New experimental results and their physical analysis are presented to clarify the behavior of a relatively stable self-arranged droplet cluster levitating over the locally heated water surface. An external electric field of both opposite directions leads to a significant increase in the rate of a condensational growth of droplets in the cluster. The experimental data are used to estimate a small electrical charge of single droplets and the attraction force of polarized droplets to the water layer. It is confirmed that the interaction between the droplets is governed by aerodynamic forces. (C) 2018 Elsevier Ltd. All rights reserved.