OR-Library is a collection of test data sets for a variety of OR problems.
A full list of the test data sets available in OR-Library can be found here.
There is one data file, pmedcap1 This file contains the problems solved in:  I.H. Osman and N. Christofides, Capacitated clustering problems by hybrid simulated annealing and tabu search, International Transactions in Operational Research, Vol. 1, No. 3, (1994) pp317-336. The format of the data file is: Number of problems (M) For each problem m (m=1,...,M) in turn: Problem number in , best solution value found in  Number of customers (n), number of medians (p), capacity of each median (Q) For each customer i (i=1,...,n) in turn: customer number (i), x coordinate of i, y coordinate of i, demand of i Note here that the computational results reported in  used euclidean distances calculated from these coordinates but rounded down to the nearest integer. These problems were contributed by Dr Ibrahim H. Osman Institute of Mathematics and Statistics, University of Kent, Canterbury, Kent CT2 7NF, UK E-mail: I.H.Osman@ukc.ac.uk Tel: +44 (0) 1227-764000 ext 7893 Fax: +44 (0) 1227-475 453 The data file is of size 20KB (approximately).
Click here to access this file
Other capacitated p-median test problems are also available here