Siemens is supplying the project with 50 of its 2.3MW machines, which is due to be operational in June 2014.
According to Windpower Intelligence, Chile has a 4.9GW pipeline from 2014 until 2016.
The American power company has also passed the mid-way point of construction of its 270MW South Kent Wind project in the Chatham-Kent municipality in southern Ontario.
Fifty Siemens SWT-2.3-101 have been installed, after construction started on 1 April, and is due to be operational in April 2014.
Mike Garland, Pattern’s CEO, said: "We’re making excellent progress on our two projects in construction and are on track to complete them on time.
"These two premier wind projects, El Arrayan and South Kent, will be the largest wind power facilities in Chile and Ontario, respectively."