The Hamiltonian operator for an unbiased array of Josephson junctions with
gate voltages is constructed when only Cooper pair tunneling and charging e
ffects are taken into account. The supercurrent through the system and the
pumped current induced by changing the gate voltages periodically are discu
ssed with an emphasis on the inaccuracies in the Cooper pair Dumping. Renor
malization of the Hamiltonian operator is used in order to reliably paramet
rize the effects due to inhomogeneity in the array and nonideal gating sequ
ences. The relatively simple model yields an explicit, testable prediction
based on three experimentally motivated and determinable parameters.