The coalescence of water drops, dispersed in oil, is critical to the destabilization of a water-in-oil emulsion under an electric field. In this work, we determine the conditions for coalescence or non-coalescence of two aqueous water drops that are suspended in an insulating oil and subjected to a uniform electric field. Specifically, we investigate the effect of the conductivity of the droplet phase (a), the type of oils (silicone oil and castor oil), the effect of waveform AC and DC and frequency, and the separation between the droplets on the electrocoalescence/non-coalescence of two suspended aqueous drops. The main highlights are, (i) we provide expressions for critical electrocapillary number (Ca-c) vs. sigma for silicone,oil (Ca-c = 0.010 x sigma(-0.20)) that shows cone-cone and castor oil (Ca-c = 0.022 x sigma(-15)) that shows cone-dimple mode of contact. (ii) Two closely spaced drops can coalesce at electrocapillary numbers much higher than the critical electrocapillary number for widely spaced drops due to a smaller cone angle at the point of contact. These results should be important in the design of industrial electrocoalescers. (C) 2019 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.