were still ongoing. Neither side could say whether the talks would continue over the weekend. "We won't know whether the talks will continue over the weekend until later today," Melia said. Meanwhile, a heat wave continued to bake the Big Apple for a third day in a row and replacement crews made up mostly of Con Edison managers sweated in the heat as New Yorkers cranked up their air conditioners, straining parts of the grid. Temperatures in New York were expected to reach as high as 92 Fahrenheit (33 Celsius) on Friday, 98 F on Saturday and 90 F on Sunday before returning to more normal levels in the mid-80s next week, according to AccuWeather.com. On Wednesday, Con Edison reduced voltage by 5 percent in several Brooklyn neighborhoods to protect the overall system and maintain service as crews fixed lines feeding power to the communities. On Thursday, the company reduced voltage in additional Brooklyn neighborhoods and in some Bronx neighborhoods. The company said the replacement crews had made some repairs but were still working on feeder cables in the affected neighborhoods. The voltage reductions remained in place Friday afternoon. Air conditioning doesn't lose power in a voltage reduction, but incandescent lights, hot water heaters and some motors are slightly affected. The reductions were the first since the company locked out the union workers after contract talks broke down. Con Edison said the voltage reductions were unrelated to the lockout, noting the company had reduced the voltage in parts of Brooklyn and Queens during a heat wave before the lockout in June. But the union said the voltage reductions were a sign that Con Edison could not keep the system running without the union workers. "If something goes wrong, Con Edison will not be able to respond in a timely manner, endangering all New Yorkers," the union's Melia said. WORKERS INJURED The union has claimed the replacement workers were suffering injuries due to their inexperience. Four replacement workers have been injured since the lockout began but none of the injuries was life threatening, according to Con Edison. One worker suffered second-degree burns on his face, another had a suspected heart attack while off duty, a third had minor burns on his hand, and the fourth suffered partial hearing loss after an air horn was blasted in his ear. The company said many managers in the field came up from the union ranks and were experienced in fixing the cables to keep the system running. So far, voltage reductions were relatively minor, and only 134 customers were without power Friday afternoon -- out of the 3.2 million homes and businesses Con Edison serves in New York City and Westchester County. The company asked all customers to conserve power during the heat wave but has not told customers in the affected Brooklyn and Bronx neighborhoods to turn off their air conditioners.