LONDON, June 24 (Reuters) - Play was suspended briefly on all courts at the Wimbledon qualifying tournament on Wednesday because of a power problem with the automated line calling system.
Britain's Dan Evans had just lost the first set of his match against Australian Tristan Schoolkate on a baking hot day at Roehampton when the problem arose.
Play eventually resumed after a delay of around an hour.
"There was a temporary loss of power to part of our Qualifying venue, which meant that the electronic
line calling system could not function," an All England Club spokesperson said. "Power has now been restored and play is expected to resume shortly."
An extreme heat warning was issued on Wednesday for parts of Britain, including London, with temperatures predicted to reach the high 30s Celsius in the afternoon.
It was unclear whether the heat caused the power problems with the line-calling system, with investigations at the venue a few kilometres away from Wimbledon continuing.
Line judges were abolished last year at Wimbledon for the first time in the tournament's history in favour of the automated electronic system.
It is not the first time this week that the system has caused problems, with play also impacted on Monday when the audio 'out' calls were temporarily silenced.
Wimbledon's heat rule was in force on Wednesday, allowing a 10-minute break between the second and third set when the heat stress index reached 30.1 degrees Celsius.
Heat stress index readings, combining air temperature, humidity and court surface conditions, are taken 30 minutes before play and at 1400 and 1700 local time.
Unlike at the other Grand Slams, Wimbledon's qualifying tournament takes place off site at the former Bank of England sports ground in Roehampton, near the National Tennis Centre.
Plans to re-develop a golf course opposite the All England Club and move qualifying there have been approved but are still subject to a legal process.
(Reporting by Martyn Herman; Editing by Hugh Lawson)
