The invention relates to an installation for coating objects, said installation having, in a manner known per se, a coating chamber which is arranged upstream from a drying chamber. Among other features, the steering wheel has a pair of lower spokes that are deformable to absorb energy in a collision. A conductive layer extends over one of the interior surface of the diaphragm portion of the sidewall and an exterior surface of the diaphragm portion; and the conductive layer is coupled to the ground contact to either shield or ground the first electrode plate.