Abstract: An electrostatic precipitator unit used for the removal of coolant liquid and particles generated by a machine tool includes an electrostatic precipitator cell. The electrostatic precipitator cell includes power and collector ground fins and an ionizer grid positioned below the fins. The lower edges of the power fins are spaced above the collector ground fins to prevent contact of the liquid on the ground fins with the power fins. An electrical contact assembly for supplying electrical current to the ionizer grid and power fins is electrically isolated from all ground contacts by dielectric standoffs which define an insulating air gap. The likelihood of liquid tracking to ground is therefore eliminated.