Location-Allocation will assign each of the 2000 inspection sites to the closest of the three facilities.
This may not be the solution you are looking for. Perhaps you can use the Vehicle Problem Solver to solve this. Make your 2000 inspection locations as Orders. Make your three facilities as depots and add three routes, one for each depot. Set each Depot to have a capacity of 667 and solve. You may have to adjust the capcity and relax some constraints but you should have a reasonable solution.
Jay Sandhu