PORTLAND — Panera Bread Co. will open a nonprofit restaurant Monday in Portland where customers can pay what they wish for food. It’s the third “Panera Cares” community cafe for the company and its first West Coast location.

Panera opened community cafes last year in Clayton, Mo., and Dearborn, Mich. The restaurants are owned and operated by a nonprofit arm of the national restaurant chain, which receives no profit from the business.

“In some ways, it is a test for humanity,” said Ron Shaich, founder of Panera who launched the concept for the company. “Will people step up and help each other or will they take advantage?”

The company is converting an existing Panera restaurant in the Hollywood neighborhood into the community cafe format.

Panera looked at a number of potential sites around the country but said that it felt the “sensibility” of Portland suited the project.

If there is excess revenue, Shaich said it will be reinvested in the community such as using the cafe as a work-training site for at-risk youth.

“I think the people of Portland will do the right thing,” Shaich said.